Currently, no reliable predictors of cognitive impairment in Parkinson’s disease exist. The authors hypothesized that microstructural changes in specific cholinergic and limbic pathways underlie cognitive impairment in Parkinson’s disease. They performed cross-sectional comparisons between patients with Parkinson’s disease with and without cognitive impairment. They also performed longitudinal 36-month follow-ups of cognitively intact Parkinson’s disease patients. Parkinson’s patients with cognitive impairment showed lower grey matter volume and increased mean diffusivity in the nucleus basalis of Meynert, compared to Parkinson’s patients without cognitive impairment. Structural and microstructural alterations in entorhinal cortex, amygdala, hippocampus, insula, and thalamus were not predictive for cognitive impairment in Parkinson’s disease. The study concluded that degeneration of the nucleus basalis of Meynert precedes and predicts the onset of cognitive impairment, and might show use as a reliable biomarker in patients at risk of cognitive decline.
Schulz J, Pagano G, Fernández Bonfante JA, Wilson H, Politis M: Nucleus basalis of Meynert degeneration precedes and predicts cognitive impairment in Parkinson’s disease. Brain 141(5):1501-1516 (2018).