Diagnosis of Parkinson's disease: Acute challenge

The expression 'Parkinson's disease' (PD) has been used since James Parkinson first wrote a monography dedicated to a movement disorder he called 'shaking palsy.' Since then, PD has been identified as a specific clinical entity. Today, it is commonly accepted that PD is but one of many parkinsonian syndromes that present with overlapping clinical features. About a score of different parkinsonian syndromes have been identified, some of which are primary (eg degenerative, in most instances) while others are secondary. Therefore, although parkinsonian patients are easy to recognize even by the nonclinical eye, it is more difficult to state whether a parkinsonian patient is affected by PD or by another parkinsonian syndrome. Diagnostic issues are intimately related to treatment and prognosis, because parkinsonian syndromes respond differently to medical and surgical treatments and have different natural histories.