Hemifacial spasm results from vascular compression of the facial nerve (the seventh nerve). Trigeminal neuralgia results from vascular compression of the trigeminal nerve (the fifth nerve). Hemifacial spasm usually begins with intermittent twitching around the eye on one side of the face. Over time the twitching spreads to involve the rest of the face. It is usually painless.
Medications are usually not effective. Many patients get botox injections every 3-4 months to control. A more permanent cure can be provided by the same microvascular decompression operation used for trigeminal neuralgia. But in this disease its usually a different artery and, of course, its a different nerve (the facial nerve). The operation typically takes about an hour. Most patients spend two nights in the hospital and a couple of weeks at home recuperating before resuming full normal activities.
Surgery is very safe but, as in all operations, there is a small chance of a complication. Potential complications include failure to relieve spasm, hearing loss, infection, bleeding, CSF leak, hydrocephalus, and others.