Cognitive Decline and Treatment Strategies in Multiple Sclerosis Patients

Effrosyni Koutsouraki

doi:10.31487/j.nnb.2020.03.04

Abstract

Multiple Sclerosis (MS) is an autoimmune disease of the Central Nervous System (CNS), mainly appeared in young adults, characterized by neuroinflammation, demyelination, neurodegeneration and remyelination and with a variety of CNS-related symptoms. The prevalence of cognitive decline in MS patients has been reported to range widely, from 13% to 72%, occurring in all stages of the disease, and can lead to mental disability, social impairment, and an impoverished quality of life. The pathogenetic mechanism of the cognitive decline in MS has yet to be revealed, and, thus, we are still unable to predict which patients are more likely to manifest such a decline and at what stage of the disease. Clinical factors, including the type and the course of the disease, but also fatigue and emotional disturbances, can impact the degree of MSrelated cognitive impairment. It has been reported that almost 40% of the MS patients demonstrate a significant deficit in recognizing and recalling verbal and visual memories, either at the onset of the disease or at its later stages, whereas short-term memory remains almost intact. Many patients also demonstrate deficits in complex attention, a slower efficiency in information processing, a declined ability of problemsolving, planning, and prioritization tasks or even visual agnosia and aphasia. Most of the MS-specific disease-modifying treatments seem to reduce the rate of MS attacks and slower the progression; however, their impact on cognitive impairment remains unclear. We propose that cognitive function evaluations should be incorporated in the regular assessment and monitoring of MS patients since they seem to be well correlated with the progression of the disease. Even if the effect of the neuropsychological batteries used for diagnostic and therapeutic purposes still remains very much limited, especially due to the validation and standardization issues, specific cognitive functions treatment strategies should be implemented in the therapeutic scheme of MS patients.

Highlights

Multiple Sclerosis (MS) is an autoimmune demyelinating and neurodegenerative disease of the Central Nervous System (CNS), mainly appeared in young adults, usually being diagnosed in their 3rd or 4th decade of their life and lasting for the rest of their life
Kyriakidi Street, 546 21, Thessaloniki, Greece; Tel: 00306977532465; Fax: 00302310994711; E-mail: efrosink@gmail.com slower efficiency in information processing. Many researchers believe the latter to be due to poor working memory, which has been linked to general dysfunction of cognitive processes, while others support that is due to purely motor deficits [7, 8]
Visual-spatial and speech impairment have been studied to a lesser extent due to sensory, motor and visual deficits, which are commonly manifested in MS patients and are highly dependent on the disease-related progression [2]

Summary

Introduction

Multiple Sclerosis (MS) is an autoimmune demyelinating and neurodegenerative disease of the Central Nervous System (CNS), mainly appeared in young adults, usually being diagnosed in their 3rd or 4th decade of their life and lasting for the rest of their life. Other studies have shown a disability in problem-solving, planning, and prioritization of tasks [9, 10] Such problems seem to affect up to 19% of MS patients and they are most likely related to damage to the prefrontal circuits [11, 12]. Many studies do not demonstrate any significant correlation between cognitive impairment and physical disability or the progression and duration of MS [15]. Some authors claim these impairments to be more common in the progressive type of MS, rather than its relapsing [16]. The aforementioned evidence offers an explanation as to why we still have not found the neuroanatomical basis and the pathogenetic mechanisms of the cognitive decline, and, we are still unable to predict the patients who are more likely to manifest such decline and at what stage of the disease [17, 2123]

Pharmacological Interventions i MS-Specific Disease-Modifying Treatments

Findings

Conclusion