[Parkinson's disease and parkinsonian syndromes]

The parkinsonian syndrome rests on the clinical tripod: akinesia, rigidity, tremor. Akinesia is the key symptom, broadly defined as a difficulty in initiating and performing movements in proportion to their complexity (sophisticated, simultaneous movements) and their duration (repetitive movements). The most frequent cause of the syndrome is Parkinson's disease. Although this diagnosis needs to be confirmed in pathological terms by the loss of neurons and the presence of Lewy's bodies in the substantia nigra, some clinical data enable it to be envisaged with a minimum of errors; these are pure parkinsonian triad, good response to dopatherapy and asymmetrical symptoms. The other causes of parkinsonian syndrome are usually related to the administration of neuroleptic drugs and to degenerative diseases with lesions that are more diffuse than those of Parkinson's disease. In Steele-Richardson-Olzewski disease a parkinsonian syndrome is associated with supranuclear ophthalmoplegia. Multiple systematized atrophy presents under three different clinical aspects: a parkinsonian syndrome without tremor and resistant to L-dopa, suggesting atrophy of the strionigral tract; a parkinsonian syndrome associated with a cerebellar syndrome, suggesting olivo-cerebellar-pontine atrophy, and Shy-Drager disease which includes primary dysautonomy and other neurological syndromes.