Why does my arm shake when I flex


Muscles That Vibrate, Jitter, Tremor, Or Shake When Used

Written by: Jim Folk.
Medically reviewed by: Marilyn Folk, BScN.
Last updated: September 23, 2019

Muscles that shake, vibrate, jitter, or tremor when used are often symptoms of anxiety disorder, including generalized anxiety disorder, social anxiety disorder, panic disorder, and others.

To see if anxiety might be playing a role in your anxiety symptoms, rate your level of anxiety using our free one-minute instant results Anxiety Test or Anxiety Disorder Test. The higher the rating, the more likely it could be contributing to your anxiety symptoms, including muscles that shake when you use them.

This article explains the relationship between anxiety and muscles that vibrate, shake, jitter, or tremor when used.

Common descriptions of the muscles that shake, vibrate, jitter or tremor when used anxiety symptoms

  • Your muscles vibrate, jitter, tremor, or shake when they are used or moved. For example, you experience shaking, tremors, vibrating, or jitteriness when raising or lowering an arm or leg.
  • You notice your arms, legs, hands, fingers, feet, or toes are shaky when you use them.
  • Even though you aren’t having muscle twitches or tremors when still, you notice you are when you are moving around or when using one, a few, or many of your muscles.

This muscles shakes when used anxiety symptom can affect one muscle or muscle group in the body, many muscles and muscle groups, or all muscles and muscle groups.

This muscle tremors when used anxiety symptom can come and go rarely, occur frequently, or persist indefinitely. For example, you notice a muscle or muscle group shakes or vibrates once in a while and not that often, shakes or vibrates frequently, or shakes or vibrates all the time.

This symptom can precede, accompany, or follow an escalation of other anxiety sensations and symptoms, or occur by itself.

This symptom can precede, accompany, or follow an episode of nervousness, anxiety, fear, and elevated stress, or occur “out of the blue” and for no apparent reason.

Muscle shakes, vibrates, jitters, and tremors when used anxiety symptoms can range in intensity from slight, to moderate, to severe. It can also come in waves, where it’s strong one moment and eases off the next.

This symptom can change from day to day and from moment to moment.

All of the above combinations and variations are common.

What causes muscles that shake, vibrate, jitter or tremor when used anxiety symptoms?

Medical Advisory

We recommend all new, changing, persistent, and returning anxiety symptoms be discussed with your doctor as some medical conditions and medications can cause anxiety-like symptoms, including this anxiety symptom. If your doctor concludes your symptoms are solely anxiety-related, you can be confident there isn’t a medical cause. Generally, doctors can easily determine the difference between anxiety symptoms and those caused by a medical condition.

Doctors aren’t infallible, however. If you are uncertain about your doctor’s diagnosis, you can seek a second or more opinions. But if all opinions agree, you can be assured anxiety is the cause of this symptom.

1. Active Stress Response

When this symptom is caused by anxiety, behaving in an apprehensive manner, which creates anxiety, causes the body to activate the stress response. The stress response causes the body to secrete stress hormones into the bloodstream where they travel to targeted spots to bring about specific physiological, psychological, and emotional changes that enhance the body’s ability to deal with a threat—to either fight with or flee from it—which is the reason the stress response is often referred to as the fight or flight response or the emergency response.

A part of the stress response changes include body-wide stimulation and tense muscles. This combination can cause muscles to shake, vibrate, jitter or tremor when used.

2. Stress-Response Hyperstimulation

When stress responses occur infrequently, the body can recover relatively quickly from the physiological, psychological, and emotional changes the stress response brings about. When stress responses occur too frequently, however, the body doesn’t completely recover. This can result in the body remaining in a state of semi stress response readiness, which we call “stress-response hyperstimulation” since stress hormones are stimulants. This state is also often referred to as “hyperarousal.”

A body that becomes hyperstimulated can exhibit all of the changes of an active stress response even though a stress response hasn’t been activated. Experiencing muscles that “shake, vibrate, tremor, and jitter” when using them is a common indication of hyperstimulation.

While this symptom can be bothersome, it isn’t harmful. This symptom, like all anxiety-related sensations and symptoms, is just a symptom of stress, and therefore, needn’t be a cause for concern.

And like all other sensations and symptoms of stress, this symptom diminishes and eventually subsides when hyperstimulation is eliminated.

How to stop the muscles shake, vibrate, jitter or tremor anxiety symptoms?

When this anxiety symptom is caused by apprehensive behavior and the accompanying stress response changes, calming yourself down will bring an end to the stress response and its changes. As your body recovers from the active stress response, this anxiety symptom should subside. Keep in mind that it can take up to 20 minutes or more for the body to recover from a major stress response. But this is normal and shouldn’t be a cause for concern.

When this anxiety symptom is caused by hyperstimulation, such as from overly apprehensive behavior, it may take much longer for the body to calm down and recover, and to the point where this anxiety symptom subsides.

Nevertheless, when the body has recovered from hyperstimulation, this anxiety symptom will subside. So again, this anxiety symptom needn’t be a cause for concern.

You can speed up the recovery process by reducing your stress, practicing relaxed breathing, increasing your rest and relaxation, and not worrying about your anxiety symptoms.

Yes, these types of symptoms can be bothersome, but again, when your body has recovered from the stress response or the effects of hyperstimulation, this symptom will subside.

If you are having difficulty containing your worrying, you may want to connect with one of our recommended anxiety disorder therapists. Working with an experienced anxiety disorder therapist is the most effective way to overcome anxiety disorder and its symptoms, including what seems like uncontrollable worry.

For a more detailed explanation about anxiety, anxiety symptoms, why anxiety symptoms can persist long after we think they should, common barriers to recovery and symptom elimination, and more recovery strategies and tips, we have many chapters that address this information in the Recovery Support area of our website.

The combination of good self-help information and working with an experienced anxiety disorder therapist is the most effective way to address anxiety disorder and its many symptoms. Until the core causes of anxiety are addressed – the underlying factors that motivate apprehensive behavior – a struggle with anxiety disorder can return again and again. Identifying and successfully addressing anxiety’s underlying factors is the best way to overcome problematic anxiety.

Additional Resources:

  • For a comprehensive list of Anxiety Disorders Symptoms Signs, Types, Causes, Diagnosis, and Treatment.
  • Anxiety and panic attacks symptoms can be powerful experiences. Find out what they are and how to stop them.
  • How to stop an anxiety attack and panic.
  • Free online anxiety tests to screen for anxiety. Two minute tests with instant results. Such as:
    • Anxiety Test
    • Anxiety Disorder Test
    • OCD Test
    • Social Anxiety Test
    • Generalized Anxiety Test
  • Anxiety 101 is a summarized description of anxiety, anxiety disorder, and how to overcome it.

Return to Anxiety Disorders Signs and Symptoms section.

anxietycentre.com: Information, support, and therapy for problematic anxiety and its sensations and symptoms, including the muscles that vibrate, jitter, tremor, or shake when used anxiety symptom.

1. Selye, H. (1956). The stress of life. New York, NY, US: McGraw-Hill.

2. Folk, Jim and Folk, Marilyn. “The Stress Response And Anxiety Symptoms.” anxietycentre.com, August 2019.

3. Hannibal, Kara E., and Mark D. Bishop. “Chronic Stress, Cortisol Dysfunction, and Pain: A Psychoneuroendocrine Rationale for Stress Management in Pain Rehabilitation.” Advances in Pediatrics., U.S. National Library of Medicine, Dec. 2014.

4. Justice, Nicholas J., et al. “Posttraumatic Stress Disorder-Like Induction Elevates β-Amyloid Levels, Which Directly Activates Corticotropin-Releasing Factor Neurons to Exacerbate Stress Responses.” Journal of Neuroscience, Society for Neuroscience, 11 Feb. 2015.

Why Your Muscles Shake During a Hard Workout

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Pushing yourself during a workout is rarely a bad thing, and going so hard that your muscles start to shake is certainly a sign that you’re at your max-but your body may also be trying to tell you something. While many people pass this off as a simple sign that they’re out of shape, and a majority of my fitness colleagues would agree that this trembling is not a great cause for concern, it could also lead to injury if you’re not careful to use proper form.

Let’s explore why your muscles may quiver during a barre class, Pilates, strength workout, or other type of exercise-and what to do about it.

1. Inadequate sleep. If you are heading into a cardio or strength training session feeling lethargic or lacking a good night’s rest, you will probably experience tremors at some point in your routine. The body continues to grow and heal when it gets the proper amount of sleep, and disrupting this can cause your muscles to stay locked in a catabolic-like state. If you’ve been skimping on sleep, I recommend you skip the gym and stay in bed (if you work out in the morning) or head to bed early (if you’re a p.m. exerciser).

2. Going to extremes. With fitness crazes like CrossFit and endurance events like Tough Mudder becoming the staple in mainstream fitness, people are really pushing themselves to the extremes these days. However, take caution and implement mandatory rest days into your fitness routine. Learn how to take a proper rest day so that you can maintain a sustainable workout routine and stop the shakes for good.

3. Too new, too much, too soon. If you try a new fitness class or jump into a new routine, at some point during your workouts you may feel your body start to wobble because working different muscles than you’re used to may be too much, too soon. While it may not be a cause for great alarm, it’s probably best to lighten up. You could place stress on other parts of your body in order to compensate for weaker muscles, which may cause injury. For example, if it’s your first time performing burpees, by the fourth or fifth one your legs may start to shake. Instead of resting, you decide to continue but with bad form, which can strain your lower back. Bad idea.

4. Dehydration. Your workout can be one of the best indicators of whether or not you are hydrated. When your body is low on water, your muscles and connective tissues have difficulty performing what they are meant to do, as improper hydration can cause an imbalance of your electrolytes, which are involved in muscle contraction. I recommend drinking half of your body weight in ounces daily. Remember, if you’re thirsty, you’re dehydrated.

Getting a Handle on MS Tremors and Shakes

Many people with multiple sclerosis (MS) develop tremors, or shaking, in various body parts. Tremors can be mild, but they can also be severe and disabling.

“MS tremors are rhythmic, back-and-forth muscle movements that you can’t control,” says Alessandro Serra, MD, PhD, a neurologist at University Hospitals Cleveland Medical Center in Ohio. “The tremor can affect your hands, arms, legs, or even your head and vocal cord muscles.”

People with MS get tremors when plaques, or damaged areas, develop along the nerve pathways responsible for voluntary muscle movement and balance.

How much of an impact they have on a person’s life varies from one individual to another.

Dario Anastasio, 62, of Newington, Connecticut, had to give up his job as a computer systems engineer because of his tremors.

“Before I was diagnosed with MS, I would have tremors in my hands, but I could still write and use a computer,” Anastasio says. The tremors worsened after his 2007 diagnosis with MS.

Linda Roudebush, 62, of Austin, Texas, is not so troubled by the tremors in her left hand. “I am right-handed,” she says. “So the tremor in my left hand is an inconvenience, but not all that bothersome. I don’t take anything for it, and I use the shaking hand to scratch an itch or give a back massage,” she jokes.

Different Types of Tremors

Tremors are commonly classified by appearance and cause or origin:

Cerebellar tremor, the kind most often associated with MS, is a slow tremor of the extremities “caused by lesions in or damage to the cerebellum in the brain,” says Harold Gutstein, MD, a MS neurologist at NYU Langone Health in New York City.

“In MS, these tremors reflect more aggressive or long-lasting disease,” Dr. Gutstein says. Cerebellar tremors tend to occur at the end of purposeful movement, such as pressing an elevator button with a finger.

Tremors are also described according to the situations in which they occur:

Intention tremor tends to occur at the end of a purposeful movement, such as touching a finger to the tip of your nose. “These occur when you reach for something and start to shake,” Dr. Serra says.

Postural tremor occurs when you’re holding a position against gravity, such as holding your arms outstretched. “With these tremors, you shake when you sit or stand,” Gutstein says, “but not when you’re lying down.”

Resting tremor occurs at rest and is more common in Parkinson’s disease than in MS, but it does occur in MS.

How to Prevent MS Tremors

Gutstein often tells his patients: “The brain is like time: Once it disappears, you’re not getting it back.”

The important thing is to get diagnosed and get early, aggressive treatment with available disease-modifying MS drugs that can prevent most tremors from ever occurring, he says. “There are about 15 medications now for the treatment of MS, and some of them are very effective.”

To minimize tremors, “you should also eliminate contributing factors that can be controlled, like fatigue, stress, or too much coffee,” Gutstein says. “There are no great treatments for MS tremors once they start, which is why prevention is so important.”

How to Cope With MS Tremors

For those who have already developed tremors, treatment may include the following:

Occupational or physical therapy can help you manage tremors that interfere with daily life. These therapies may include the use of braces, weighted devices, wrist rests, and exercises to increase control and balance, Serra says.

Medication, including anti-anxiety drugs, antihistamines, beta-blockers, anti-nausea medication, and anti-seizure drugs have all been used for tremors caused by MS. “No drug has been specifically approved for MS tremors,” Serra says. “None of the available MS drugs treat tremors, either.”

Deep brain stimulation, a therapy often used to treat Parkinson’s disease, may also be helpful for cases of severe MS tremor. It involves implanting electrodes into the brain to block involuntary muscle movement, Serra explains.

Anastasio underwent deep brain stimulation on the left side of his brain to control the tremors on the right side of his body. “I can now hold my right hand without shaking, but my left one still has tremors,” he says. He has not decided whether to have the treatment on the other side of his brain.

“Deep brain stimulation shows promise,” Serra says, “but the improvements are not always dramatic enough to justify the risks.” Those include infection and bleeding in the brain, he says.

Botox, which is approved to treat MS-related spasticity in the upper and lower limbs, as well as overactive bladder, may also help treat MS-related limb tremors. In a study published in the journal Neurology, 23 people with MS showed improvement in tremor severity in their arms as well as in their writing and drawing ability six weeks and three months after Botox shots.

When injected into a muscle, Botox blocks nerve signals that cause tightening and movements of the muscle. Its effects last between two and six months.

What About Medical Marijuana for MS Tremors?

Medical marijuana has not yet been proven to help with tremors, Gutstein says.

Indeed, a review of clinical and preclinical research on marijuana and other chemicals (cannabinoids) derived from the cannabis plant published in February 2015 in the journal Movement Disorders found that cannabinoid-based therapies probably had no benefit for tremors in MS.

“There is a lot of noise out there,” Gutstein says, “but cerebellar lesions. It’s a step I wouldn’t cross at this point.”

Additional reporting by Susan Jara.

Nonmedicinal Tremor Treatments

  • Braces: These can hold your joint still and stop extra movement. A brace on your ankle or foot can make it easier to walk. They can help control your arm, hand, or neck, too.
  • Deep brain stimulation: This experimental approach is mostly used for people who have tremors from Parkinson’s disease. A doctor implants electrodes into your brain. Wires connect them to a gadget in your chest. You use it to send your brain signals that stop the tremors.
  • Medical cannabis: There’s little evidence that cannabis can help with tremors, but study results are mixed and usually only include small numbers of people.
  • Physical therapy: It can show you exercises that increase your range of motion, improve your posture and balance, and make your body more stable
  • Speech therapy: If you have tremors in your lips, tongue, or jaw, a health professional can work with you to slow your speech, make it clearer, and control the volume.
  • Occupational therapist: This person will set you up with special tools called adaptive or assistive devices. They can help you grab things from up high or off the floor, pull up a zipper, or hold a fork more easily.
  • Weights: Adding extra weight to a body part can help keep it still. You can also add weights to commonly used items like forks, pencils, pens, eating utensils, canes, and walkers.

Distinguishing Essential Tremor From Parkinson’s Disease

Essential tremor (ET) is at least eight times more common than Parkinson’s disease (PD). There are many differences in the presentation, course and treatment of ET and PD; however, these differences are not always recognized by healthcare professionals and misdiagnoses are common (Table 1). It has been suggested that up to 20 percent of patients with ET may develop PD, but whether ET is a risk factor for PD remains a controversial issue.1

Signs and Symptoms

Usually ET starts as a low- amplitude tremor but can gradually increase to a coarse, disabling tremor. As ET progresses, tremor frequency (number of repetitions per second) may decrease; however, tremor amplitude (magnitude/strength) may increase. Increased amplitude is associated with a decreased ability to manage fine motor tasks. The amplitude varies up to 23 percent throughout the day, but the frequency usually does not change during the course of the disease.2

ET generally presents bilaterally and is primarily seen during action, such as when writing or eating, or when holding a posture, for example, when holding an object against gravity. On the other hand, parkinsonian tremor most often presents unilaterally and later progresses to include both sides of the body. PD tremor most commonly occurs at rest, when the body part is relaxed and not in use, but can also be seen in the postural position, often referred to as reemergent tremor.3

ET most commonly affects the hands, legs, head, and voice, and tremor is the primary symptom of ET. In PD, the cardinal symptoms include bradykinesia, rigidity, tremor, and gait/balance issues. It is important to note that although it occurs in the majority, tremor does not have to be present to make a diagnosis of PD. The tremor of PD most generally occurs in the upper/lower extremities and the chin/jaw and generally does not affect the head or voice.

ET most commonly onsets during middle age, but can occur at any time in the lifespan, even in childhood. The progression of ET can be variable. In some patients ET remains mild throughout the lifespan and does not result in significant disability; however, in others ET progresses and can cause significant disability, making many daily activities very difficult or impossible to complete. On the other hand, the average age of onset of PD is 60 years although it may be much later and about 10 percent present prior to the age of 40 years. PD is a progressive disorder with virtually all patients having increased disability over time.

Although the gene accounting for the majority of ET patients has not been identified, ET is an autosomal dominant disorder with greater than 50 percent of patients reporting a family history of tremor. It is not uncommon to have a patient report multiple family members from several generations that have been affected by tremor. PD is the result of a loss of dopamine in the substantia nigra; however, the cause of PD is currently unknown and it is suspected that it may be a combination of a genetic predisposition and environmental influences. A family history of PD is reported in less than 20 percent of patients.

Both ET and PD are affected by stress, anxiety and emotion and it is not uncommon to see an increase in tremor under stressful conditions.


At this time, there are no tests that can definitively diagnose either ET or PD and it is not uncommon to have the two mistaken for each other. The diagnosis is based on a complete medical/symptom, family and medication history and an examination by a physician, preferably a neurologist who specializes in movement disorders. Obtaining a handwriting sample may be helpful in making an accurate diagnosis; in ET handwriting is generally large and tremulous, whereas in PD, micrographia (very small handwriting) is common. DaTscan, a single photon emission computed tomography (SPECT) scan, which measures dopamine uptake, has been approved as a diagnostic aid to help physicians differentiate between ET and parkinsonian tremor.4 Other imaging techniques are under investigation to determine their utility in differentiating ET and PD. An accurate diagnosis is critical as the treatment regimen is very different for the two disorders.


Alcohol has been known for decades to improve ET; however, it generally has little to no effect on PD.5 Excessive use of alcohol is not recommended due to the potential for abuse; however, judicial use of alcohol prior to a social or stressful event can be helpful. Currently, treatments are under investigation for ET based on the dramatic effect often seen with ethanol.

The first-line pharmacological treatments for essential tremor include propranolol and primidone. They can be used individually or in combination if needed. Other treatments include gabapentin, topiramate and benzodiazepines, which can be particularly helpful in ET patients with significant anxiety.6,7 Botulinum toxin injections may be helpful in ET but they are used less frequently and can result in weakness.

On the other hand, pharmacological treatments for Parkinson’s disease to date have focused on dopamine depletion and include carbidopa/levodopa, dopamine agonists such as ropinirole, pramipexole and rotigotine monoamine oxidase type B (MAO-B) inhibitors such as rasagiline and selegiline, and less commonly amantadine and anticholinergics.8

For both ET and PD, deep brain stimulation (DBS) can be an effective treatment. In ET, DBS is an option if adequate control of symptoms cannot be obtained with medications. The most common site for DBS is the ventral intermediate nucleus of the thalamus. In PD, DBS is an option when medications are not consistently controlling symptoms throughout the day. For PD, DBS is generally done in the subthalamic nucleus or the globus pallidus interna.


ET and PD are both movement disorders for which tremor is a primary symptom and therefore, the two are often mistaken for each other. However, there are many differences between the signs and symptoms of the two disorders and it is critical that patients receive an accurate diagnosis early in the disease process such that they can receive the appropriate treatment, education and support.

Dr. Jankovic is Professor of Neurology, Distinguished Chair in Movement Disorders, Director, Parkinson’s Disease Center and Movement Disorders Clinic, Co-Director, Parkinson’s Disease Research Laboratory, Baylor College of Medicine, Department of Neurology, Houston, Texas; and IETF Medical Advisory Board.

  1. Fekete R, Jankovic J. Revisiting the relationship between essential tremor and Parkinson’s disease. Mov Disord 2011;26:391-398.
  2. Mostile G, Fekete R, Giuffrida JP, et al. Amplitude fluctuations in essential tremor. Parkinsonism & related disorders 2012;18:859-863.
  3. Jankovic J, Schwartz KS, Ondo W. Re-emergent tremor of Parkinson’s disease. Journal of neurology, neurosurgery, and psychiatry 1999;67:646-650.
  4. Hauser RA, Grosset DG. FP-CIT (DaTscan) SPECT brain imaging in patients with suspected parkinsonian syndromes. Journal of neuroimaging : official journal of the American Society of Neuroimaging 2012;22:225-230.
  5. Mostile G, Jankovic J. Alcohol in essential tremor and other movement disorders. Mov Disord 2010;25:2274-2284.
  6. Lyons KE, Pahwa R, Comella CL, et al. Benefits and risks of pharmacological treatments for essential tremor. Drug Saf 2003;26:461-481.
  7. Zesiewicz TA, Elble RJ, Louis ED, et al. Evidence-based guideline update: treatment of essential tremor: report of the Quality Standards subcommittee of the American Academy of Neurology. Neurology 2011;77:1752-1755.
  8. Fox SH, Katzenschlager R, Lim SY, et al. The Movement Disorder Society Evidence-Based Medicine Review Update: Treatments for the motor symptoms of Parkinson’s disease. Mov Disord 2011;26 Suppl 3:S2-41.

Understanding MS Tremors

Currently, there is no cure for tremors. But there are ways for people with MS to reduce their occurrence and improve function.

Lifestyle changes

The following lifestyle changes may help decrease the occurrence of tremors:

  • avoiding stress
  • getting enough rest
  • avoiding caffeinated drinks

Physical and occupational therapy

Physical and occupational therapists can help people with MS control tremors by:

  • teaching exercises for coordination and balance
  • recommending stabilizing braces in certain cases
  • demonstrating how to use weights to compensate for tremors
  • teaching new ways of performing daily activities that MS tremors might make challenging


A consistently effective drug for tremors hasn’t yet been identified. According to the National Multiple Sclerosis Society, however, health professionals have reported varying degrees of success in treating tremors in people with MS using drugs including:

  • beta-blockers, such as propranolol (Inderal)
  • anti-anxiety medications, such as buspirone (Buspar) and clonazepam (Klonopin)
  • anticonvulsive drugs, such as primidone (Mysoline)
  • antituberculosis medication, such as isoniazid
  • antihistamines, such as hydroxyzine hydrochloride (Atarax) and hydroxyzine pamoate (Vistaril)
  • diuretics, such as acetazolamide (Diamox)


A 2012 study indicated that the same Botox (botulinum toxin type A) injections used to temporarily smooth facial lines significantly improved arm tremor in people with MS.


People with MS who have severe disabling tremors despite medications may be good candidates for surgical treatment.

There are two types of surgery that may help tremors in people with MS: thalamotomy and deep brain stimulation.

Thalamotomy is a surgery that destroys a part of the thalamus, a structure in the brain that helps control movements.

Deep brain stimulation implants a tiny electrode into the thalamus. The electrode is then attached to a wire that connects to a device under the skin in the chest area. The device delivers small electrical impulses to the thalamus.

Deep brain stimulation isn’t approved by the U.S. Food and Drug Administration (FDA) for treatment of MS-related tremor. However, it has been used successfully for this purpose.

Multiple sclerosis seizures, tremors, tingling, twitching

Even though epileptic seizures are more common in people with multiple sclerosis , it’s not by a lot. Only about 8% of people diagnosed with this disease ever experience a seizure. Around 2%-3% of them have regularly active seizures. Researches still don’t show why exactly seizures happen more to those with multiple sclerosis, but it is noticed that they are more frequent when the disease flares up. Luckily, those who go through seizures can usually successfully control them with medication such as carbamazepine and phenytoin.

People with multiple sclerosis can also experience tremors. They are characteristic for creating shaking movements that can’t be controlled willingly and can appear in any part of a body, but is the most common in the arms and legs. They can be very visible, or only detectable by the person having them. There are the two main types of tremors: intention tremors and postural tremors. Intention tremors are those that happen only when a person is moving. This creates a number of problems in everyday life, including social aspect of a person’s life and can cause depression because of it. The second one, postural tremors, is less common than intention tremors and is experienced when a person is standing or sitting, but not when lying down. Sometimes resting tremor can also occur in a person suffering from multiple sclerosis (happens while resting), but it is very rare and more known as a part of Parkinson’s disease.

Those suffering from multiple sclerosis may also experience signs of tingling and twitching. Tingling is characteristic especially as an early sign of the disease. Muscle twitching could be one of the symptoms as well, but as with most of the other symptoms, it varies from person to person, and not everybody experience the same things.

Multiple Sclerosis true stories after stem cells treatment

Tremor is defined as an unintentional, rhythmic, oscillatory muscle contraction causing shaking movements of one or more parts of the body. It can affect the hands, head, face, jaw, lips, torso, and legs. Sometimes the voice may be affected as well.

Hand tremor is the most common form.

Tremor is a normal physiologic phenomenon. Most of us see our hands shaking slightly when we hold them out in front of us. Several factors, such as stress, anxiety, lack of sleep, smoking, and caffeine may exaggerate this tremor.

Although tremor is usually not a sign of a severe or life-threatening medical disorder, it can be both embarrassing and disabling to some people and make it harder to perform work and daily life tasks.

Tremor may occur at any age but is most common in middle-aged and older adults. It tends to affect men and women equally.

Tremors are classified as rest or action tremors.

Rest tremor occurs when the affected body part is completely supported against gravity. It may be an arm or a hand that is resting in the patient’s lap. Action tremors, on the other hand, are produced by voluntary muscle contraction. They may occur when writing or lifting a cup of coffee.

Postural tremor is a sub-type of action tremors and occurs when the person maintains a position against gravity such as holding the arms outstretched (1). Postural and action tremors, including exaggerated physiologic tremor and essential tremor, comprise the largest groups.


1. Exaggerated Physiologic Tremor

All normal persons exhibit physiologic tremor. However, it may often be invisible to the naked eye.

Physiological tremor is most evident in the outstretched hands but can be detected in the legs, head, trunk, jaw, and lips.

Enhanced physiologic tremor may be caused by medical conditions such as thyrotoxicosis (overactive thyroid gland), hypoglycemia (low blood sugar), the use of certain drugs, or withdrawal from alcohol, opioids or benzodiazepines. It is usually reversible once the cause is corrected (2).

Beta blockers, also known as beta-adrenergic blocking agents, are medications that may be used to reduce the amplitude of trembling during fine manual work (3). Beta blockers work by blocking the effects of the hormone epinephrine, also known as adrenaline. They are often used to treat high blood pressure (4), heart palpitations (5) and tremor due to an overactive thyroid gland.

2. Essential Tremor

Essential tremor is the most common neurologic disorder that causes postural or action tremor. It is also the most common movement disorder worldwide.

The prevalence increases markedly with age and ranges from 4.1 to 39.2 cases per 1,000 persons, to as high as 50.5 per 1,000 in persons older than 60 years (6). These figures may underestimate the actual prevalence, however, because up to 50 percent of persons with mild essential tremor are unaware of it (7).

More than half of patients with essential tremor have a family history of the disorder (8).

Essential tremor usually develops insidiously and progresses slowly. It often occurs first in the hands and forearms and may be more prominent on one side of the body and increases with goal-directed activity (e.g., drinking from a glass of water or writing).

Essential tremor may also affect the head, voice, jaw, lips, and face. It can include a”yes-yes” or “no-no” motion of the head.

The shaking usually increases with stress, fatigue, and certain medications such as central nervous stimulants. It may also increase with specific voluntary activities such as holding a spoon or a cup.

Interestingly, there is often a degree of voluntary control. Hence, the trembling may be suppressed by performing skilled manual tasks (9).

Although sometimes disabling, essential tremor is in itself a benign disorder and not life-threatening.

Rest, beta blockers, primidone (Mysoline), and alcohol ingestion decrease the trembling.

Primidone and propranolol are the cornerstones of maintenance medical therapy for essential tremor. These medications provide clinical benefit in approximately 50-70% of patients (10).

3. Parkinson’s Disease

Although Parkinson’s disease is probably 20 times less common than essential tremor, about one million Americans suffer from the disease (11).

Tremor is a common symptom of Parkinson’s disease and other Parkinsonian syndromes. However, it is not experienced by all patients with Parkinson’s disease.

The tremor includes shaking in one or both hands at rest. It may also affect the chin, lips, face, and legs. The shaking may initially appear in only one limb or on just one side of the body. It is often made worse by stress, strong emotions, and after exercise.

Sometimes, the trembling only affects the hand or fingers. This type of shaking is often seen in people with Parkinson’s disease and is called a “pill-rolling” tremor because the circular finger and hand movements resemble rolling of small objects or pills in the hand.

Although the trembling of Parkinson’s disease is usually defined as a resting tremor, more than 25 percent of people with Parkinson’s disease also have an associated action tremor (11).

The trembling of Parkinson’s disease differs from essential tremor in three fundamental ways (12):

  • Essential tremor is more likely to occur during voluntary activity of the hands whereas the trembling of Parkinson’s disease is more prominent at rest.
  • Parkinson’s disease is usually associated with stooped posture, slow movement, and shuffling gait.
  • Essential tremor mainly involves the hands, head, and voice. Parkinson’s disease tremors usually start in the hands and arms but also affect the legs, chin, and other parts of your body.

Although Parkinson’s disease can’t be cured, medications may markedly improve symptoms.


4. Intention Tremor (Cerebellar Tremor)

Intention tremor, also known as cerebellar tremor, presents as a unilateral or bilateral shaking, most often caused by stroke, brainstem tumor, or multiple sclerosis (2).

The neurological examination will reveal that finger-to-nose, finger-to-finger, and heel-to-shin testing result in increased shaking as the extremity approaches the target. Other signs include abnormalities of gait, speech, and ocular movements and inability to perform rapid alternating hand movements.

That the shaking typically increases in severity as the hand moves closer to its target, is in contrast to postural and action tremor (like essential tremor), which either remains constant throughout the range of motion or abruptly increase at terminal fixation (13).

Ataxia, a lack of voluntary coordination of muscle movements that includes gait abnormality, is typically associated with cerebellar tremor.

In cerebellar tremor, the finger-to-nose, finger-to-finger, and heel-to-shin testing result in worsening tremor as the extremity approaches the target.

5. Wilson Disease

Wilson disease is a rare autosomal recessive inherited disorder of copper metabolism that is characterized by excessive deposition of copper in the liver, brain, and other tissues (14). Wilson disease is often fatal if not recognized and treated when symptomatic.

Liver dysfunction is the presenting feature in more than half of patients.

The most common presenting neurologic feature is an asymmetric tremor, which is variable in character.

Wilson disease may also be associated with difficulty speaking, excessive salivation, ataxia, clumsiness with the hands, and personality changes.

6. Rubral Tremor

Rubral tremor, also known as Holmes tremor, is a rare symptomatic movement disorder, characterized by a combination of resting, postural, and action tremors.

It is usually caused by lesions involving the brainstem, thalamus, and cerebellum.

The disorder is often difficult to treat. Many medications have been used with varying degrees of success (15).

7. Primary Writing Tremor

Shaking that occurs exclusively while writing, and not during other voluntary motor activities, is referred to as primary writing tremor. Hence, it is a task-specific tremor that predominantly occurs and interferes with handwriting (16).

The cause and pathophysiology of this disorder are still unknown. It has been classified as a focal form of essential tremor and as a tremulous form of writer’s cramp (17).

Botulinum toxin injections and deep brain stimulation may be treatment choices for primary writing tremor (18).

8. Orthostatic Tremor

Orthostatic tremor is a rare disorder, characterized by a rapid trembling limited to the legs and trunk (19). It occurs exclusively while standing.

The disorder is often associated with extreme straining of both legs, fatigue, unsteadiness and a fear of falling. Standing upright for only a short period may be difficult.

The shaking may disappear partially or completely when an affected person is walking or sitting.

There is controversy within the medical literature regarding whether orthostatic tremor is a variant of essential tremor, an exaggerated physiological response to standing still or a distinct clinical entity (20).

The disorder may respond to treatment with clonazepam or gabapentin (Neurontin) (21).

9. Functional Tremor (Psychogenic Tremor)

Functional tremor, also known as psychogenic tremor, is a variable tremor that may decrease or disappear when not under direct observation.

Functional tremor is classified as a functional movement disorder, a term that is applied to disorders that manifest with physical symptoms, specifically abnormal movements (gait disorders, tremor, dystonia, etc.) but which cannot be attributed to any of known underlying organic disorders and which instead is presumed to be due to “psychological factors” (22).

Any body part may be involved, but, remarkably, the fingers are often spared with much of the trembling of the arm occurring at the wrist (13).

A characteristic that suggests functional rather than organic tremors is abrupt onset with immediate maximal severity, often precipitated by trivial emotional or physical trauma (23).

Patients with functional tremor often have more than one movement disorder, which can be a helpful clue to the diagnosis.

10. Drug-Induced Tremors

Several medications can cause or exacerbate tremor (2).

Examples are amiodarone, atorvastatin, beta-adrenergic agonists (albuterol, terbutaline, salbutamol) carbamazepine, corticosteroids, fluoxetine, haloperidol, lithium, methylphenidate, synthetic thyroid hormones, tricyclic antidepressants, valproic acid, and verapamil.

The shaking may affect the hands, arms, head, or eyelids. It rarely affects the lower body and may not always affect both sides of the body equally (24).

Drug-induced tremor will usually disappear when the medication causing the symptoms is stopped.

If the benefit of the medicine is greater than the problems caused by the tremor, lowering the dose may sometimes be helpful.


You notice the shaking most in the morning, when you’re texting or drinking your coffee. Or it could be an all-the-time affliction, causing your hands to quiver whenever they’re hanging at your sides.

You’re not alone. A shaking or trembling body part—also known as a tremor—is the most common type of movement disorder, according to a 2011 study in American Family Physician. And your hands are the most likely part of your body to suffer.

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What’s causing your shakes? A hand tremor can stem from a number of underlying causes, ranging from diseases like Parkinson’s to a benign caffeine overload, says Joseph Jankovic, MD, a professor of neurology and distinguished chair in movement disorders at Baylor College of Medicine.

How can you tell what’s causing your hand shaking? In many cases, you can’t. But a doctor can based on when and how your tremor shows up.

MORE: 10 Reasons Your Hands Are Going Numb

For example, you might have an “action” tremor, which is the type that manifests when you’re lifting or manipulating something with your hands, Jankovic says. This sort of tremor may be most obvious when you’re working against gravity—like when you’re eating or drinking, or trying to pick something up and hold it in front of your face. You could also have a “rest” tremor, meaning your hand moves or trembles when it’s immobile or at your side, he says.

Regardless of the type of tremor you’re dealing with, if your shakes are interfering with your ability to function or are causing you embarrassment around other people, it’s time to see someone, Jankovic says. (Psst! Here are the 7 worst things people lie to their doctors about.)

Here, he and other experts explain the common causes of hand tremor—and how to tell one from another.

Essential tremor

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By far the most common form of chronic hand tremor—up to 1 in 25 people, or 4% of the population, may experience it—essential tremor is a shaking that comes on when you’re trying to perform some kind of work or action with your hands, says Gordon Baltuch, MD, PhD, a professor of neurosurgery at the University of Pennsylvania and associate director of the Parkinson’s Disease Research, Education and Clinical Center.

If your hand shakes when you’re trying to type or write, or you notice it most when you’re reaching to pick up a salt shaker or your drinking glass, that’s indicative of this form of tremor, Baltuch explains.

MORE: 9 Weird Things Your Hands Say About Your Health

It can be mild—almost unnoticeable—or so pronounced that you can’t complete daily tasks. But there’s one easy way to tell if what you’re experiencing is essential tremor: Have a stiff drink. “If you do and the tremor goes away, there’s your diagnosis right there,” he says.

In fact, drinking has long been a way for people with essential tremor to manage their shaking. Baltuch says patients have come to his office inebriated, and his office staff tried to send them home. “I had to tell them no, the patient has to drink in order to function,” he says.

This is your body on alcohol:

What causes essential tremor? “We don’t know,” he says. “We know that it runs in families, so there seems to be a genetic component, but we don’t really understand the cause of it.” He says it may be related to the way the cerebellum—a part of the brain that controls motor skills—sends and receives information. But the details are murky.

Essential tremor usually starts in one hand, often a person’s dominant hand, and eventually moves into the other hand. While your risk for essential tremor climbs as you age, it can show up at any time. “I have kids who come in with essential tremor,” Baltuch says.

What can you do about it? If it’s very mild, you don’t have to do anything. It may grow worse with age, or it may not. But leaving it untreated likely doesn’t lead to any issues down the road, he says. (These are the 6 best brain foods to eat as you age.)

If it is interfering with your life, there are drugs that can help. “The mainstay of treatment is beta blockers,” he says. “If those don’t work, some anticonvulsants may be effective.”

If drug treatments fail, some surgical operations are available. Baltuch performs a non-invasive form of ultrasound surgery that can be life-changing for patients with extreme cases.

MORE: 6 Signs You’re Headed For A Nervous Breakdown

Parkinson’s disease

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While essential tremor is apparent when your hands are active, the type of hand movement associated with Parkinson’s is called a “rest tremor” because it shows up when the hands are idle, says Michael Rezak, MD, PhD, director of the Movement Disorders and Neurodegenerative Diseases Center at Northwestern Medicine.

“When the arm is hanging at the side, or there is no muscle tone in the arm, that’s when this kind of tremor is most prominent,” Rezak explains.

Also, while essential tremor looks more like shaking, the type of tremor associated with Parkinson’s often has a kind of rhythmic quality to it, he says. For many patients, the tremor starts as a kind of “pill rolling” motion between the thumb and index finger. (This YouTube video demonstrates what that looks like.)

Parkinson’s is a neurodegenerative disease in which certain brain cells gradually die off. While it’s not well understood why that cell die-off starts, it leads to a shortage of the brain chemical dopamine, which eventually produces tremors, as well as other motor symptoms like facial tics, poor posture, and difficulty speaking. (This is what it’s like when your spouse has Parkinson’s.)

Parkinson’s tends to show up during a person’s 60s or later—although a small percentage of patients develop it younger, Rezak says. There is no cure for Parkinson’s, but medications and physical activity can help.


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Every living person has a very mild—basically, invisible—form of tremor that results from their heart beat, blood flow, and other processes going on inside their bodies. This is called a physiologic tremor. But under certain conditions, this tremor can become more pronounced, Jankovic says.

One of those situations: periods of high stress or anxiety. If your hands or voice have ever started shaking before a public speaking engagement—or if your leg was trembling when you looked over the edge of a tall building—you’ve experienced this sort of tremor, which is known as “enhanced physiologic tremor,” Jankovic explains.

MORE: 10 Silent Signals You’re Too Stressed Out

It may be annoying or embarrassing, depending on the situation. But unless you’re experiencing it all the time, and so feel like it’s negatively affecting your life, you don’t have to do anything about it, he says.

If you feel like this kind of stress-induced tremor is a major problem for you, tell your doctor. Stress-relief activities like meditation, yoga, or listening to music—as well as anti-anxiety meds—can help. (Try these 10 supereasy ways to de-stress in under a minute.)

Too much caffeine

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Just as stress can heighten your normally undetectable physiologic tremor, so can caffeine, Jankovic says. If you notice your hands shaking after coffee or other sources of caffeine, it’s time to cut back—or switch to half-caff. (These 6 physical symptoms mean you’re drinking too much coffee.)

That said, caffeine (and stress) can also make essential tremor more noticeable, he adds. If you think your tremors are more than a simple caffeine overload, let your doctor know about it.

MORE: 10 Cancer Symptoms Most People Ignore

Your meds

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Like stress and caffeine, some medications—notably, asthma medications like bronchodilators—can lead to hand tremors, Jankovic says. Amphetamines, some statins, and selective serotonin reuptake inhibitors (SSRIs) can also cause hand tremor.

If you notice your tremors after using your meds, or if the shaking seemed to come on when you started on a new prescription, your primary care provider should be able to offer an alternative drug that won’t make you shake. (Here are 6 medications that cause weight gain—and how you can fight back.)


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Yet another cause of enhanced physiologic tremor: fatigue.

Whether you’re tired due to a lack of sleep or because you completed a long, grueling workout, both muscle fatigue and exhaustion are associated with tremors of the hands and other body parts, research shows. Ditto anything that can mess with your sleep—like a night of heavy drinking.

MORE: 8 Diseases That Have Fatigue As The Main Symptom

But again, fatigue can also make essential tremor more pronounced, Jankovic says. So if your hands always shake—but it becomes really bad when you’re tired or sleep-deprived—that’s worth mentioning to your doctor.

Markham Heid Markham Heid is an experienced health reporter and writer, has contributed to outlets like TIME, Men’s Health, and Everyday Health, and has received reporting awards from the Society of Professional Journalists and the Maryland, Delaware, and D.C.

About tremor

Everyone has a small level of tremor – known as ‘physiological tremor’ – that caffeine, alcohol or stress can make more noticeable.

It’s not clear exactly how many people with MS are affected by tremor, although studies have suggested it’s between 25 and 60 per cent. If tremor is affecting your day-to-day life, you can speak to your GP or MS nurse. If you are already in contact with a physiotherapist or occupational therapist, you could also discuss it with them.

Tremor is one of the more difficult symptoms of MS to manage, but there are things that can make a difference. Rehabilitation involving physical or occupational therapy, drug treatments and, in some cases, surgery, have all been shown to help some people. There is no single approach that works for everyone, so you may have to try a number of different treatment options before you find what’s best for you. There are two kinds of tremor that are most common as a result of MS:

Intention tremor – most common in MS

Intention tremor comes on when you want to do something or reach for something. It often gets worse the closer you get to the object. This is the type of tremor people most often experience in MS.

Postural tremor

Postural tremor is when you shake when you are sitting or standing. It comes on while your muscles are trying to hold part of your body still against the forces of gravity.


You may come across the word ‘ataxia’ used instead of, or as well as, tremor. This is a medical term for a group of symptoms that includes problems with balance and coordination alongside tremor. Many people with MS experience ataxia, and the term is often used in relation to MS-related tremor.

In a prevalence cohort study by Pittock and colleagues, 200 MS patients living in Olmsted County, Minnesota, USA were assessed for tremor and measures of disability. Tremor was found in 25.5% and severe tremor in 3% of the study population . Probably the community based population in the latter study gives a more realistic estimate of tremor prevalence in MS. In both studies, however, tremor was associated with greater disability as measured on the expanded disability status scale (EDSS). In the Olmsted County population, patients with tremor of any severity were more likely to be unemployed or retired early because of disability.

Tremor subtypes

Tremor in MS can involve the head, neck, vocal cords, trunk and limbs, whereas involvement of the tongue, jaw or palate has not been reported .

The different types of tremor are currently classified according to a working consensus of the Movement Disorder Society . In MS, the two most prevalent tremor forms are postural tremor (tremor present whilst voluntarily maintaining a position against gravity) and intention tremor (tremor occurring during target directed movement where tremor amplitude increases during visually guided movements towards the target). True rest tremor (tremor present in a body part that is not voluntarily activated and is completely supported against gravity) is unusual in patients with MS, and Holmes (or “rubral”) tremor is also very uncommon.

In the two main prevalence studies, rest tremor was observed only in the Olmsted County survey (1% of patients), whereas Holmes tremor was observed in neither study. An overview of the affected body parts observed in both studies is given in Table 1. In both studies tremor was most commonly found in the arms. In the London study population, 36% of patients suffered from bilateral arm tremor, making this the most common pattern of limb involvement.

Table 1 Details of the two main prevalence studies on tremor in MS

Pathophysiology of tremor

The pathophysiology of tremor in MS is a difficult area of investigation, partly because MS is by definition a multifocal disease, so that tremor occurrence cannot easily be linked to a single neuroanatomical site. Systematic postmortem studies on the link between lesion site and the clinical phenomenon of tremor have never been undertaken.

The predominance of action tremors (postural and intention) in patients with MS point to the cerebellum and its connections as the most likely source of tremor production, whereas the rarity of rest tremor argues against an involvement of the basal ganglia. The common occurrence of bilateral tremor might indicate that damage to the cerebellum and its connections is often multifocal.

Another link to the cerebellum in the pathophysiology of tremor in MS is the effect of peripheral cooling on intention tremor. Intention tremor is thought to be modulated through increased long latency stretch reflexes . Cooling has been shown to decrease the sensitivity of muscle spindles and the velocity of peripheral nerve conduction . In two experimental studies, cooling of the arms markedly reduced intention tremor severity in patients with MS . The authors argue that this effect might have been partly due to decreased muscle spindle function and decreased nerve conduction velocity, which in turn resulted in decreased input into tremor producing cerebellar circuits.

Alusi and coworkers drew attention to the placement site of deep brain stimulation (DBS) electrodes to help understand the neuronal circuits involved in tremor production. They stated that neurosurgeons increasingly chose the nucleus ventralis oralis posterior (VOP) of the thalamus rather than the classic target, the nucleus ventralis intermedius (VIM). This is interesting because the VOP is the basal ganglia output nucleus of the thalamus , suggesting that the cerebellar tremors seen in MS might actually be generated by the basal ganglia. The standard electrode placement site reported in the literature, however, is the VIM and no studies comparing placement sites have been published. Whittle and coworkers comment on the difficulty of electrode placement in MS patients: in most patients there are major brain distortions due to demyelination, plaque formation and e vacuo hydrocephalus, and it is therefore uncertain whether the anatomy of these patients conforms to standard stereotactic atlasses . Keeping these comments in mind, it seems unwise to base pathophysiological theories purely on DBS electrode placement site.

A range of animal experiments have been undertaken to indentify the anatomical structures involved in tremor production (for review ). It has been shown that damage or removal of the cerebellar cortex does not induce intention tremor in monkeys, whereas partial or complete cerebellectomy leads to tremor during movement and posture . A slow, 3–5 Hz tremor during target directed movements can also be induced by reversible cooling of the dentate nucleus (the origin of most cerebellar efferents) in monkeys .

Most cerebellar efferents project from the dentate nucleus via the superior cerebellar peduncle (brachium conjunctivum) to the red nucleus and the thalamus. According to some studies, transection of the superior cerebellar peduncle causes intention tremor in monkeys , whereas other authors do not mention this effect.

Interestingly, Carpenter and colleagues report that tremor induced by transection of the superior cerebellar peduncle can be alleviated by a second lesion in the lateroventral or centromedian thalamus. The results of these animal studies suggest that damage to cerebellar efferents (through lesions of the dentate nucleus or superior cerebellar peduncle) may cause disinhibition of thalamic nuclei which are the main producers of intention tremor.

Although this is an interesting pathophysiologic model of intention tremor production, it remains uncertain whether the results of animal studies can be generalized to patients with MS.

In summary, clinical observation, animal studies and some experimental evidence in humans favour the cerebellum and the thalamic nuclei connected to it as the major locus of intention tremor production, but more research is needed to evaluate the role of the basal ganglia and other systems in tremor production in MS.

Assessment of tremor

Depending on the subtype of tremor, several methods for the assessment of tremor severity and its impact on the lives of patients have been developed. Rest tremor is often assessed with the tremor subscale of the Unified Parkinson’s Disease Rating Scale (UPDRS). Fahn and colleagues devised the most comprehensive tremor scale for non-parkinsonian tremor in 1984 . This instrument measures tremor in nine body parts at rest, while maintaining a posture and during goal directed movements. It also includes an assessment of arm tremor while writing and pouring water as well as a subscale for functional disability (interference of tremor with dressing, writing, eating etc.). Some studies included in this review use a modified and heavily abbreviated version of this scale, but most studies assess tremor by clinical examination only (e.g. by finger-to-nose testing, drinking from a cup, nine-hole-peg-test or writing and drawing tasks) or use a simple ordinal severity scale, often classifying tremor as absent, mild, moderate or severe. A simple 0–10 tremor severity scale devised by Bain and coworkers has been shown to be a valid and reliable measurement tool in patients with MS , but has so far only been used in few clinical studies .

Accelerometry and polarized light goniometry are neurophysiologic methods of tremor assessment. While these methods offer an objective measurement of tremor severity, they can only measure one aspect of an often complex movement problem at a time, and e.g. cannot measure the ataxia which often complicates tremor in MS.

Matsumoto and colleagues devised a more complex “quantitative movement analysis technique”, which records the patients’ goal directed movements in three dimensions using an electromagnetic tracking device, but the complexity of this method as well as the computer aided tracking tasks employed by Aisen and coworkers prohibit their widespread use.

One of the most important aspects of tremor in MS is its impact on the daily life of the patients. Functional status in MS-patients is often measured by asking the patients to complete questionnaires assessing activities of daily living such as writing, eating or dressing. Often these scales are self-devised and not validated. Validated scales used in the studies reviewed in this article include the Frenchay Activities Index and the quality of life subscale of the Functional Assessment of Multiple Sclerosis Scale (FAMS) .

Medical treatment

A summary of the published studies on medical treatment of tremor in MS is given in Table 2. Most of the published literature on medical treatment consists of case reports and uncontrolled open label studies. The few randomized controlled trials comprised small numbers of patients and very likely lacked the power to reveal small treatment effects.

Table 2 Studies on medical treatment of tremor in MS

Koller evaluated the effect of propranolol, isoniazid and ethanol on tremor in three tremulous MS patients in a double blind crossover trial and found no treatment effect for any of the treatments . To the best of our knowledge, no further trials with propranolol have been published, but it is interesting to note that Alusi and coworkers excluded two tremulous MS patients from a thalamotomy trial because they had achieved functional improvement after propranolol use .

In an open study the hypnotic-sedative drug glutethimide exhibited visible functional benefit in six of eight MS patients with tremor . Apparently, a controlled trial to confirm these findings was never undertaken.

Two double-blind placebo-controlled trials using isoniazid were published. In the first study reduction of tremor occurred in six of eight patients , with functional improvement in four patients. In the second study all six patients had measurable tremor reduction after treatment with isoniazid but this did not lead to functional improvement . Doses of isoniazid used to treat MS-related tremor were very high (up to 1200 mg a day), and treatment was in some patients associated with anorexia and nausea or with a combination of drowsiness, dysphagia and increased bronchial secretion. Other reported side effects were abnormal liver function tests, fatigue and increased weakness . Isoniazid inhibits GABA aminotransferase activity and increases GABA in the central nervous system, but no correlation was found between the degree of GABA elevation in the cerebrospinal fluid and clinical response .

Sechi and coworkers published a small single-blind placebo-controlled trial with carbamazepine . They reported improvement of tremor as assessed by clinical examination and accelerometry in all seven included patients, but failed to report whether this translated into functional improvement.

A placebo controlled, double-blind, crossover study, suggested that a single intravenous dose of the 5-HT3 receptor antagonist ondansetron led to tremor reduction in twelve, and to functional improvement in nine of the sixteen included tremulous MS patients . A subsequent open label study by Gbadamosi and colleagues which used the same intervention found no significant treatment effect . Likewise, a small clinical trial with dolasetron, another 5-HT3 receptor antagonist, showed no significant treatment effect on cerebellar ataxia .

Weiss and coworkers reported a positive effect of intrathecal baclofen in a single patient with bilateral arm tremor . The tremor amplitude decreased almost linearly as the dosage increased and tremor was abolished at a dosage of 250 µg per day. This possible treatment option has, however, not been observed or evaluated in other studies.

In recent years, there has been growing interest in cannabis as a possible therapeutic in MS. In the 1980’s a case report and a small uncontrolled study on the beneficial effects of cannabis on tremor and spasticity in MS were published and a survey taken among MS patients revealed that many patients experienced positive effects of smoked cannabis on MS-related symptoms .

Baker and colleagues reported a decrease of tremor and spasticity in an animal model of MS after treatment with Δ9-tetrahydrocannabinol, the active ingredient of cannabis . All this furthered hopes of cannabis as a possible new treatment option for tremor in MS, but much to the disappointment of tremulous MS patients, several well conducted randomized controlled trials did not show a significant effect of orally administered cannabis extracts or oral Δ9-tetrahydrocannabinol on tremor.

Surgical treatment

The surgical treatment options for tremor in MS are stereotactic thalamotomy and DBS. An overview of the published studies on surgical treatment is given in Tables 3 and 4. Most of the studies are small observational retrospective studies. When reviewing the literature on surgical treatment, it is surprising as well as disappointing that the majority of studies are remarkably imprecise in providing basic information on the length of follow-up, on adverse effects and-most importantly-on the effect on functional status and tremor associated disability.

Table 3 Studies on stereotactic surgery for the treatment of tremor in MS Table 4 Studies on DBS for the treatment of tremor in MS

The first study on thalamotomy for tremor in MS was published by Cooper in 1960 . Brice and colleagues were the first to report improvement of tremor through continuous thalamic DBS in 1980 .

Strategies for patient and treatment site selection

The earlier studies on thalamotomy used the thalamic nucleus ventralis lateralis (VL) as the target, whereas the nucleus VIM was chosen in most DBS studies and most later thalamotomy studies. This preference for the VIM is probably due to the experience with this thalamic nucleus in the treatment of tremor in Parkinson’s disease (PD) and essential tremor (ET). Research groups in Oxford and London used the nucleus VOP and the zona incerta (ZI) as targets for both lesional surgery and DBS, but the results yielded with these targets were not different from those reported for VIM or VL thalamotomy or stimulation.

The same researchers advocate the use of tremor frequency analysis during movement tasks as a method to identify patients likely to benefit from surgery . This may be a valuable tool for patient selection, although it has only been validated in a small number of patients and studies in which this technique is used do not report better results than studies without this selection method.

The site for lesional surgery or electrode placement is classically chosen relative to the site of the anterior and posterior commissures using a standardized atlas. More recently, surgeons tried to refine this placement strategy with microelectrode recording within the target area. Neurons discharging synchronous to peripheral tremor are identified and the treatment site is placed in an area where the most tremor related neuronal activity is found.

This method of treatment site selection is often used in studies on tremulous patients with PD and ET, but only a small number of MS-patients were included in these studies. Since this method offers a theoretical advantage over the classical methods of treatment site selection, it should be further evaluated.

Outcome after surgical treatment

Because of the many shortcomings of the published studies, the results need to be interpreted with great caution. It does, however, seem as if almost all patients experience tremor reduction immediately after thalamotomy, and roughly 70% of patients continue to benefit from thalamotomy beyond a follow-up period of one year (Table 3). In the three studies on thalamic DBS with a follow-up period longer than one year, 69% to 100% of the patients experienced reduced tremor . Functional improvement after both thalamotomy and DBS is much more variable and unfortunately not reported in many studies (Tables 3 and 4).

Niranjan published an interesting study on gamma-knife thalamotomy as a possible alternative to neurosurgery. In this study all three patients with MS-related tremor experienced marked improvement of tremor after radiosurgery. Unfortunately, no further studies have been published to evaluate this interesting non-invasive treatment option .

There are two trials in which thalamotomy and DBS were compared in patients with MS. In a randomized controlled trial conducted by Schuurman and colleagues patients with ET, tremor due to PD and tremulous MS patients were randomized to undergo either VIM thalamotomy or DBS. Five tremulous MS patients were randomized to each group. After a short follow-up period of six months, there were no significant differences between thalamotomy and DBS in functional outcome for the MS subgroup. In the same study, fewer adverse effects were observed in the DBS group, except for the subgroup of MS patients, where adverse effects were about equal for both interventions (Tables 3 and 4). Bittar and colleagues compared cumulative tremor scores for intention and postural tremor between patients undergoing VOP/ZI thalamotomy or DBS in a non-randomized study . Ten patients were in each group. Interestingly, after a mean follow-up period of 15 to 16 months, patients in the thalamotomy group had a better outcome (tremor reduction: 78% for postural tremor and 72% for intention tremor) than patients in the DBS group (tremor reduction: 64% for postural tremor and 36% for intention tremor). However, as there were more adverse effects in the thalamotomy group, no clear recommendations could be given.

Adverse events reported for the neurosurgical interventions comprised increase of hemiparesis, dysarthria, dysphasia, mental changes, depression, seizures, intracerebral haemorrhage, subdural haematoma, wound infection and MS relapse. Thalamotomy was associated with a higher risk of adverse events than DBS. Bilateral thalamotomy carries such a high risk of adverse effects, that it is no longer recommended. If bilateral treatment is necessary, either bilateral DBS or unilateral thalamotomy followed by contralateral DBS are possible treatment options.

Other treatment options

Electromagnetic fields, limb cooling, physiotherapy, weight bracelets, orthoses and specialized software have been advocated as additional treatment options.

Sandyk and Dann reported a reduction of intention as well as postural tremor in three tremulous MS patients treated with pulsed electromagnetic fields , but these interesting findings have not been substantiated in a larger trial.

Albrecht and coworkers published a small clinical trial on the effect of arm cooling on intention tremor . In their study, patients achieved significantly better results on a clinical testing battery after immersion of the tremulous arm in ice water. As this effect lasted for about 45 minutes the authors recommend limb cooling to achieve transient tremor control for activities such as working with a PC, signing a document or self-catherisation. In a similar study, Feys and colleagues report tremor reduction lasting for about 30 minutes after limb cooling with a special cooling device .

Weighted wrist cuffs are a mechanical tool to reduce tremor amplitude, and one article reported their beneficial effects in three MS patients . Although wearing bracelets decrease tremor amplitude and therefore may offer some benefit to tremulous patients, their effect on intention tremor is small and their use is therefore unlikely to yield important functional improvement. A more advanced computer aided tremor reducing orthosis provided functional benefit in a small case series including patients with MS .

Physiotherapy aimed at improving ataxia in MS was evaluated by Armutlu and coworkers. In their small pilot study they found that rehabilitative physiotherapy using Johnstone pressure splints was superior to physiotherapy alone . Unfortunately no larger trials followed this pilot study, so that it remains uncertain which patients may benefit from which form of physiotherapy.

The use of a mouse driven computer system is a special challenge for tremulous MS patients. Feys and colleagues published a study on the use of specialized software developed to aid computer use in 36 tremulous MS patients and found significant improvement in the time needed to complete some basic mouse driven computer operations .

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