- a shaky voice
- a rhythmic shaking affecting the arms and hands, and less commonly the legs, head, and torso
- difficulty holding or controlling a pen, spoon, or other tool or utensil
A 2012 review estimates that tremor affects between 25 to 50 percent of people with MS. Severe tremors may affect up to 15 percent of people with MS.
For people with MS, tremors are usually caused by brain lesions (specifically in the cerebellum) and damaged areas — called plaques — along the nerve pathways that are involved with coordinating movement.
The same plaques sometimes also result in other symptoms such as dysphagia (difficulty swallowing) or dysarthria (difficulty speaking).
There are two primary types of tremor: resting and action.
Resting tremor occurs when there is shaking even when a body part is at rest. For example, a person may be sitting comfortably with their hands resting in their lap, but their fingers shake.
Action tremor occurs when a muscle is being voluntarily moved. For example, a person may be reaching to pick up a glass of water and their hand starts to shake.
There are a number of subclassifications of action tremor, including:
- Intention tremor. These are associated with physical movement. There is no shaking when a person is at rest, but a tremor develops and becomes more pronounced as they attempt to make a precise movement such as shifting a foot or hand to a specific spot.
- Postural tremor. These are associated with moving or supporting against gravity, such as a tremor that develops while standing or sitting, but not while lying down.
- Nystagmus. These tremors are associated with jumpy eye movements.
For people with MS, the most common forms of tremor are intention tremor and postural tremor.
Currently, there is no cure for tremors. But there are ways for people with MS to reduce their occurrence and improve function.
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)
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.
The MS tremors that develop for some people can be mild or, for up to 15 percent of those with MS, severe and disabling.
While there is no cure for tremors yet, people with MS have ways to reduce the occurrence of tremors and improve function including physical and occupational therapy, medication, and lifestyle changes.