Spastic squint is a condition in which the neck muscles show paroxysmal involuntary contractions, causing the head and neck to be in various tilted or rotated positions. Its prevalence is gender- and age-related, with the prevalence in women usually 1.5-1.9 times higher than that in men. The peak age of onset is 50-60 years old. Clinical manifestations] The disease is aggravated during activity or work stress, and the symptoms are reduced or disappear during sleep. Symptoms often appear suddenly as a “pulling or dragging of the neck” or as an involuntary rotation or sharp turn of the head. Atypical symptoms may lead to misdiagnosis as “arthritis, cervical radiculopathy, psychiatric disorders, Parkinson’s or TMJ syndrome. Diagnosis】 The disease is diagnosed by symptoms: the head and neck are not in alignment, the neck muscles are tense, forced to deflect, difficult to control, some patients can be corrected for a moment, but can not last and return to the original state, and in severe cases, the deflection can not be corrected. The symptoms are aggravated by emotional tension and exertion. The symptoms disappear after sleep, which affects the normal work, study and life of patients. Spastic squint] is divided into four types according to the symptoms: 1. Rotation type: The head rotates spastically or clonically to one side around the longitudinal axis of the body. According to whether the head is tilted with the longitudinal axis, it can be divided into three subtypes: horizontal rotation, backward rotation and forward flexion rotation. The rotation type is the most common type of the disease, in which the posterior-supination type is slightly more common, the horizontal type is second, and the forward-flexion type is less common. In addition, according to the muscle contraction, it can be divided into spasticity and clonicity. In the former case, the patient’s head rotates to one side in a persistent and tense manner; in the latter case, it rotates back and forth frequently. 2.Backward tilt type: The patient’s head is spasmodically or paroxysmally tilted backward, with the face facing the sky. 3.Foreflexion type: The patient’s head is spasmodically or paroxysmally foreflexed toward the chest. 4.Lateral contracture type: The patient’s head deviates from the longitudinal axis and turns to the left or right. In severe cases, the ear and temporal area may be forced or close to the shoulder, and often accompanied by the phenomenon of ipsilateral shoulder elevation. The examination can reveal that the neck muscles have spasm, especially the synergic muscles (a group of muscles that together cause ‘slant neck’) have synchronous spasm. By repeating the movement of slant neck, we can initially determine the range of muscles involved. The electromyography shows abnormally high wave amplitude in the neck of the major and minor spastic muscles CT can show the involved muscles and the degree of hypertrophy [Treatment] 1. Botulinum toxin injections into the affected muscles are effective, but not curative. With drug tolerance, the efficacy is shortened after injection. 2.Surgical treatment (1) Anterior cervical nerve root and paraneoplastic nerve root amputation: also known as Foester-Dandy surgery. The anterior nerve roots of the upper cervical 1-3 nerves are cut under the microscope, and the collateral nerve roots are cut in the vertebral artery plane. (2) Stereotactic surgery: For the rotated or tilted type, the ventral anterior nucleus of the thalamus (VA), its pallidum and nigrostriatal-thalamic afferent fibers are destroyed, and the efficacy can reach 36%-73%. However, surgery can lead to complications such as hemiparesis, aphasia, and ataxia, and is now less commonly used. (3) Selective cervical muscle and neurectomy: for rotating type of oblique neck, only the ipsilateral cephalic grip muscle and the contralateral paraspinal nerve can be removed; for posterior-supination type of oblique neck, some of the left and right rhomboid muscles, cephalic grip muscle, head and cervical semispinal muscles can be surgically removed; for forward-flexing type of oblique neck, the bilateral paraspinal nerve can be cut; for lateral-bending type of oblique neck, the cephalic grip muscle and scapular raphe muscle on the side of head bending can be done, and individual patients with spasm of ipsilateral sternocleidomastoid muscle can also have additional Paraneoplastic neurectomy. (4) Selective peripheral neurectomy: This method mainly cuts the posterior branch of cervical nerve root, and the scope of cutting is selected according to the number of spastic muscle groups. This method is effective for rotating type of oblique neck. (5) Microvascular decompression of the parasympathetic nerve roots: Under the operating microscope, we can observe whether there are blood vessels around the parasympathetic nerve roots that are compressing the nerve, usually the vertebral artery, the posterior inferior cerebellar artery or the posterior spinal cord artery.