The relationship of peripheral trauma and pain to dystonia.

Four patients are described who sustained comparatively minor peripheral injury, the affected area soon becoming the site of segmental dystonia. The movement disorder developed as the symptoms from the injury subsided, and except for the recent trauma, no cause for the dystonia was apparent; litigation was not an issue for any patient. It is suggested that on rare occasions peripheral trauma results in the development of dystonia. Since injury never involved the head, the role of the spinal dopaminergic system and the relevance of pain from the injury are discussed in considering possible underlying mechanisms.