Essential Tremor: Causes, Symptoms & Who Is Affected

Essential Tremor (ET) Overview

Most common movement disorder; prevalence ~1% overall, ~5% over age 65. Onset typically 40–60 yrs (bimodal: young adult & older), but can begin in childhood. Slight male predominance. 50–70% familial (autosomal dominant with variable penetrance).

Pathophysiology

Oscillatory activity in cerebello-thalamo-cortical circuit; GABAergic dysfunction in cerebellum (Purkinje cell loss). Not Lewy body / dopaminergic (distinct from Parkinson's).

Clinical Features

• Action tremor – Postural (holding against gravity) + kinetic (voluntary movement). Absent at rest (vs. PD).
• Distribution: Hands (95%), head (30% – "yes-yes" or "no-no"), voice (quiver), jaw, tongue, legs (rare).
• Progression: Slow; amplitude increases, frequency decreases (8–12 Hz → 4–8 Hz).
• Functional impact: Writing, eating, drinking, typing, grooming, speaking.
• Non-motor: Anxiety, depression, social embarrassment, cognitive changes (mild).

Diagnosis

• Clinical (history + exam); no biomarker.
• Rule out: enhanced physiologic tremor (caffeine, meds, hyperthyroidism), PD (rest tremor, bradykinesia), dystonia, cerebellar disease, drug-induced.
• DaTscan if uncertain.

Treatment

1. First-line: Propranolol (beta-blocker) 60–240 mg/day OR Primidone 50–750 mg/day. ~50% respond.
2. Second-line: Topiramate, gabapentin, zonisamide, alprazolam (short-term).
3. Botulinum toxin – For head/voice tremor.
4. DBS (VIM thalamus) – Medication-refractory, disabling; >80% tremor reduction.
5. Focused ultrasound thalamotomy – Non-invasive alternative to DBS.
6. Lifestyle: Limit caffeine, alcohol, stress; weighted utensils, adaptive devices.

ET is chronic but manageable; multidisciplinary care (neurology, OT, PT, psychology) optimizes quality of life.