Cognitive Dysfunction in MS: Bridging the Gap Between Neurocognitive Deficits, Neuropsychological Batteries and MRI

Adapted from reference 8.

BVMT-R: Brief visuospatial memory test - revised; CVLT-II: California verbal learning test-II; DR: Delayed recall; L: Left; PASAT: Paced auditory serial addition test; R: Right; SDMT: Symbol digit modalities test; TL: Total learning
Adapted from reference 59.

BVMT-R: Brief visuospatial memory test - revised; COWAT: Controlled oral word association test; CVLT-II: California verbal learning test-II; D-KEFS: Delis-Kaplan Executive Function System; DWI: Diffusion-weighted imaging; FLAIR: Fluid-attenuated inversion recovery; fMRI: Functional MRI; JLO: Judgment of line orientation test; MTI: Magnetization transfer imaging; MTR: Magnetization transfer ratio; PASAT: Paced auditory serial addition test; PVSAT: Paced visual serial addition test; QMRI: Quantitative MRI; SDMT: Symbol digit modalities test.

Authors and Disclosures

Erica Grazioli, Ann E Yeh, Ralph HB Benedict, Joy Parrish, Bianca Weinstock-Guttman, Jacobs Neurological Institute, Baird Multiple Sclerosis Center, Buffalo, NY

Sidebar: Executive Summary

Introduction

• More than 50% of multiple sclerosis (MS) patients have some degree of cognitive dysfunction, even in the early stages of the disease.
  
  

• The most frequent areas of cognitive impairment in MS are memory, attention, information processing, abstract/conceptual reasoning and visuospatial skills. Semantic knowledge, information storage, encoding and short-term memory are typically preserved in MS. Long-term memory is often impaired.

Cognitive Batteries & Screening

• The minimal assessment of cognitive function in MS is a consensus of a core battery of seven neuropsychological tests to evaluate cognitive functioning.
  
  

• Brief cognitive screenings validated in MS include the symbol digit modalities test and MS neuropsychological screening questionnaire (MSNQ).
  
  

• The MSNQ can be administered without clinical staff. Companion reports on the MSNQ correlate with cognitive dysfunction to a higher degree than do self reports, which correlate with both depression and cognition.

Imaging & Relationship to Cognitive Function

• Third ventricle width accounts for more variance in cognitive function in MS than MRI lesion volumes.
  
  

• Correlations are found between specific gray matter volumes involving the cerebral cortex and cognitive test results.
  
  

• Significant correlations exist between diffusion-weighted imaging and entropy in MS patients and cognitive impairment in the domains of memory, learning, attention and executive function.

Genetics

• Genetic markers, such as ApoE and BDNF polymorphisms, have been found to correlate with cognition.

Treatment

• Early treatment with disease-modifying therapies may reduce cognitive impairment or slow down the progression of cognitive deficits.
  
  

• Symptomatic treatment with cholinergic agents (i.e., donepezil) or gingko biloba may have some benefits on learning, memory and fatigue.
  
  

• Specific cognitive rehabilitation should be considered as part of a comprehensive MS treatment strategy.

Future Perspective

• Therapeutic intervention for cognitive dysfunction should include: disease-modifying therapies, symptomatic therapies, rehabilitation and psychotherapy measures.
  
  

• Future improvements in neuropsychological batteries in parallel with the development of more sensitive neuroimaging techniques represent two of the most important goals in MS research as part of the crusade to cure MS.