Differential diagnosis of parkinsonism.

The diagnosis of idiopathic Parkinson's disease (PD) is essentially clinical and is reached by exclusion. An akinetic rigid syndrome frequently means PD, although a number of other neurodegenerative diseases can share bradykinesia, rigidity, postural instability, and sometimes tremor. Parkinsonism can be classified as follows: degenerative, metabolic, vascular, iatrogenic, toxic, infectious, traumatic, and secondary to mass effect. The diagnostic approach are discussed.