A multitude of conditions may lead to the development of<unk>  including: muscular fibrosis, congenital spine abnormalities, or toxic or traumatic brain injury. A rough categorization discerns between congenital<unk>  and acquired<unk> . Other categories include: * Osseous * Traumatic * CNS/PNS * Ocular * Non-muscular soft tissue * Spasmodic * Drug induced * Oral ties (lip and tongue ties) Congenital muscular<unk>  The congenital muscular<unk>  is the most common<unk>  which is present at birth. The cause of congenital muscular<unk>  is unclear. Birth trauma or intrauterine malposition is considered to be the cause of damage to the sternocleidomastoid muscle in the neck. Other alterations to the muscle tissue arise from repetitive microtrauma within the womb or a sudden change in the calcium concentration in the body which causes a prolonged period of muscle contraction. Any of these mechanisms can result in a shortening or excessive contraction of the sternocleidomastoid muscle, which curtails its range of motion in both rotation and lateral bending. The head typically is tilted in lateral bending toward the affected muscle and rotated toward the opposite side. In other words, the head itself is tilted in the direction towards the shortened muscle with the chin tilted in the opposite direction. Congenital<unk>  is presented at 1–4 weeks of age, and a hard mass usually develops. It is normally diagnosed using ultrasonography and a colour histogram or clinically through evaluating the infant's passive cervical range of motion. Congenital<unk>  constitutes the majority of cases seen in clinical practice. The reported incidence of congenital<unk>  is 0.3-2.0%. Sometimes a mass, such as a sternocleidomastoid tumor, is noted in the affected muscle.<unk>  does not resolve on its own and may result in plagiocephaly. Acquired<unk>  Noncongenital muscular<unk>  may result from scarring or disease of cervical vertebrae, adenitis, tonsillitis, rheumatism, enlarged cervical glands, retropharyngeal abscess, or cerebellar tumors. It may be spasmodic (clonic) or permanent (tonic). The latter type may be due to Pott's Disease (tuberculosis of the spine). * A self-limiting spontaneously occurring form of<unk>  with one or more painful neck muscles is by far the most common ('stiff neck') and will pass spontaneously in 1–4 weeks. Usually the sternocleidomastoid muscle or the trapezius muscle is involved. Sometimes draughts, colds, or unusual postures are implicated; however, in many cases, no clear cause is found. These episodes are commonly seen by physicians. Most commonly this self-limiting form relates to an untreated dental occlusal dysfunction, which is brought on by clenching and grinding the teeth during sleep. Once the occlusion is treated it will completely resolve. Treatment is accomplished with an occlusal appliance, and equilibration of the dentition. * Tumors of the skull base (posterior fossa tumors) can compress the nerve supply to the neck and cause<unk> , and these problems must be treated surgically. * Infections in the posterior pharynx can irritate the nerves supplying the neck muscles and cause<unk> , and these infections may be treated with antibiotics if they are not too severe, but could require surgical debridement in intractable cases. * Ear infections and surgical removal of the adenoids can cause an entity known as Grisel's syndrome, a subluxation of the upper cervical joints, mostly the atlantoaxial joint, due to inflammatory laxity of the ligaments caused by an infection. * The use of certain drugs, such as antipsychotics, can cause<unk> . * Antiemetics - Neuroleptic Class - Phenothiazines * There are many other rare causes of<unk> . A very rare cause of acquired<unk>  is fibrodysplasia ossificans progressiva (FOP), the hallmark of which is malformed great toes. Spasmodic<unk> <unk>  with recurrent, but transient contraction of the muscles of the neck and especially of the sternocleidomastoid, is called spasmodic<unk> . Synonyms are "intermittent<unk> ", "cervical dystonia" or "idiopathic cervical dystonia", depending on cause. Trochlear<unk> <unk>  may be unrelated to the sternocleidomastoid muscle, instead caused by damage to the trochlear nerve (fourth cranial nerve), which supplies the superior oblique muscle of the eye. The superior oblique muscle is involved in depression, abduction, and intorsion of the eye. When the trochlear nerve is damaged, the eye is extorted because the superior oblique is not functioning. The affected person will have vision problems unless they turn their head away from the side that is affected, causing intorsion of the eye and balancing out the extorsion of the eye. This can be diagnosed by the Bielchowsky test, also called the head-tilt test, where the head is turned to the affected side. A positive test occurs when the affected eye elevates, seeming to float up.
Torticollis
Spasmodic torticollis
Equinovalgus
Abulia
Pseudostrabismus
Dysbarism
Strabismus
Diplegia