Thalamic-hippocampal-prefrontal disruption in relapsing-remitting multiple sclerosis

Kyle C. Kern, Stefan M. Gold, Brian Lee, Michael Montag, Jessica Horsfall, Mary-Frances O'Connor, Nancy L. Sicotte

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

Background Cortical, thalamic and hippocampal gray matter atrophy in relapsing-remitting MS (RRMS) is associated cognitive deficits. However, the role of interconnecting white matter pathways including the fornix, cingulum, and uncinate fasciculus (UF) is less well studied. Objective To assess MS damage to a hippocampal-thalamic-prefrontal network and the relative contributions of its components to specific cognitive domains. Methods We calculated diffusion tensor fractional anisotropy (FA) in the fornix, cingulum and UF as well as thalamic and hippocampal volumes in 27 RRMS patients and 20 healthy controls. A neuropsychological battery was administered and 4 core tests known to be sensitive to MS changes were used to assess cognitive impairment. To determine the relationships between structure and cognition, all tests were grouped into 4 domains: attention/executive function, processing speed, verbal memory, and spatial memory. Univariate correlations with structural measures and depressive symptoms identified potential contributors to cognitive performance and subsequent linear regression determined their relative effects on performance in each domain. For significant predictors, we also explored the effects of laterality and axial versus radial diffusivity. Results RRMS patients had worse performance on the Symbol Digit Modalities Test, but no significant impairment in the 4 cognitive domains. RRMS had reduced mean FA of all 3 pathways and reduced thalamic and hippocampal volumes compared to controls. In RRMS we found that thalamic volume and BDI predicted attention/executive function, UF FA predicted processing speed, thalamic volume predicted verbal memory, and UF FA and BDI predicted spatial memory. Conclusions Hippocampal-thalamic-prefrontal disruption affects cognitive performance in early RRMS with mild to minimal cognitive impairment, confirming both white and gray matter involvement in MS and demonstrating utility in assessing functional networks to monitor cognition.

Original languageEnglish (US)
Pages (from-to)440-447
Number of pages8
JournalNeuroImage: Clinical
Volume8
DOIs
Publication statusPublished - Jun 8 2015

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Keywords

  • Cognition
  • Diffusion tensor imaging
  • Limbic system
  • Memory
  • MRI
  • Multiple sclerosis

ASJC Scopus subject areas

  • Clinical Neurology
  • Radiology Nuclear Medicine and imaging
  • Cognitive Neuroscience
  • Neurology

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