Spastic squint is the most common type of focal dystonia and is most common in adults, with an average age of onset of about 40 years. The clinical manifestations are uncontrollable spasms or clonus of the cervical muscles caused by abnormal impulses of the central nervous system, resulting in involuntary spastic tilt and twist of the head and neck, resulting in hyperactivity and abnormal posture, which may be accompanied by spasmodic pain of the corresponding muscles, usually involving the sternocleidomastoid, trapezius, cephalicus and scapularis muscles. Etiology: The exact etiology is unclear. There is increasing evidence that genetic factors (more than 20 genes such as DYT6 and DYT7 have been found to be associated with the development of dystonia) are closely related to the disease; psychiatric factors are also a major cause of the onset of symptoms. Clinical typology: 1. Rotation type: The head is involuntarily rotated spasmodically or clonically to one side around the longitudinal axis of the body. According to the tilt of the head and the longitudinal axis, there are three subtypes: horizontal rotation, backward rotation and forward flexion rotation. 2. Forward flexion type: The head involuntarily flexes spasmodically or paroxysmally toward the chest. 3.Backward tilting type: the head involuntarily spasms or clonic flexion toward the chest, with the face facing the sky. 4.Lateral tilt type: the head deviates from the longitudinal axis and involuntarily tilts spasmodically or paroxysmally to the left or right. In fact, there are various symptoms of spastic squint, most of which are manifested as a combination of multiple types of abnormal postures. Symptoms are usually aggravated by exertion, walking, mood swings, fatigue or sensory stimulation, and are reduced when quiet and disappear after sleep. Treatment: 1. Medication and Botulinum toxin local injection treatment Medication may be effective in the early stage, but the effect is limited and short-lived, such as diazepam, baclofen and, Antan and haloperidol, etc., may play a role in reducing the degree of seizures in the early stage, and the effect is not obvious in the middle and late stages. Botulinum toxin local injection treatment is a simple, safe and effective method to relieve symptoms and improve the quality of life in the short term, one injection can last 3-6 months, repeated injections are easy to produce antibodies and make the treatment effect diminish. 2.Surgical treatment (1) Traditional surgical treatment ① Selective neurectomy: the operation is more mature, targeted, effective and less complications. The effect is satisfactory for rotational type or combined with mild forward flexion/retroversion type. The surgery is more invasive and sometimes the spasticity is not completely relieved or recurred. ②Fostor-Dandy procedure: i.e., intradural severing of bilateral anterior C1-4 roots and bilateral parasympathetic nerve roots, but due to the large physiological destruction, the more severing the side effects become more obvious, such as neck weakness and swallowing difficulties. Postoperative complications are many and have been used less frequently. (iii) Microvascular decompression: i.e., microvascular decompression of the bilateral collateral nerves and nerve roots above C2. It has been questioned due to the usually large number of muscles involved in spastic squint and the fact that its rationale is completely different from the current understanding of the etiology of dystonia. (4) Stereotactic brain motor nucleus disruption: targeting the pallidum, ventral lateral thalamic nucleus, Froel-H, and central thalamic nucleus, etc. The application is decreasing due to low efficiency and the possibility of serious complications. (2) Deep brain stimulation (DBS): The target point is thalamic nucleus (STN) or medial nucleus of the pallidum (Gpi). Compared with stereotactic disruption, DBS has the characteristics of modifiability, less complications and higher safety, and gradually becomes the mainstream method for the treatment of spastic squint.