Essential Tremor

✅ Essential Tremor (ET) – one of the most common movement disorders, often inherited in an autosomal dominant pattern. It is benign in terms of survival 🕊️ but can be socially and functionally disabling. 👉 Many patients worry about Parkinson’s Disease (PD), so accurate differentiation is crucial.

🧑‍⚕️ Clinical Features

• Presentation: Gradual onset of 4–12 Hz postural/action tremor, typically hands & forearms. ✋
• Head Tremor (Titubation): "Yes–yes" or "no–no" rhythmic nodding; may affect the voice 🎤.
• Voice Tremor: Quavering, shaky voice quality.
• Leg Tremor: Rare but possible.
• Cogwheeling: May be present, without true rigidity.
• Course: Symmetrical, slow progression over years; gait usually normal.

🔍 Differentiation from Parkinson’s Disease (PD)

• ⏳ ET: Postural/action tremor; usually bilateral, improves with alcohol 🍷. PD: Resting tremor ("pill-rolling"), asymmetrical, no alcohol benefit.
• 🚶 ET: Normal gait & no bradykinesia. PD: Bradykinesia, shuffling gait, reduced arm swing.
• 🧾 ET: Family history common (autosomal dominant). PD: Usually sporadic, some genetic forms.
• 👀 Head/voice tremor: Common in ET, rare in PD.

🧪 Investigations

• Clinical Diagnosis: Largely bedside.
• 18F-FDOPA PET: ET = normal striatal uptake; PD = reduced uptake. 🎯
• Thyroid Function Tests (TFTs): Exclude hyperthyroidism.
• Wilson’s Disease Screening: <40 yrs with tremor → caeruloplasmin, serum & urine copper 🧪.

📋 Differential Diagnosis

• Anxiety & Stress Tremor: Situational, transient.
• Parkinson’s Disease: Rest tremor, rigidity, bradykinesia.
• Wilson’s Disease: Young patients, "wing-beating" tremor + other neuro signs.

💊 Management

• Reassurance: Many patients relieved once PD excluded. 🧾
• Lifestyle: Reduce caffeine, stress; small alcohol intake may transiently improve tremor (not long-term therapy).
• Medications:
  • 🫀 Propranolol (β-blocker): First-line; reduces tremor amplitude.
  • 💊 Primidone (anticonvulsant): Useful if propranolol not tolerated.
  • 😊 Mirtazapine: Consider if anxiety/depression co-exist.
• Advanced therapy: Severe/refractory cases → stereotactic thalamotomy or DBS of VIM ⚡

💡 Exam Pearls

• ET = action tremor, symmetrical, family history, improves with alcohol. • PD = resting tremor, asymmetrical, bradykinesia, rigidity, no alcohol benefit. • Severe ET → consider DBS of VIM nucleus of thalamus.

📚 References & NICE Guidance

• ✅ NINDS – Essential Tremor Overview
• ✅ BMJ JNNP – Essential Tremor Review
• ✅ NICE Guideline NG71 – Parkinson’s Disease: Diagnosis and Management (helps differentiate ET from PD clinically)
• ✅ NCBI Bookshelf – Movement Disorders: Essential Tremor