From tension to disease: exploring the various causes of hand tremors

Author: Liu Xiangyi, deputy chief physician, Peking University Third Hospital

Reviewer: Fan Dongsheng, Chief Physician, Peking University Third Hospital

Hand tremor is a common symptom. There are many reasons that may cause hand tremor, such as tension, anxiety, fatigue, and side effects of drugs. In some cases, hand tremor may also be an early sign of a neurological disease, such as Parkinson's disease or essential tremor. Different reasons lead to different characteristics of hand tremor. We must identify the cause and treat it scientifically.

(1) Parkinson's disease

The hand tremor caused by Parkinson's disease is a resting tremor, which usually starts on one side. Its characteristics are that the limbs are at rest when the tremor occurs, and are not in a state of supporting against gravity; the resting tremor symptoms are mild or absent during activity and disappear during sleep; the tremor frequency is 3 to 6 times per second, and the tremor amplitude is not large. Most patients will experience "pill-rolling" tremors, which are specifically manifested as reciprocating relative movements of the thumb and index finger, like rolling a ball, hence the name. If a patient has unilateral hand tremors and then gradually develops tremors, stiffness, and bradykinesia in more limbs, you need to be alert to Parkinson's disease and should seek medical attention as soon as possible.

(2) Essential tremor

The hand tremor of essential tremor manifests as action tremor. At the onset, the frequency is relatively fast, 5 to 18 times per second, with a small amplitude; it gradually slows down to 4 to 8 times per second, with a large amplitude.

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Action tremor includes kinetic tremor and postural tremor. Kinetic tremor occurs at the last part of the movement toward the target and has a low amplitude, while postural tremor occurs when the limbs are in a specific posture or perform a specific task (such as writing, etc.), usually starting in both hands. The typical symptoms are rhythmic abduction, adduction and flexion-extension tremors of the hands. Pronation and supination tremors are very rare.

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The onset age of essential tremor can range from adolescence to middle-aged and elderly people, and it usually progresses slowly. In the early stages of the disease, patients can control it themselves through psychological adjustments. Most patients with essential tremor have mild symptoms, and only about 1/10 of them require treatment. About 50% of them can control their symptoms well with medication, while the rest are insensitive to medication and require botulinum toxin injections or stereotactic radiotherapy.

Dystonia

Hand tremors in dystonia often occur in patients with localized and hemiplegic tremors. Tremors in patients with dystonia can be either static or action tremors. Tremor is not a prominent symptom in patients with dystonia, and the incidence is not high. If a patient has tremor accompanied by abnormal limb posture or dancing, he or she should seek medical treatment as soon as possible and strengthen clinical care, which is of great significance to improving the quality of life.

Cerebellar lesions

Hand tremors caused by cerebellar lesions are usually action tremors, which are one of the manifestations of cerebellar damage. Patients with cerebellar damage have impaired voluntary movements, manifested as excessive or insufficient movement, fatigue, directional deviation, loss of movement stability, especially the start, stop and change of direction of movement are affected, manifested as "ataxic tremor". For example, in the finger-to-nose test, when a finger is pointed to the nose or the patient moves his finger from the tip of the nose to touch the examiner's finger, there is an obvious deviation and tremor, which is also called "intention tremor". Patients with cerebellar lesions may also have balance disorders, ataxia, nystagmus and dysarthria, etc. It is recommended to seek medical treatment as soon as possible.

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Many people think that hand tremors are a normal phenomenon that occurs with aging, and basically do not seek medical treatment. However, if the hand tremors are related to specific times, forms, postures or tasks, and the hand tremors gradually become more severe or spread to a wider range, you should seek medical treatment as soon as possible.