Hemifacial spasm, also known as facial muscle twitching, is an involuntary clonic jerk on one side of the face. It is common in idiopathic cases, and can also be the sequelae of facial neuritis. 1, etiology may be related to mechanical stimulation or compression of the facial nerve pathway, some patients were found to be compressed by microvascular collaterals at the facial nerve out of the brainstem on exploration of the posterior cranial fossa, and decompression surgery can be cured, and a small number of patients were caused by tumors of cerebral bridges and cerebellar horns or vertebral artery aneurysms. Clinical manifestations Most of the cases develop after middle age, with more females, and most of them are one-sided. At the beginning, the orbicularis oculi muscle has intermittent slight twitching, which gradually spreads to the angle of the mouth and facial muscles on the same side, and in severe cases, it may involve the cervical vastus muscle, each time for a few seconds to a few minutes, and the twitching may be aggravated by mental tension, fatigue and voluntary movement. There are no positive neurological signs on examination. 3.Treatment 1) Botulinum toxin type A (BotulinumtoxintypeA, BTX) is the current treatment of choice, injection of a very small amount of BTX can be eliminated muscle spasm, the efficacy of the treatment lasts for 3 to 6 months, repeated injections are still effective after relapse. After injection, there may be transient facial muscle paralysis such as upper face drooping, which will subside after a few days; premature labor may occur during pregnancy. (2) Carbamazepine 0.1g, 2 to 3 times a day, gradually increased to 0.6g/d; phenytoin sodium 0.1 to 0.2g, 3 times a day, mild symptoms can be improved. 3) 50% alcohol or vitamin B12 facial nerve branch block. Microvascular decompression of the posterior cranial fossa can be effective, but may cause facial paralysis and may recur.