Features of probable multiple system atrophy patients identified among 4770 patients with parkinsonism enrolled in the multicentre registry of the German Competence Network on Parkinson's disease.

We identified 221 patients with probable multiple system atrophy (MSA) among 4770 patients enrolled in the multicentre registry of the German Competence Network on Parkinson's disease (PD) according to the established consensus criteria to characterize their clinical presentation. Analyses of more than 100 recorded clinical items revealed several specifics: I) 50% of patients with probable MSA had asymmetry of symptoms at disease onset and tremor at rest was present in 25%; II) a positive response to levodopa was recorded in 51% of patients identified initially with severe autonomic failure and cerebellar ataxia; III) a positive family history was recorded in 11% (n = 23), two of these patients were identified with spinocerebellar ataxia type 3 (SCA3). Thus asymmetry of symptoms, tremor at rest and a positive response to levodopa are not as specific for idiopathic PD as believed previously. Patients with SCA3 may present with the clinical features of MSA.