Tremor

Summary

• Tremor is a rhythmic, involuntary muscular contraction characterised by oscillations (to-and-fro movements) of a part of the body.  
• Tremor can affect various body parts such as the hands, head, facial structures, vocal cords, trunk and legs.
• Tremor often accompanies neurological disorders associated with aging.  
• The appropriate treatment depends on accurate diagnosis of the cause. 

Definition

Tremor is a rhythmic, involuntary muscular contraction characterised by oscillations (to-and-fro movements) of a part of the body. The most common of all involuntary movements, tremor can affect various body parts such as the hands, head, facial structures, vocal cords, trunk and legs. Most tremors, however, occur in the hands.

Tremor often accompanies neurological disorders associated with ageing. Although the disorder is not life-threatening, it can be responsible for functional disability and social embarrassment.

Types of Tremors

There are many types of tremor and several ways in which tremor is classified.

Resting or static tremor occurs when the muscle is at rest, for example when the hands are lying on the lap. This type of tremor is often seen in patients with Parkinson's disease.

Postural tremor occurs when a patient attempts to maintain posture, such as holding the hands outstretched. Postural tremors include physiological tremor, essential tremor, tremor with peripheral neuropathy, post-traumatic tremor and alcoholic tremor.

Action or intention tremor occurs during purposeful movement, for example during finger-to-nose testing, and may be seen in cerebellar disease. Task-specific tremor appears when performing goal-oriented tasks such as handwriting, speaking or standing.

This group consists of primary writing tremor, vocal tremor and orthostatic tremor. Hysterical tremor (also called psychogenic tremor) may disappear when the patient is distracted.

Treatment

There are some treatment options available for tremor. The appropriate treatment depends on accurate diagnosis of the cause. Some tremors respond to treatment of the underlying condition. For example in some cases of hysterical tremor treating the patient's underlying mental problem may cause the tremor to disappear. Also, patients with tremor due to Parkinson's disease may be treated with Levodopa drug therapy.

Symptomatic medication therapy is available for several other tremors as well. For those cases of tremor in which there is no effective drug treatment, physical measures such as teaching the patient to brace the affected limb during the tremor are sometimes useful. Surgical intervention such as thalamotomy may be useful in certain cases.

Reviewed by Dr Andrew Rose-Innes, MD, Department of Neurology, Yale University School of Medicine, New Haven.