Blepharospasm and Hemifacial Spasm

Blepharospasm and Hemifacial Spasm

Blepharospasm and Hemifacial Spasm

On this page

Overview & Definitions - Twitchy Twins Intro

  • Blepharospasm (Benign Essential Blepharospasm - BEB): Involuntary, bilateral, repetitive, forceful eyelid closure. A focal dystonia affecting orbicularis oculi.
  • Hemifacial Spasm (HFS): Unilateral, intermittent, involuntary contractions of muscles innervated by CN VII (facial nerve), typically starting around the eye.
  • Primary Cause Distinction:
    • BEB: Mostly idiopathic; rarely secondary to drugs (e.g., neuroleptics) or basal ganglia lesions.
    • HFS: Often vascular compression of facial nerve root exit zone; less commonly tumors or post-Bell's palsy. Facial muscles and injection points for blepharospasm

⭐ Blepharospasm typically bilateral, HFS unilateral.

Essential Blepharospasm (BEB) - Squeezy Eye Saga

  • Bilateral, involuntary, progressive, spasmodic eyelid closure; idiopathic focal dystonia.
  • Onset: Typically 50-70 years, F > M.
  • Symptoms: ↑ blinking → forceful spasms, photophobia, difficulty keeping eyes open; can lead to functional blindness.
    • Aggravated by: Bright light, stress, fatigue.
    • Relieved by: Sleep, relaxation, sensory tricks (geste antagoniste).
  • 📌 BEB: Bilateral Eyelid spasms, Botox is best.

⭐ Associated with Meige syndrome (oromandibular dystonia + blepharospasm).

  • Treatment:
    • 1st line: Botulinum toxin A injections (orbicularis oculi, procerus, corrugator) q 3-4 months.
    • 2nd line: Surgical (limited myectomy) if botox fails.

Hemifacial Spasm (HFS) - One-Sided Winks

  • Unilateral, involuntary, intermittent contractions (clonic/tonic) of facial nerve (CN VII) muscles.
  • Etiology:
    • Primary (Idiopathic): Most common.

      ⭐ Most common cause: vascular compression of CN VII root exit zone (REZ) by aberrant vessel (AICA, PICA).

    • Secondary: Post-facial palsy, CPA tumors, MS, trauma.
  • Clinical Features:
    • Starts orbicularis oculi, spreads ipsilaterally.
    • "Other Babinski sign": Eyebrow lift with forced eye closure.
    • Persists during sleep. Hemifacial Spasm vs. Blepharospasm
  • Investigations:
    • MRI Brain/Brainstem: Rule out secondary causes.
  • Treatment:
    • Botulinum toxin A injections (first-line).
    • Medical: Carbamazepine, gabapentin (less effective).
    • Surgical: Microvascular Decompression (MVD) if refractory_cases_with_identified_vascular_loop_

Differentiating Spasms - Twitch Tell-Tale

FeatureEssential Blepharospasm (BEB)Hemifacial Spasm (HFS)
LateralityTypically bilateral, symmetric onsetStrictly unilateral
Muscles InvolvedOrbicularis oculi; may spread (Meige's)Muscles innervated by CN VII (one side)
During SleepSpasms usually ceaseSpasms often persist
Common EtiologyOften idiopathic; drug-induced; dystoniaVascular compression (CN VII root); post-Bell's
Other Facial AreasMay involve lower face/neck (Meige's)Progresses: eye → cheek → mouth → neck

Treatment Toolkit - Taming The Twitches

⭐ Botulinum toxin A is the first-line treatment for both BEB and symptomatic HFS.

  • Botulinum Toxin A (BoNT-A):
    • Gold standard; inhibits acetylcholine release.
    • Repeated injections every 3-4 months.
    • Target muscles: Orbicularis oculi, procerus, corrugator.
  • Supportive Measures: Dark glasses, FL-41 tinted lenses, stress reduction.
  • Surgical Options (for refractory cases):
    • BEB: Limited myectomy or frontalis suspension.
    • HFS: Microvascular Decompression (MVD) of facial nerve.

Botulinum toxin injection sites for periocular spasms

High‑Yield Points - ⚡ Biggest Takeaways

  • Blepharospasm: Bilateral, involuntary orbicularis oculi spasms; can cause functional blindness. Botulinum toxin (BoNT-A) is first-line.
  • Hemifacial Spasm: Unilateral facial muscle (CN VII) twitching; often from vascular compression of the facial nerve.
  • Key differentiator: Hemifacial Spasm persists during sleep.
  • BoNT-A is the primary treatment for both; Microvascular Decompression (MVD) is curative for Hemifacial Spasm.
  • Meige Syndrome: Blepharospasm combined with oromandibular dystonia.

Practice Questions: Blepharospasm and Hemifacial Spasm

Test your understanding with these related questions

Most common cause of facial nerve palsy:

1 of 5

Flashcards: Blepharospasm and Hemifacial Spasm

1/10

_____ is characterized by the inability to close the eyelids voluntarily.

TAP TO REVEAL ANSWER

_____ is characterized by the inability to close the eyelids voluntarily.

Lagophthalmos

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial