Characteristics of dystonic movements in primary and symptomatic dystonias

OBJECTIVE: To compare clinical characteristics of the involuntary movements in primary and symptomatic dystonias. PATIENTS AND METHODS: 132 consecutive patients with the diagnosis of primary dystonia and 51 consecutive patients with secondary dystonia caused by well defined structural lesion(s) of the central nervous system, with particular emphasis on the characteristics of involuntary movements. RESULTS: Eight variables with the highest risk contribution to either symptomatic or primary dystonias were identified: dystonic movement in secondary dystonia was much more frequently presented at rest, whereas the presence of dystonic tremor, chronic inflammatory process, or peripheral trauma located in the region that is later affected by dystonia, as well as the use of sensory tricks and development of spontaneous remissions, classified the affected patients more often in the category of those with primary dystonia. CONCLUSION: The study identified several clinical features that may be helpful in differentiating primary from secondary dystonia.