Generally speaking, early diagnosis of spastic squint is based on the symptoms and signs of the disease. Spastic squint is mainly due to the involuntary contraction of the sternocleidomastoid and trapezius muscles, which causes the head to twist to one side or tilt in a clonic manner. The early manifestations are usually a periodic turning of the head to one side, or a forward or backward tilt. The affected muscles are often painful and may become enlarged. In addition, the symptoms may worsen if the patient is emotionally agitated, and they are relieved when the hand is resting on the jaw, face or occiput, and usually disappear during sleep.