What is facial muscle spasm?

Hemifacial spasm, also known as facial muscle twitching, is a condition characterized by paroxysmal, involuntary twitching of the facial muscles on one or both sides, including the orbicularis oculi, facial expression muscles, and orbicularis oris. This condition usually affects the orbicularis oculi muscle, causing frequent blinking, and may subsequently spread to other facial muscles such as those around the mouth, resulting in facial twitching or distortion. The pathogenesis of hemifacial spasm is associated with vascular compression of the facial nerve. Long-term vascular compression can lead to abnormal neural discharges, thereby causing involuntary contractions of the facial muscles.

Hemifacial spasm typically occurs in middle-aged and elderly individuals, with a slightly higher prevalence among women than men. However, in recent years, there has been a trend toward younger onset. The causes can be classified as either primary or secondary. The exact cause of primary hemifacial spasm remains unclear, but it may be related to some form of irritation or compression affecting the facial nerve. Secondary hemifacial spasm is often caused by sequelae of facial paralysis or other neurological disorders.

In the early stages, hemifacial spasm may manifest only as mild eyelid twitching. Symptoms often worsen during fatigue, mental stress, or specific facial movements. As the condition progresses, the range and frequency of twitching increase, significantly impacting the patient's quality of life, including social interactions, work, and sleep. Additionally, persistent facial twitching may lead to ocular discomfort, such as dryness and photophobia.

In terms of treatment, management options for hemifacial spasm include pharmacological therapy, botulinum toxin injections, and surgical intervention.