Neuropathology and immunocytochemical study in Parkinson's disease : a report of two cases.

Despite a high clinical prevalence rate of Parkinson's disease in India, autopsy studies have not been reported in the country, till date. Two autopsied cases clinically diagnosed as Parkinson's disease in our Institute were neuropathologically evaluated. Clinically, they presented with the classical features typical of the disease like tremors, rigidity, mask-like facies and bradykinesia. A distinct loss of melanin-containing neurons of the substantia-nigra in the midbrain and in the locus ceruleus was observed. Characteristic single and multiple intraneuronal Lewy bodies were seen in the substantia nigra, locus ceruleus and occasionally in the basal nucleus of Meynert, posterior thalamic nucleus and neurons of occulomotor nucleus. Immunohistochemically, these classical Lewy bodies were ubiquitin in positive, showing two morphological forms: one, as a homogenous dense body and the other, as a peripheral dense staining with a central lucent zone. These bodies failed to react with the neurofilament antibodies. The neuronal loss in the midbrain was associated with gliosis, confirmed by PTAH and GFAP immunostaining. There were no features of dementia, either clinically or neuropathologically in both cases.