Hemifacial spasm is a condition where muscles on one side of the face contract involuntarily, causing intermittent twitching or sustained spasms. It often begins around the eye and can spread to the cheek, mouth, and neck on the same side.
Causes and Features
The most common cause is blood vessel contact with the facial nerve at its exit from the brainstem, leading to abnormal nerve firing. Spasms can be triggered or worsened by stress, fatigue, or voluntary facial movements and may persist during sleep in some individuals.
- Typically unilateral, involving only one side of the face
- Episodes may start as brief twitches and progress to more forceful contractions
- There is usually no weakness between spasms
- Hearing changes or facial tightness can sometimes accompany symptoms
Management
Diagnosis is based on clinical examination and sometimes imaging to look for vascular compression or other structural causes. Botulinum toxin injections into affected muscles are commonly used to reduce spasm, and microvascular decompression surgery may be considered in selected cases.
- Imaging such as MRI can help exclude tumours or other rare causes
- Botulinum toxin provides temporary relief but needs repeating periodically
- Surgical decompression aims to separate the offending blood vessel from the nerve
- Regular follow-up allows adjustment of treatment according to symptom severity
