Dystonia Associated with Idiopathic Slow Orthostatic Tremor

We aimed to characterize the clinical and electrophysiological features of patients with slow orthostatic tremor. The clinical and neurophysiological data of patients referred for lower limb tremor on standing were reviewed. Patients with symptomatic or primary orthostatic tremor were excluded. Eight patients were identified with idiopathic slow 4-8 Hz orthostatic tremor, which was associated with tremor and dystonia in cervical and upper limb musculature. Coherence analysis in two patients showed findings different to those seen in primary orthostatic tremor. Slow orthostatic tremor may be associated with dystonia and dystonic tremor.