Subgroup Analysis of Individuals with Multiple Sclerosis Showing Cognitive Resilience

Cognitive impairment in multiple sclerosis: from phenomenology to neurobiological mechanisms

Multiple sclerosis (MS) is an autoimmune-mediated disease of the central nervous system characterized by inflammation, demyelination and chronic progressive neurodegeneration. Among its broad and unpredictable range of clinical symptoms, cognitive impairment (CI) is a common and disabling feature greatly affecting the patients' quality of life. Its prevalence is 20% up to 88% with a wide variety depending on the phenotype of MS, with highest frequency and severity in primary progressive MS. Involving different cognitive domains, CI is often associated with depression and other neuropsychiatric symptoms, but usually not correlated with motor and other deficits, suggesting different pathophysiological mechanisms. While no specific neuropathological data for CI in MS are available, modern research has provided evidence that it arises from the disease-specific brain alterations. Multimodal neuroimaging, besides structural changes of cortical and deep subcortical gray and white matter, exhibited dysfunction of fronto-parietal, thalamo-hippocampal, default mode and cognition-related networks, disruption of inter-network connections and involvement of the γ-aminobutyric acid (GABA) system. This provided a conceptual framework to explain how aberrant pathophysiological processes, including oxidative stress, mitochondrial dysfunction, autoimmune reactions and disruption of essential signaling pathways predict/cause specific disorders of cognition. CI in MS is related to multi-regional patterns of cerebral disturbances, although its complex pathogenic mechanisms await further elucidation. This article, based on systematic analysis of PubMed, Google Scholar and Cochrane Library, reviews current epidemiological, clinical, neuroimaging and pathogenetic evidence that could aid early identification of CI in MS and inform about new therapeutic targets and strategies.

Integrating Lifestyle Factor Science into Neuropsychological Practice: A National Academy of Neuropsychology Education Paper

OBJECTIVE

The primary aim of this paper is to review evidence and clinical implications related to lifestyle activities associated with promoting brain and cognitive health. Our review targets four key lifestyle factors: physical activity and exercise, social engagement, cognitively stimulating activity, and consuming Mediterranean-style diets.

METHOD

We conducted a critical review of the lifestyle factor literature in the four domains listed earlier. We contextualize this literature review by translating findings, when possible, into evidence-based recommendations to consider when providing neuropsychological services.

RESULTS

There is significant current evidence supporting the role of physical activity and exercise, social engagement, cognitively stimulating activity, and consuming Mediterranean-style diets on positive brain and cognitive health outcomes. While some null findings are present in all four areas reviewed, the weight of the evidence supports the notion that engaging in these activities may promote brain and cognitive functioning.

CONCLUSIONS

Clinical neuropsychologists can have confidence in recommending engagement in physical activity, social activity, and cognitively stimulating activity, and adhering to a Mediterranean-style diet to promote brain and cognitive health. We discuss limitations in existing lifestyle factor research and future directions to enhance the existing evidence base, including additional research with historically underrepresented groups and individuals with neurological conditions.