Hand Tremor

Understanding essential tremor, parkinsonian tremor, and seizure-related tremor with clinical clues to differentiate them.

Topic: Movement disorders Level: Intermediate Tags: essential tremor, parkinsonism, seizure, movement

Overview

Hand tremor is an involuntary rhythmic oscillation caused by alternating or synchronous muscle contractions. It is among the most frequent movement-related complaints in neurology and spans benign, degenerative, and epileptic causes. Key diagnostic steps include defining the tremor’s activation condition (rest, posture, action), frequency, and associated neurologic signs.

Clinician tip: Observe the tremor at rest, with posture, and during action. The pattern often points directly to the underlying etiology.

Core features

  • Essential tremor: bilateral, postural/kinetic, often familial, alcohol responsive.
  • Parkinsonian tremor: rest predominant, 4–6 Hz, unilateral onset, pill-rolling character, accompanied by bradykinesia/rigidity.
  • Seizure-related tremor: paroxysmal, brief, may include Jacksonian march or impaired awareness, EEG correlates.

Subtypes / related entities

Essential Tremor

Most common pathologic tremor; symmetric postural/action tremor of the hands; improved with propranolol, primidone, or DBS if severe.

Parkinsonian Tremor

Rest tremor with asymmetric onset, reduced arm swing, and response to dopaminergic therapy (levodopa).

Key differences at a glance

Feature Essential Tremor Parkinsonian Tremor Seizure-related
Activation Posture/action Rest (may re-emerge with posture) Brief, paroxysmal, during seizure
Other signs None Bradykinesia, rigidity Possible impaired awareness, EEG changes

Work-up snapshot

  • History: onset, progression, family history, medication use, alcohol effect.
  • Exam: rest vs postural vs action tremor; rigidity, bradykinesia, or focal deficits.
  • Ancillary tests: thyroid and metabolic labs if indicated; brain imaging for atypical features; EEG if seizure suspected.
Red flag: Sudden-onset focal jerking with postictal weakness suggests cortical seizure and mandates EEG and urgent neurology input.

Treatment snapshot

  • Essential tremor: propranolol, primidone; deep brain stimulation for severe cases.
  • Parkinson’s disease: dopaminergic therapy (levodopa), lifestyle/rehab measures.
  • Seizure-related: antiepileptic drugs such as levetiracetam or carbamazepine tailored to seizure type.
Pearl: Alcohol responsiveness is a classic but subtle clinical clue to essential tremor.

References

  1. Bhatia KP et al. Movement Disorders Society consensus on tremor. Mov Disord. 2018.
  2. Postuma RB et al. MDS clinical diagnostic criteria for Parkinson’s disease. Mov Disord. 2015.
  3. Fisher RS et al. ILAE classification of seizures. Epilepsia. 2017.

Educational discussion. Not a substitute for clinical judgment. Consider local protocols and individual factors.