Differential Diagnosis for Unilateral Arm Tremor
Single Most Likely Diagnosis
- Essential Tremor: This is the most common cause of tremors, and unilateral arm tremor can be an early manifestation. It is characterized by a postural or action tremor, and it can be inherited in some cases.
Other Likely Diagnoses
- Parkinson's Disease: Although Parkinson's disease typically presents with bilateral symptoms, it can start unilaterally. A unilateral arm tremor, especially if it is a resting tremor, should prompt consideration of Parkinson's disease.
- Dystonic Tremor: This type of tremor is associated with dystonia, a movement disorder characterized by involuntary muscle contractions. Dystonic tremor can be unilateral and is often accompanied by other dystonic symptoms.
- Cerebellar Tremor: A unilateral cerebellar tremor can occur due to lesions in the cerebellum, such as stroke or tumor. It is typically an intention tremor, worsening as the hand approaches a target.
Do Not Miss Diagnoses
- Stroke or Transient Ischemic Attack (TIA): A sudden-onset unilateral arm tremor could be a sign of a stroke or TIA, especially if accompanied by other symptoms like weakness, numbness, or speech changes.
- Brain Tumor: A unilateral arm tremor could be a symptom of a brain tumor, particularly if it is located in the motor cortex, basal ganglia, or cerebellum.
- Multiple Sclerosis: Tremor can be a symptom of multiple sclerosis, especially during an acute relapse. It is essential to consider this diagnosis, especially in young adults with unilateral tremor and other neurological symptoms.
Rare Diagnoses
- Wilson's Disease: This is a rare genetic disorder that can cause tremors, among other symptoms like liver disease and psychiatric problems. It typically presents in young adults.
- Neurodegenerative Disorders (e.g., Multiple System Atrophy, Progressive Supranuclear Palsy): These rare disorders can cause tremors, among other symptoms like parkinsonism, ataxia, and autonomic dysfunction.
- Vascular Malformations or Arteriovenous Malformations (AVMs): Rarely, a unilateral arm tremor can be caused by a vascular malformation or AVM in the brain, which can cause focal neurological symptoms.