ABSTRACT
INTRODUCTION This chapter reviews the pathophysiology of primary dystonia, and mainly adultonset, focal hand dystonia (writer’s cramp), as it is often the condition most amenable to physiological investigation. The anatomical localization for primary dystonia is poorly understood, but when symptomatic, often involves the basal ganglia (1). Anatomical imaging and routine pathological investigations in primary dystonia are generally normal. Another chapter will review functional neuroimaging fi ndings of dystonia and pathology. This chapter concentrates on neurophysiological investigation with electromyography (EMG), electroencephalography (EEG), nerve and refl ex testing, and transcranial magnetic stimulation (TMS).
