Neurorehabilitation for Multiple Sclerosis Patients with Emotional Dysfunctions

Abstract

Depression frequently develops in multiple sclerosis (MS) patients, exacerbating the manifestations of the disease and making its management challenging. To date, no consensus has been reached regarding effective treatments for these sufferers due to limited understanding regarding the underlying mechanisms responsible for emotional disorders that are highly comorbid with this disease. There is an urgent need to rethink current treatment options for these patients. This article aims to optimize the treatment outcomes and improve the quality of life for MS patients. Based on an in-depth and critical review of the current literature, we provide a neurorehabilitative framework that explains possible regulatory mechanisms underlying the emotional symptoms highly developed in MS. This article offers practical knowledge and therapeutic strategies to optimize the treatment options in the current care system for MS, as well as for other disabling diseases. Approximately half of all patients with multiple sclerosis (MS) experience clinically significant depression at least once in their lifetimes and even more exhibit emotional symptoms. The depressive disorders observed in MS exacerbate the manifestations of the disease and make its management challenging (1). Yet, the majority of MS patients with depressive symptoms receive neither antidepressant medication nor psychotherapy. The side effect profile of conventional antidepressant treatments can complicate MS management, compromising treatment efficacy and compliance (2). No consensus to date has been reached regarding effective treatment options for these sufferers, due to limited understanding regarding the underlying mechanisms that may be responsible for the emotional disorders that are highly comorbid with MS. There is therefore an urgent need for clinicians and neuroscientists to rethink current treatment options for these patients and improve the quality of their care. Here, we provide a neurorehabilitative framework that explains possible regulatory mechanisms underlying the emotional symptoms frequently developed in MS and suggest practical strategies to optimize its treatment outcomes. Patients with MS, a heterogeneous central nervous system disease causing focal brain lesions and diffuse demyelination, suffer from pronounced physical and cognitive disabilities (3). Though retaining their intellectual abilities, MS patients exhibit various cognitive deficits involving both verbal and non-verbal memory, attention and speed of processing, as well as executive functioning. The progression of MS introduces a chronic stress in patients, associated with impaired neurocognitive functions and diminished brain resources (cognitive reserve), which involve pathology of not only the cortex but also deep brain structures, including the limbic system. In particular, impaired brain connectivity in MS patients has been observed between the prefrontal lobe and the amygdale (4) – brain circuits important for the regulation of emotions (Figures 1A,B) (5). Deficits in executive functions also contribute to problems of impulsivity and lack of emotional control. Abnormal emotional processing takes place in the dysregulated brain with limited neurocognitive resources, and the MS patients experience negative attentional bias and use maladaptive cognitive appraisal toward daily life events. These cognitive deficiencies create a susceptibility to the development of emotional symptoms and disorders such as depression (Figures 1B,C). Neuroimaging evidence suggests that the depressive symptoms in MS are related to the total extent of brain lesions and the degree of impaired cortical-subcortical connections.Canadian Institutes of Health ResearchAthinoula A. Martinos Center for Biomedical ImagingSt. Michael's Hospital. Department of the Neurosurgery-Neuroscience Research