20th July 2023

Pathophysiology

PD is a neurodegenerative disorder affecting the central nervous system. The onset is usually gradual, and as the disease progresses, both motor and non-motor symptoms occur. The area of the brain affected is the substantia nigra (midbrain,) where cell necrosis causes a reduction in dopamine levels. As dopamine plays a key role in regulating movement, this manifests as akinesia. It is thought that the degree of cell loss correlates clinically with the extent of akinesia. This leads to the accumulation of Lewy bodies (eosinophilic inclusion bodies) which contain ubiquitin and alpha-synuclein in the neurons.

PD has a variety of presentations which can be divided into motor (such as tremors and rigidity), and non-motor symptoms (cognitive, sleep disorder, and mood).