Torticollis, the most frequent form of restricted dystonia, is localized to the neck and adjacent muscles. It usually begins as a subtle tilting or turning of the head that tends to worsen slowly, first evident in early to middle adult life, somewhat more commonly in women (peak incidence in the fifth decade) (extreme form shown in Fig. 4-8A). With the exception of the finding of DYT1 gene abnormality in a few patients, it is idiopathic. The quality of the neck and head movements varies greatly. Intermittent turning or tilting of the head may be deliberate and smooth, or jerky, but more typically there is a sustained deviation or tilting of the head to one side. Sometimes brief bursts of twitching or an irregular, high-frequency tremor accompanies deviation of the head, beating in the direction of the dystonic movement. At times the tremor is more dominant than is the dystonia, causing difficulty in diagnosis. The spasms are often worse when the patient stands or walks and are characteristically reduced or abolished by a contactual stimulus, such as placing a hand on the chin or neck; exerting mild but steady counterpressure on the side of the deviation or less often on the opposite side; or bringing the occiput in contact with the back of a high chair. These maneuvers, termed gestes, or “sensory tricks” become less effective as the disease progresses. In many cases, the spasms are reduced when the patient lies down. In chronic cases, as the dystonic position typically becomes increasingly fixed in position, the affected muscles undergo hypertrophy. At that late stage, pain in the contracting muscles is common.
In a few of our patients, the condition disappeared without therapy, an occurrence observed in 10 to 20 percent in the series of Dauer et al. In their experience, remissions usually occurred during the first few years after onset in patients whose disease began relatively early in life; however, nearly all these patients relapsed within 5 years.
The most prominently affected muscles are the sternocleidomastoid, levator scapulae, and trapezius. EMG studies also show sustained or intermittent activity in the posterior cervical muscles on both sides of the neck. The levator spasm lifts the affected shoulder slightly, and tautness in this muscle is sometimes the earliest feature. As a general observation, we have been impressed with information gained from palpating the muscles of the neck and shoulder in order to establish which muscles are the predominant causes of the spasm and to direct treatment to them as noted further on. In most patients the spasms remain confined to the neck muscles and persist in unmodified form, but in some the spasms spread, involving muscles of the shoulder girdle and back or the face and limbs. The distinction between these patterns is not fundamental. About 15 percent of patients with torticollis also have oral, mandibular, or hand dystonia, 10 percent have blepharospasm, and a similarly small number have a family history of dystonia or tremor (Chan et al). As already noted, no neuropathologic changes have been found in case studies, for example, those reported by Tarlov and by Zweig and colleagues.
Spasmodic torticollis is resistant to treatment with L-dopa and other antiparkinsonian agents, although occasionally they give slight relief. The drugs are, however, effective in those few instances in which dystonia is a prelude to Parkinson disease. Trihexyphenidyl or benztropine, used in the past in high doses for dystonia, may allow some amelioration but they are difficult to tolerate.