Echogenic substantia nigra in patients with orthostatic tremor

Summary. Objectives: Previous studies suggest that the nigrostriatal dopaminergic transmission is impaired in patients with primary orthostatic tremor. Methods: We used transcranial sonography (TCS) to examine the morphology of the substantia nigra (SN) in four patients with primary orthostatic tremor (OT). Results: TCS revealed an SN echogenicity in all patients, in three patients unilaterally, in one patient bilaterally. Conclusions: Our data suggest nigrostriatal dopaminergic deficits in OT patients. The exact impact of these dopaminergic deficits on OT generation is unclear.