Quantification of Brain Atrophy in Early Multiple Sclerosis and Its Clinical Relevance

WOS: 000389744400005Objective Background: In multiple sclerosis (MS), axonal loss and neurodegeneration occurs early in disease course and may lead to irreversible neurological impairment. We aimed to investigate brain volume loss as an accurate measure of axonal loss and its clinical relevance in early MS. Methods: Twenty MS patients whose first symptoms beginning within the last 2 years were underwent a neurological examination included Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Functional Composite (MSFC). Cognitive status of patients was assessed with Paced Auditory Serial Addition Test (PASAT) and Rey Auditory Verbal Learning Test (RAVLT). For processing magnetic resonance imaging (MRI) data, region of interest technique (ROI) and JIM 4.0 software were established. Brain parenchymal fraction (BPF), cerebrospinal fluid (CSF) volume, gray and white matter volumes of brain was determined in MS patients and in control subjects. The relationship between MRI data and demographic, clinical variables was also evaluated. Results: In MS patients, the mean BPF value was significantly lower than controls. BPF also negatively correlated with the duration of disease. 27.3% of the patients have impairment by verbal memory processes tests. We didn't find significant correlation between BPF scores and cognitive performance, and also MSFC/EDSS scores. There was only significant correlation between PASAT scores and white matter volume. Conclusion: Measurement of BPF is a reliable method for brain atrophy that can be used in clinical practice and clinical trials. The atrophy beginning at the early phase of the disease might not cause clinical disability because of cortical reorganization and there might be individual threshold value of axon loss for clinical disability. In order to determine the clinical relevance of brain atrophy, longitudinal MRI studies with cognitive evaluation by comprehensive neurophysiological tests are needed