Characterization of Mild Cognitive Impairment in Parkinson's Disease

Parkinson's Disease (PD) is characterized as an "α-synucleinopathy," denoting the accumulation of highly phosphorylated and abnormally aggregated α-synuclein. This condition significantly impacts individuals by presenting a spectrum of motor and non-motor symptoms. The neuronal loss in the substantia nigra, located in the midbrain, underlies PD, leading to dopaminergic deficiency and the disruption of the nigra-striatal pathway. This, in turn, may contribute to brain atrophy, white matter alterations, and other related changes. Beyond the well-known motor symptoms like bradykinesia, rigidity, rest tremor, and freezing of gait, PD manifests a range of non-motor symptoms. Among these, Mild Cognitive Impairment (MCI) stands out, reflecting deficits in cognition, behavior, and mood. The degeneration spans several brain areas, including the pre-frontal cortex, limbic region, and midbrain. Consequently, individuals with MCI experience challenges in planning, judgment, memory, emotions, and the reward system. Mild Cognitive Impairment serves as an early indicator of cognitive changes from a healthy state, often affecting one of the five cognitive domains: attention, executive function, language, memory, and visuospatial ability. This thesis reviews existing literature on Mild Cognitive Impairment in Parkinson’s Disease, with a specific focus on associated biomarkers and clinical characterization.