Progression of dystonia in complex regional pain syndrome.

To the Editor: Oaklander's report 1 of a patient with complex regional pain syndrome (CRPS) in addition to a movement disorder is an excellent example of the value of videotape publications. The patient is described as having progressive right lower extremity dystonia and tremor in the contralateral foot. That the movements began abruptly after vein stripping is stated as evidence that neither psychological factors nor disuse could have caused the movements, hence their organic nature as part of CRPS. Psychogenic movement disorders can be difficult to diagnose and neurologists and other physicians are often reluctant to make the diagnosis despite well-established criteria. 2-4 In contrast to Oaklander's claim, the abrupt onset of a movement disorder is a clue about a psychogenic etiology, as is adult-onset dystonia beginning in the lower extremity. Another clue is the presence of more than one movement disorder. Furthermore, there is controversy about the organic etiology of posttraumatic movement disorders, such as following vein stripping. The videotape provides additional evidence: the patient exhibits a fixed dystonic posture of the right foot (another feature suggestive of psychogenic dystonia) with an atypical low amplitude, high frequency tremor of the involved foot (not typical of dystonic tremor) and an equally atypical " bouncy " whole-leg tremor of the contralateral lower extremity. The historical and physical features of this patient support a psychogenic movement disorder. This report should not be used as evidence that movement disorders are an accepted part of the complex regional pain syndrome. To the Editor: We read with interest Oaklander's description of a " healthy " 35-year-old woman with a progressive and eventually fixed right foot plantarflexion-inversion dystonia. 1 The videotape also demonstrates an irregular, low amplitude tremor in the right foot and a very regular plantarflexion-dorsiflexion tremor of her left foot that was thought to represent spread of her condition to the contralateral leg. We believe the clinical features of the pa-tient's tremor are most consistent with psychogenic tremor as is possibly her entire condition. The syndrome of CRPS associated with development of fixed dystonia has been termed causalgia-dystonia syndrome. 5 Fixed dystonias were recently reviewed by Schrag et al., 6 and up to 37% of the 41 prospectively followed patients in this series met diagnostic criteria for psychogenic dystonia, and 29% fulfilled DSM-IV diagnostic criteria for somatization disorder. 6 In contrast, only two patients were previously diagnosed with somatization disorder in this series, 6 …