Cognitive impairment, fatigue and depression in multiple sclerosis: Is there a difference between benign and...

Area of Science:

• Neurology
• Neuroscience
• Clinical Medicine

Background:

• Multiple Sclerosis (MS) is a chronic CNS disease impacting disability, often measured by the Expanded Disability Status Scale (EDSS).
• Benign MS (BMS) is defined by low EDSS scores (≤3) and long disease duration (≥10 years), but its existence and definition are debated.
• The EDSS may not adequately assess cognitive function, fatigue, depression, or anxiety in people with MS (PwMS).

Purpose of the Study:

• To investigate the prevalence of cognitive impairment, fatigue, and depression in individuals meeting the EDSS-based definition of benign MS (BMS).
• To compare these outcomes in PwBMS with those in PwMS with non-benign MS (PwNBMS) and shorter disease duration.
• To evaluate the adequacy of the current EDSS-based definition of BMS.

Main Methods:

• 141 individuals with BMS (PwBMS) and 158 with non-benign MS (PwNBMS) (≥10 years duration, EDSS >3) were assessed.
• Cognitive function was evaluated using the NeuroTrax® computerized test battery across seven domains.
• Fatigue was measured by the Fatigue Severity Scale (FSS), and depression by the Beck Depression Inventory (BDI).

Main Results:

• Cognitive impairment affected 38% of PwBMS compared to 66% of PwNBMS (p<0.001).
• Information processing (32%) and verbal function (18%) were the most and least affected cognitive domains in PwBMS, respectively.
• Fatigue (78%) and depression (55%) were highly prevalent in PwBMS, with no significant difference compared to PwNBMS.

Conclusions:

• Cognitive impairment, fatigue, and depression are prevalent in individuals classified with benign MS based on EDSS.
• The current EDSS-based definition of benign MS may be insufficient to capture the full spectrum of disability.
• A revised definition of benign MS should incorporate cognitive, fatigue, and mood assessments for a more accurate representation.