On first appearance, dystonia is a movement disorder. It is characterized by abnormal postures and movements. Sensation seems normal. There are clues, however, that sensory function may not be completely normal and that sensory features are important. Since the sensory system is an important influence on the motor system, abnormalities of the sensory system could be relevant in causing motor dysfunction.
Sensory tricks can relieve a dystonic spasm.
Such tricks are seen in all forms of dystonia. On the other hand, sensory stimulation might trigger dystonia. Examples include a tart taste producing tongue dystonia or a loud noise producing spasmodic torticollis. Sensory symptoms may well precede the appearance of dystonia. Common examples would be a gritty sensation in the eye preceding blepharospasm and irritation of the throat preceding spasmodic dysphonia.