Facial spasm

Hemifacial Spasm (HFS), also known as facial tic, manifests as involuntary twitching on one side of the face. The twitching is paroxysmal and irregular, with varying severity, and may be aggravated by fatigue, emotional stress, and voluntary movements. The onset typically begins in the orbicularis oculi muscle and then involves the entire face. This condition usually occurs after middle age and is more common in females. Because the early symptom of hemifacial spasm is eyelid twitching, there is a folk saying "left eye twitching brings wealth, right eye twitching brings disaster," so it generally does not attract people's attention. After a period of time, it develops into hemifacial spasm, spreading to the corner of the mouth, and in severe cases, involving the neck. Hemifacial spasm can be divided into two types: primary hemifacial spasm and secondary hemifacial spasm, which is hemifacial spasm resulting from sequelae of facial paralysis. The two types can be distinguished by their symptoms. Primary hemifacial spasm can occur even in a resting state, with spasms resolving after a few minutes and being uncontrollable; hemifacial spasm caused by sequelae of facial paralysis only occurs during actions such as blinking or raising the eyebrows. Hemifacial spasm is a functional disorder syndrome caused by irritation of the facial nerve on one side. It is usually unilateral; bilateral involvement is rare, accounting for about 4%. Most patients are adults over 40 years old, with an incidence rate of approximately 64 per 100,000 in the population. Stocks once reported 13 affected individuals across four generations of one family, but it is not a hereditary disease. This condition was already recorded in the early 16th century in the Chinese medical text "Shen Shi Yao Han" (Examination of the Mysterious and the Obscure). However, due to its unclear etiology and pathology, it was long regarded as an incurable disease and was rarely discussed in otology. It was only in the past 20 years, with the widespread development of neuro-otological surgery, that in-depth research on this disease was conducted, making it an important disease in otology.