Most patients with primary facial muscle spasm develop after middle age, with more women. In the early stage of the disease, it is mostly paroxysmal involuntary twitching of the orbicularis oculi muscle on one side, which gradually and slowly expands to the other facial muscles on one side of the face, and the twitching of the corners of the mouth is the most noticeable. The degree of twitching varies, and it is paroxysmal, rapid and irregular twitching. The initial twitch is light and lasts only a few seconds, and then it gradually grows longer for several minutes or longer, while the interval is gradually shortened and the twitches are gradually increased frequently. In severe cases, it is tonic, causing the ipsilateral eye to be unable to open, the corner of the mouth to be skewed to the ipsilateral side and unable to speak, often aggravated by fatigue, nervousness and voluntary movement, but it cannot imitate or control its onset by itself. A convulsion can last from a few seconds to more than 10 minutes, with intervals of variable length. The patient feels distracted and unable to work or study, which seriously affects the patient’s physical and mental health. Most of the convulsions stop after sleep. Bilateral lateral muscle spasms are rarely seen. If there is, it is often started on both sides successively, and most of the convulsions stop on one side, then the other side has another attack, and the convulsions are light on one side and light on the other side, and the simultaneous onset and convulsions on both sides have not been reported. A few patients have mild facial pain during the convulsions, and individual cases may be accompanied by ipsilateral headache and tinnitus. The neurological examination was not positive except for paroxysmal twitching of facial muscles. A few patients may have mild paralysis of the affected lateral muscles in the late stage of the disease. Grade 0: no spasticity; Grade 1: increased transients or mild tremors of facial muscles due to external stimuli; Grade 2: spontaneous mild tremors of eyelids and facial muscles without dysfunction; Grade 3: pronounced spasticity with mild dysfunction; Grade 4: severe spasticity and dysfunction, e.g., the patient is unable to read and has difficulty walking alone because he cannot keep his eyes open.