Abstract

Dystonia is a neurological condition which causes sustained muscular contractions of an involuntary and patterned nature that induce abnormal postures and twisting movements of the affected body region. A complete understanding of the pathogenesis of dystonia remains to be established, however recent studies suggest abnormalities in somatosensory processing play a key role in the initiation of dystonia. We present the case of a young male who developed sustained, patterned, involuntary movements of his upper limbs following cervical myelopathy induced by a whiplash injury. The movements were not altered after eye closure, therefore were dystonic rather than pseudoathetoid in nature. The dystonia was associated with markedly impaired upper limb proprioception secondary to the myelopathy. Both the dystonia and proprioception improved following a C3-C6 cervical laminectomy and lateral mass fusion surgical procedure. Our case is very rare and only one similar case has previously been reported. We propose that this gentleman developed dystonia due to impaired proprioception caused by his cervical myelopathy. This interesting and important case provides further evidence for the proposal that impaired sensory function is involved in the pathophysiology of dystonia. An improved understanding of the mechanisms causing dystonia will hopefully lead to improved treatment for this disabling condition.