hemifacial spasm Facial spasm (FS), mainly characterized by paroxysmal involuntary twitching of the muscles on one side of the face, mostly localized to one side, hence also known as hemifacial spasm (HFS), is a common slowly progressive peripheral nerve disorder. The symptoms worsen during emotional excitement or tension, but there are no other neurological abnormalities on physical examination.

Facial spasm (FS), characterized mainly by paroxysmal involuntary twitching of facial muscles on one side, mostly localized unilaterally, also known as hemifacial spasm (HFS), is a common slowly progressive peripheral nerve disorder. Symptoms tend to worsen during emotional excitement or tension, but physical examination reveals no other neurological abnormalities. Although this condition is benign, it significantly impacts the daily life and social interactions of patients, leading to anxiety and depression in some cases, thus requiring timely diagnosis and treatment.

Vascular Compression

This mainly involves compression of the facial nerve root by neighboring arteries such as the anterior inferior cerebellar artery, posterior inferior cerebellar artery, vertebral artery, basilar artery, or large venous structures. This accounts for approximately 80% to 90% of cases.

Space-Occupying Lesions

Tumors, cysts, or granulomas in the cerebellopontine angle can also lead to facial spasm by compressing the facial nerve. This accounts for about 0.8% of cases.

In the early stages of facial spasm, it often presents as intermittent twitching of the orbicularis oculi muscle, also known as "eyelid twitching."

As the condition progresses, it gradually spreads to other facial muscles on one side (e.g., orbicularis oris and facial expression muscles) and may even involve the ipsilateral sternocleidomastoid muscle, with the twitching of the muscles around the mouth corner being the most prominent.

Severe cases may cause facial pain, difficulty in opening the eyes, drooping of the mouth corner, and pulsatile tinnitus. In a few patients in the late stage of the disease, mild paralysis of the muscles on the affected side may occur.

The severity and duration of the twitching vary, lasting from a few seconds to over ten minutes, with intermittent periods. In the early stages, the twitching is milder, and the intermittent periods are longer. As the symptoms worsen, the intermittent periods gradually shorten. Fatigue, emotional excitement or tension, and voluntary facial movements (such as forcefully closing the eyes or puffing the cheeks) can exacerbate the twitching, which stops during sleep.

Currently, there is no unified understanding of the etiology and pathogenesis of facial spasm. Most literature primarily explains the onset of facial spasm from the perspective of four pathological factors—wind, phlegm, stasis, and deficiency—and different aspects such as internal wind of the liver and the liver-stomach meridians. Since there is insufficient in-depth research on the etiology and pathogenesis of facial spasm from the perspective of traditional Chinese medicine theory, the treatment pathways are inconsistent, and the methods are diverse.

To prevent the occurrence of facial spasm, attention should be paid to the following in daily life: keeping warm and protecting the face from cold, maintaining a light diet, exercising regularly, refraining from smoking and drinking, avoiding excessive physical exertion, and maintaining a cheerful disposition without excessive tension.