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.
Rezzy AI Tutor

Have doubts about this lesson?

Ask Rezzy, our AI tutor, to explain anything you didn't understand

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 For Free
Blepharospasm and Hemifacial Spasm - Free Indian Medical PG