Tremors are unintentional trembling or shaking movements. Most tremors occur in the hands, but you can also have arm, head, face, vocal cord, trunk and leg tremors. Although most common in middle-aged and older people, anyone can have tremors.
Tremors may not be a sign of other neurological problems, as they commonly occur in otherwise healthy people. Sometimes, however, diseases such as Parkinson's disease, multiple sclerosis, stroke or certain medicines can cause them. Some forms of tremors are genetic, while others are due to other medical conditions or even medications.
Tremors are not life threatening. Some people find them embarrassing, however, and they can make it hard to perform daily tasks.
There are a number of different categories of tremor, including:
- Essential tremor, the most common tremor, can appear at any age. The hands are most often affected but the head and voice may also be frequently involved. Heightened emotion, stress, other illness, physical exhaustion or low blood sugar may temporarily worsen tremors. Essential Tremor is considered “benign” and may not need to be treated.
- Parkinsonian tremor is caused by damage to structures within the brain that control movement and is often the first symptom of Parkinson’s disease. This tremor appears characteristically as a resting tremor and can be markedly increased by stress or emotions. Movement starts in one limb or on one side of the body and usually progresses to include the other side. Jaw or leg tremor can be a common initial site as well.
- Cerebellar tremor is a more chaotic tremor of the extremities that occurs at the end of a purposeful movement, such as trying to press a button or touching a finger to the tip of one’s nose, incoordination accompanies it. Lesions or damage to the cerebellum on one side of the brain (resulting from stroke, tumor or disease such as multiple sclerosis) produce a tremor and incoordination in that same side of the body that worsens with directed movement. Cerebellar tremor may be accompanied by speech problems, nystagmus (rapid involuntary movements of the eyes) and gait incoordination as well.
- Orthostatic tremor involves rhythmic muscle contractions that occur in the legs and trunk immediately after standing. The person typically perceives that he/she is unsteady or describes leg discomfort rather than experiencing an actual tremor. No other clinical signs or symptoms are present and the unsteadiness ceases when the person sits or starts walking.
Tremor can result from other conditions as well, and so being evaluated by a Movement Disorders Neurologist is recommended.
During a physical and neurological exam a doctor will check whether the tremor occurs primarily during action or at rest, as well as for tremor symmetry, speed and quality. Additional associated features will be evaluated as well. The physician will take a detailed family history to determine if the tremor is inherited. In some cases, blood or urine tests can detect other metabolic causes of tremor. These tests may also help to identify contributing causes, such as drug interaction, or another condition or disease.
Diagnostic imaging using computerized tomography or magnetic resonance imaging may help determine if there is a lesion or other damage in the brain causing the tremor.
There is no cure for most tremors, but there may be treatment to relieve them. This treatment depends on their cause. Medicines and some surgical procedures, such as DBS, can reduce or stop tremors and improve muscle control, but the appropriate treatment depends on accurate diagnosis of the cause.
Diet and physical therapy may also help as well. For example, eliminating tremor “triggers,” such as caffeine or stress, is often recommended. Furthermore, physical therapy may help to reduce tremor and improve coordination and muscle control for some individuals.