Brain Atrophy Is Cognitive Biomarker in Parkinson's
Increased hippocampal atrophy seen in Parkinson's with mild or dementia-level cognitive defects
WEDNESDAY, Dec. 14 (HealthDay News) -- Patients with Parkinson's disease (PD) with mild cognitive impairment (PD-MCI) and dementia-level cognitive deficits (PDD) have increased brain atrophy, compared with patients with PD with normal cognition (PD-NC), according to a study published in the December issue of the Archives of Neurology.
Daniel Weintraub, M.D., from the University of Pennsylvania in Philadelphia, and colleagues assessed the regions and patterns of brain atrophy in patients with PD-NC, PD-MCI, and PDD. A total of 84 patients with PD (61 with PD-NC, 12 with PD-MCI, and 11 with PDD), and 23 healthy controls (HCs) underwent magnetic resonance imaging. Using a region-of-interest approach and voxel-based morphometry analysis, images were quantified. A high-dimensional pattern classification approach was used to delineate brain regions which formed the Spatial Pattern of Abnormalities for Recognition of PDD.
The investigators found that, compared with HCs, there was no significant brain atrophy in PD-NC patients. PD-MCI patients had significant hippocampal atrophy, and PDD patients had significant hippocampal and medial temporal lobe atrophy, compared with PD-NC patients. The pattern of atrophy in PD-MCI patients was significantly different from PD-NC patients and similar to PDD patients (P = 0.04 and 0.81, respectively); and was characterized by atrophy of the hippocampus, prefrontal cortex gray and white matter, occipital lobe gray and white matter, and parietal lobe white matter. A correlation was found between memory-encoding performance and hippocampal volume in PD patients without dementia.
"Hippocampal atrophy is a biomarker of initial cognitive decline in PD, including impaired memory encoding and storage, suggesting heterogeneity in the neural substrate of memory impairment," the authors write.