Diagnostic criteria for multiple system atrophy and progressive supranuclear palsy.

The atypical parkinsonian disorders (APD) embrace a heterogeneous group of movement disorders all characterized by prominent parkinsonism, accompanied by specific additional features such as cerebellar ataxia, early autonomic dysfunction, early dementia, pyramidal tract signs, myoclonus, supranuclear gaze palsy, apraxia which are atypical for idiopathic Parkinson's disease (PD). Beside these features, rapid disease progression and poor or absent response to L-Dopa therapy both raise the suspicion of an APD. Currently, multiple system atrophy (MSA), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and dementia with Lewy bodies (DLB) are referred to as APD. Clinical diagnosis can be difficult in early stages and although the predictive value of the widely established, diagnostic criteria is high at first neurological evaluation sensitivity tends to be poor and may be less than 30%. In this review, we will discuss diagnostic issues in MSA and PSP.