Hemifacial spasm is a neurologic condition characterized by involuntary muscle contractions affecting one side of the face. The spasms usually begin around the eye and may gradually spread to involve other facial muscles, including the cheek and mouth.
These contractions are typically caused by irritation of the facial nerve (cranial nerve VII). The spasms may occur intermittently at first but can become more frequent or persistent over time.
Botulinum toxin injections are widely considered the first-line treatment for hemifacial spasm. The medication works by temporarily relaxing the overactive muscles responsible for the involuntary contractions. Carefully placed injections can significantly reduce twitching and improve comfort and facial symmetry.
Treatment is performed in the office and usually takes only a few minutes. Small amounts of medication are injected into specific muscles involved in the spasm pattern.
Most patients begin noticing improvement within 3–7 days, with the full effect developing over the following one to two weeks. The benefits typically last about 3–4 months, after which repeat treatment can maintain symptom control.
Because hemifacial spasm affects different muscles in each patient, injection patterns are tailored individually to target the muscles contributing most to the spasms.
Common Symptoms
Involuntary contractions of the cheek or mouth
Repetitive twitching of the eyelid
Facial pulling or tightening on one side
Increased spasms with fatigue or stress
Difficulty keeping the eye open due to spasms
Treatment Areas
Botulinum toxin injections may be placed in affected facial muscles such as:
Orbicularis oculi (around the eye)
Zygomatic muscles (cheek area)
Orbicularis oris (around the mouth)
Other involved facial muscles depending on the spasm pattern
Duration
Appointment time: ~10–15 minutes
Onset of improvement: 3–7 days
Duration of effect: ~3–4 months