[Atypical Parkinson syndromes].

At the moment atypical Parkinson syndromes have unfavorable prognoses and show little response to dopaminergic medication. Early differential diagnosis of these disorders from idiopathic Parkinson syndrome is of pivotal clinical relevance. In case of future causal, neuroprotective therapeutic strategies, early diagnosis will allow a timely start of therapy. In the early stage of disease, it might be difficult clinically to distinguish multiple system atrophy, progressive supranuclear palsy, and corticobasal ganglionic degeneration from idiopathic Parkinson syndrome. Additional electrophysiological, imaging, and nuclear medical investigations may support the clinical diagnosis. During disease progression clinical signs indicative of an atypical Parkinson syndrome should always warrant reevaluation of the diagnosis.