Feature ArticleCognitive Impairment in Multiple Sclerosis
Introduction
Jean-Martin Charcot, the first neurologist to describe the clinical and pathologic features of multiple sclerosis (MS) in the 19th century notes, “marked enfeeblement of the memory, conceptions formed slowly, and intellectual and emotional faculties blunted in their totality” as the earliest recording of cognitive difficulties associated with MS.1 One hundred forty years later, cognitive impairment is recognized as a common symptom of a central nervous system (CNS) disease that impairs nerve conduction in motor, sensory, and cognitive pathways.
Section snippets
Background
MS is a chronic disease of CNS myelin, the lipid covering that speeds nerve conduction. A dis-regulated immune system targets myelin for destruction and contributes to inflammation. The inflammatory response leads to scaring or lesions in the CNS and is expressed as motor, sensory, and cognitive/emotional symptoms. The average age at diagnosis is 31 years, with important economic and social implications in the young adult population.2 Prevalence of MS in the US, according to recent
Cognitive Impairment in MS
Approximately 70% of those with MS experience cognitive impairment. Cognitive difficulties occur at any time in the disease course and may be unrelated to disability or other demographic characteristics.5 However, a recent study found cognitive dysfunction to be more frequent and more severe in progressive phenotypes and those with greater disability.6 Disease progression, duration, and employment status, as well as symptoms of fatigue and depression, correlate more strongly with MS cognitive
Assessment
Assessments that are most objective include neuropsychological testing and functional magnetic resonance imaging (fMRI). The thalamus is an important connector and relay center to higher brain functions and regulates processing speed. The hippocampus is responsible for learning and memory and the prefrontal cortex regulates multitasking and executive control. Imaging studies are able to show and thereby correlated MS cognitive impairment with slowed signaling in these brain structures. As
Management
“I’ve received a poor performance review at work. They say I take too long to hand in assignments. I think the poor review is an excuse to get rid of me” (personal conversation, WF).
Poor incite into the nature of the problem is common. WF is at risk for losing his job. His company may want to “get rid of him.” His review indicated he was not doing the job to satisfaction. Cognitive deficits represent the greatest risk to continued employment. Fatigue and depression may also influence workplace
Summary
MS, a CNS disease typified by motor, sensory, and cognitive symptoms, affects nearly one million living in the US. A common symptom in over half of these patients is cognitive impairment, which has economic, social, and quality-of-life implication. Cognitive dysfunction relates to lesions in the CNS and can occur at any time in the disease trajectory, affecting young and older MS patients alike. Information processing is the most prevalently affected domain and is assessed in the clinic or at
Heidi Maloni, PhD, ANP-BC, is national clinical nursing director at the Multiple Sclerosis Center of Excellence, East Veterans Affairs Medical Center, Department of Neurology in Washington, DC; she can be reached at [email protected].
References (39)
Cognitive functioning in multiple sclerosis
Neurol Clin
(2011)- et al.
Thalamic atrophy predicts cognitive impairment in relapsing remitting multiple sclerosis. Effect on instrumental activities of daily living and employment status
J Neurol Sci
(2015) - et al.
Efficacy and safety profile of memantine in patients with cognitive impairment in multiple sclerosis: a randomized controlled study
J Neurol Sci
(2016) Lectures on the diseases of the nervous system
(1877)- et al.
Epidemiology of multiple sclerosis: from risk factors to prevention-an update
Semin Neurol
(2016) - Wallin MT, Culpepper WJ, Campbell J, et al. United States MS Prevalence Workgroup. The prevalence of MS in the United...
- et al.
Defining the clinical course of multiple sclerosis. The 2013 revisions
Neurology
(2014) - et al.
Cognitive impairment in a population-based study of patients with multiple sclerosis: differences between late relapsing-remitting, secondary progressive and primary progressive multiple sclerosis
Eur J Neurol
(2016) - et al.
BICAMS in the Argentinian population: relationship with clinical and socioeconomic variables
Appl Neuropsychol Adult
(2017) - et al.
Neuropsychological, medical and rehabilitative management of persons with multiple sclerosis
NeuroRehabilitation
(2011)
Cognitive impairment in multiple sclerosis-a review of current knowledge and recent research
Rev Neurosci
Cognitive impairment in multiple sclerosis: clinical, radiologic and pathologic insights
Brain Pathol
The sensitivity of the mini-mental status exam in the white matter dementia multiple sclerosis
J Clin Psychol
Brief international cognitive assessment for MS (BICAMS): international standards for validation
BMC Neurol
Quality measures in neurology: multiple sclerosis quality measures
Neurology
Cognition in multiple sclerosis
Curr Opin Neurol
Validity of the symbol digit modalities test as a cognition performance outcome measure for multiple sclerosis
Mult Scler J
Effects of acute relapse on neuropsychological status in multiple sclerosis patients
J Neurol
Symbol digits modalities test
Cited by (10)
Efficacy of non-invasive brain stimulation on cognitive functioning in brain disorders: A meta-Analysis
2020, Psychological MedicineP300 event-related potentials in patients with multiple sclerosis
2023, Egyptian Journal of Neurology, Psychiatry and NeurosurgeryAnomia in left hemisphere stroke, multiple sclerosis and Parkinson’s disease–a comparative study
2023, Disability and RehabilitationThalamic atrophy, duration of illness, and years of education are the best predictors of cognitive impairment in multiple sclerosis
2022, Clinical and Experimental NeuroimmunologyAssessment of cognitive functions in patients with multiple sclerosis
2021, Egyptian Journal of Neurology, Psychiatry and Neurosurgery
Heidi Maloni, PhD, ANP-BC, is national clinical nursing director at the Multiple Sclerosis Center of Excellence, East Veterans Affairs Medical Center, Department of Neurology in Washington, DC; she can be reached at [email protected].
In compliance with national ethical guidelines, the author reports no relationship with business or industry that would pose a conflict of interest.