Head CT > Degenerative > Parkinson's Disease > Pathophysiology

Parkinson's Disease - Pathophysiology

One possible etiology of Parkinson's disease may be a defect in complex 1 of the mitochondrial electron transport chain with resultant dysfunction and production of free radicals and oxidative damage. Histopathologically, there is a selective loss of neuromelanin containing dopaminergic neurons within the pars compacta of the substantia nigra. Additionally, the retrorubral area and ventral tegmental area of the midbrain may also show significant neuronal loss.

Destruction of these neurons leads to disruption of the normal projections to the neostriatum, limbic structures, and selected cortical forebrain areas. When 80-85% of these nigral neurons degenerate and at least 80% of the striatal dopamine content is lost, symptoms of this movement disorder may be manifested. Currently the most commonly employed treatment consists of dopaminergic and anticholinergic medications.