From the Guidelines
Tremors are primarily caused by neurodegenerative diseases, such as Parkinson's disease, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration, as well as other conditions like essential tremor, physiologic tremor, and drug-induced or metabolic tremors. When evaluating a patient with tremors, it is essential to consider the clinical presentation, including the type of tremor (resting, postural, or action), associated symptoms, and medical history. The diagnostic approach should involve a combination of clinical evaluation and targeted testing, including blood work, toxicology screening, and sometimes brain imaging, as recommended by the American College of Radiology 1. Common causes of tremors include:
- Essential tremor, often familial with postural and action tremors
- Parkinson's disease, characterized by resting tremor
- Physiologic tremor, exacerbated by caffeine, anxiety, or medications
- Cerebellar tremor, intention tremor with past pointing
- Drug-induced or metabolic tremors, which can be caused by various medications or underlying medical conditions, such as hepatic encephalopathy 1
- Parkinsonian syndromes, including multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration, which can present with tremors, rigidity, and bradykinesia 1. Accurate diagnosis is crucial, as treatment approaches vary significantly depending on the underlying cause, from beta-blockers for essential tremor to dopaminergic medications for Parkinsonian tremor. In some cases, tremors can be a side effect of medications, such as antidopaminergic agents, which can induce symptoms of Parkinson's disease, including bradykinesia, tremors, and rigidity 1. A thorough medical history, physical examination, and targeted testing are necessary to determine the underlying cause of tremors and guide appropriate treatment.
From the Research
Causes of Tremors
The causes of tremors are heterogeneous and can be classified based on several clinical characteristics, including anatomical pattern, tremor frequency, and tremor amplitude 2, 3. Some of the common causes of tremors include:
- Physiological tremor
- Essential tremor
- Drug-induced tremor
- Dystonic tremor
- Psychogenic tremor
- Metabolic tremor caused by thyrotoxicosis
- Wilson's disease
- Fragile X-associated tremor/ataxia syndrome
- Parkinson's disease
Classification of Tremors
Tremors can be classified into different types based on their clinical characteristics, such as:
- Resting tremor, which is often associated with Parkinson's disease 2
- Postural tremor, which can be caused by physiological tremor, essential tremor, or drug-induced tremor 2, 3
- Intention tremor, which can be a symptom of multiple sclerosis or other neurological disorders 3
Diagnosis and Treatment
The diagnosis of tremors is mainly clinical, based on a detailed history and physical examination 2, 3. In some cases, additional tests such as blood examinations or imaging studies may be necessary to determine the underlying cause of the tremor. Treatment options vary depending on the cause of the tremor, and may include pharmacotherapy, physical therapy, or other interventions 4.