1.Concept of spastic squint Spastic squint is a paroxysmal involuntary contraction of the neck muscles caused by abnormal impulses of the central nervous system, causing the head and neck to twist to one side or tilt spastically. 2. Etiology of spastic squint Most of them are caused by degeneration of nucleus pulposus-basal node, which is located in the deep part of the brain. These patients can have a history of encephalitis, birth asphyxia, jaundice, etc. These will show some abnormalities on CT or MRI. There are also some patients who do not have any changes on imaging. In a few patients, it can be caused by hysterical episodes or local irritation (cervical spine injury or inflammation) in the periphery. 3. Clinical manifestations of spastic squint The various abnormal postures of spastic squint are caused by the abnormal contraction of the muscles in the corresponding parts of the neck. The contraction of sternocleidomastoid muscle, trapezius muscle and cephalicus muscle is the most likely to show symptoms. When one sternocleidomastoid muscle contracts, the head rotates to the opposite side; when both sternocleidomastoid muscles contract simultaneously, the head flexes forward; when both cephalicus and trapezius muscles contract simultaneously, the head overextends posteriorly. In severe spasticity, hypertrophy of the affected muscles can occur. (1) Rotation type: The head is spasmodically rotated to one side along the longitudinal axis of the body. (2) Posterior tilt type: The head is tilted backward towards the back, facing the sky. (3) Forward flexion type: The head is flexed forward with the jaw against the chest. (4) Lateral flexion type: The head deviates from the longitudinal axis to the left or right, with the ear close to the shoulder, often accompanied by ipsilateral shrugging of the shoulder. The above is part of the knowledge of spastic squint, which, in general, belongs to the diagnosis and treatment of neurology. There are reports of high success rate of treating spastic squint by selective cervical muscle resection and paraneoplastic neurectomy. Degenerative changes in the cervical spine can be an activating factor in the development of spastic strabismus. Curing cervical spondylolisthesis by removing abnormal irritation in the neck can sometimes achieve the goal of curing spastic squint. However, regardless of the method, the results are not ideal.