Prospective Memory Deficits in Multiple Sclerosis: Voxel-based Morphometry and Double Inversion Recovery Analysis
Megumi Toko1, Juri Kitamura1,2, Hiroki Ueno1
1Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Japan.
Abstract:
Objective Prospective memory (PM) is an important social cognitive function in everyday life. PM is one of the most affected cognitive domains in multiple sclerosis (MS) patients. Gray matter (GM) atrophy and plaques have been attracting attention for various cognitive impairments in MS patients. This study aimed to clarify the atrophic GM regions associated with PM deficits and investigate the relationship between the atrophic GM regions and GM plaques. Methods Twenty-one MS patients and 10 healthy controls (HCs) underwent neuropsychological tests and MRI. PM was assessed using subtests of the Rivermead Behavioural Memory Test. A lesion symptom analysis was performed using voxel-based morphometry (VBM). We then evaluated GM plaques in the corresponding areas using double inversion recovery (DIR). Results MS patients showed lower PM scores than HCs (p=0.0064). The GM volume of MS patients tended to be lower than those of HCs. VBM analyses revealed correlations of the PM score with the orbital part of the left inferior frontal gyrus, the left hippocampus, and the right parahippocampus. There was no GM plaque in the orbital part of the left inferior frontal gyrus and the right parahippocampus. Only one patient (4.8%) had GM plaque in the left hippocampus. Conclusion The left inferior frontal gyrus, the left hippocampus, and the right parahippocampus were associated with PM in MS, whereas these atrophic GM regions were not associated with GM plaque. Regardless of the location of plaques on DIR, both PM deficit and GM atrophy should be detected using neuropsychological tests and VBM in MS patients.
Insights
Prospective memory (PM) deficits in multiple sclerosis (MS) are linked to atrophy in specific brain regions, not gray matter plaques. Early detection of PM decline and brain atrophy is crucial for MS patients.
Area of Science:
- Neuroscience
- Cognitive Neurology
- Neuroimaging
Background:
- Prospective memory (PM) is vital for daily functioning and is frequently impaired in multiple sclerosis (MS).
- Gray matter (GM) atrophy and lesions are implicated in cognitive deficits in MS patients.
- Understanding the neural correlates of PM deficits in MS is essential for targeted interventions.
Purpose of the Study:
- To identify specific atrophic gray matter (GM) regions associated with prospective memory (PM) deficits in multiple sclerosis (MS).
- To investigate the relationship between these atrophic GM regions and the presence of GM plaques in MS patients.
Main Methods:
- Neuropsychological tests (Rivermead Behavioural Memory Test) and MRI scans were administered to 21 MS patients and 10 healthy controls (HCs).
- Voxel-based morphometry (VBM) was used for lesion-symptom mapping to correlate PM performance with GM volume.
- Gray matter (GM) plaques were assessed in relevant areas using double inversion recovery (DIR) imaging.
Main Results:
- MS patients exhibited significantly lower PM scores compared to HCs (p=0.0064).
- VBM analysis revealed significant correlations between PM scores and reduced GM volume in the left inferior frontal gyrus (orbital part), left hippocampus, and right parahippocampus.
- GM plaques were largely absent in the identified atrophic regions, with only one patient showing a plaque in the left hippocampus.
Conclusions:
- Atrophy in the left inferior frontal gyrus, left hippocampus, and right parahippocampus is associated with PM deficits in MS, independent of GM plaque location.
- Neuropsychological testing and VBM are recommended for detecting PM deficits and GM atrophy in MS, irrespective of lesion imaging findings.
