Is there a link between multiple sclerosis and Alzheimer disease? A critical note

Area of Science:

• Neuroscience
• Immunology
• Genetics

Background:

• Multiple sclerosis (MS) and Alzheimer disease (AD) are significant neurological disorders impacting quality of life.
• Increased prevalence of AD in elderly MS patients is linked to extended lifespans and shared pathogenetic mechanisms.
• Cognitive dysfunction affects 40-60% of MS patients, yet the co-occurrence and relationship between MS and AD are not well understood.

Purpose of the Study:

• To review the existing literature on the overlaps between Alzheimer disease and multiple sclerosis.
• To explore the shared pathophysiological processes contributing to the development of AD pathology in MS patients.

Main Methods:

• Literature review of approximately 125 cases of comorbid MS and AD.
• Analysis of genetic, environmental, and molecular mechanisms implicated in both diseases.

Main Results:

• Both MS and AD share genetic and environmental risk factors, including Epstein-Barr virus infection.
• Evidence suggests overlapping pathobiology, including amyloid pathology and impaired Aβ metabolism.
• Similar patterns of microglial activation and neuroinflammation are observed in both conditions.

Conclusions:

• Shared mechanisms such as immune dysfunction, inflammation, and neurodegeneration contribute to the co-occurrence of MS and AD.
• Demyelination, amyloid dysfunction, blood-brain barrier damage, and mitochondrial impairment are key factors in neurodegeneration.
• Understanding these overlaps is crucial for managing cognitive decline in patients with advanced MS.