Шийна дистонія

Cervical dystonia symptoms may begin at any age but usually begin between ages 20 and 60, with a peak between ages 30 and 50 (1).

Symptoms usually begin gradually; rarely, they begin acutely and progress rapidly. Sometimes symptoms begin with a tremor that rotates the neck (in a no-no gesture).

The cardinal symptom of cervical dystonia is

• Painful tonic contractions or intermittent spasms of the sternocleidomastoid, trapezius, and other neck muscles, usually unilaterally, that result in an abnormal head position

Unilateral sternocleidomastoid muscle contraction causes the head to rotate to the opposite side. Rotation may involve any plane but almost always has a horizontal component. Besides rotational tilting (torticollis), the head can tilt laterally (laterocollis), forward (anterocollis), or backward (retrocollis, common when dopamine-blocking medications are the cause). Similarly, in the caput form, the head may tilt laterally (laterocaput), forward (anterocaput), or backward (retrocaput).

Patients may discover sensory or tactile tricks that lessen the dystonic posturing or tremor (geste antagoniste). Touching the face on the side contralateral to the deviation is an example. Noting whether a sensory trick is effective can help clinicians differentiate pathophysiologic dystonia from psychogenic dystonia. Such tricks typically do not lessen psychogenic tremor.

The presence of overflow or mirroring also indicates that a pathophysiologic etiology (eg, genetic, idiopathic, brain injury) is likely. Overflow refers to involuntary dystonic movement in another part of the body, distant to the primary voluntary movement. In mirroring, when patients voluntarily move the affected side of their body, they involuntarily mimic that movement with the opposite side of the body.

During sleep, muscle spasms disappear.

Spasmodic torticollis ranges from mild to severe. Usually, it progresses slowly for 1 to 5 years, then plateaus. About 10 to 15% of patients recover or significantly improve spontaneously within 5 years of onset (usually in milder cases with onset at a younger age). However, in many of those who improve, symptoms recur (2).

• Clinical evaluation

The diagnosis of cervical dystonia is based on characteristic symptoms and signs and exclusion of alternative diagnoses, including the following:

• Tardive dystonia can cause torticollis but can usually be distinguished by a history of chronic antipsychotic use and involuntary movements in muscles outside of the neck.

• Basal ganglia disorders and occasionally central nervous system (CNS) infections can cause movement disorders but usually also involve other muscles; CNS infections are usually acute and cause other symptoms.

• Neck infections or tumors are usually differentiated by features of the primary process.

• Antipsychotics and other medications can cause acute torticollis, but the symptoms usually develop in hours and resolve within days after the medication is stopped.

• Congenital muscular torticollis (fibromatosis colli) is caused by a benign tumor in the sternocleidomastoid muscle. The tumor causes foreshortening of the muscle and tilting of the neck, mimicking cervical dystonia. Head tilting usually appears during infancy or childhood but can occur during adulthood (1).

The collis form of dystonia (involving muscles that control the cervical spine) can usually be distinguished from the caput form (involving muscles that move the skull or head joints) based on observation of the patient. Imaging (CT bone window), in addition to clinical evaluation, is useful only for assessing rotation of the head.  Lateral shift always occurs when laterocollis is present on one side and laterocaput on the other (2).

• Physical measures

• Sometimes botulinum toxin or oral medications

Spasms can sometimes be temporarily inhibited by physical therapy and massage, including sensory biofeedback techniques (eg, slight tactile pressure to the jaw on the same or other side as head rotation) and any light touch.