Cholinergic Basal Forebrain Integrity and Cognition in Parkinson's Disease: A Reappraisal of Magnetic Resonance Imaging Evidence

• Published in: Movement disorders 2024-12, Vol.39 (12), p.2155-2172
• Main Authors: Slater, Nicola M., Melzer, Tracy R., Myall, Daniel J., Anderson, Tim J., Dalrymple‐Alford, John C.
• Format: Article
• Language: English
• Subjects: Basal forebrain; Basal Forebrain - diagnostic imaging; Basal Forebrain - pathology; cholinergic basal forebrain; cholinergic system; Cholinergic transmission; cognition; Cognition - physiology; Cognitive ability; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - etiology; Cognitive Dysfunction - physiopathology; Dementia disorders; Forebrain; Humans; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Methane; Movement disorders; Neurodegenerative diseases; Nucleus basalis; Parkinson Disease - complications; Parkinson Disease - diagnostic imaging; Parkinson Disease - pathology; Parkinson's disease; Parkinson's disease dementia; Positron emission tomography; Review
• ISSN: 0885-3185; 1531-8257; 1531-8257
• DOI: 10.1002/mds.30023

Cognitive impairment is a well‐recognized and debilitating symptom of Parkinson's disease (PD). Degradation in the cortical cholinergic system is thought to be a key contributor. Both postmortem and in vivo cholinergic positron emission tomography (PET) studies have provided valuable evidence of cholinergic system changes in PD, which are pronounced in PD dementia (PDD). A growing body of literature has employed magnetic resonance imaging (MRI), a noninvasive, more cost‐effective alternative to PET, to examine cholinergic system structural changes in PD. This review provides a comprehensive discussion of the methodologies and findings of studies that have focused on the relationship between cholinergic basal forebrain (cBF) integrity, based on T1‐ and diffusion‐weighted MRI, and cognitive function in PD. Nucleus basalis of Meynert (Ch4) volume has been consistently reduced in cognitively impaired PD samples and has shown potential utility as a prognostic indicator for future cognitive decline. However, the extent of structural changes in Ch4, especially in early stages of cognitive decline in PD, remains unclear. In addition, evidence for structural change in anterior cBF regions in PD has not been well established. This review underscores the importance of continued cross‐sectional and longitudinal research to elucidate the role of cholinergic dysfunction in the cognitive manifestations of PD. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.