Online Assessments Reveal a Common Subtype of Multiple Sclerosis with Hidden Cognitive Challenges

Recent research conducted by King's College London and Imperial College London, in collaboration with the UK MS Register, has identified a prevalent subtype of multiple sclerosis (MS) characterized by significant cognitive impairments despite minimal motor symptoms. This form of MS has traditionally gone unrecognized and untreated because typical evaluations emphasize physical disability, leaving cognitive deficits unnoticed.

Cognitive issues in MS are highly common, affecting between 40% and 70% of patients at various stages of the disease. These impairments often impact work ability and overall quality of life more profoundly than physical disabilities. However, standard neuropsychological tests are either lengthy or too narrowly focused, making routine assessment of cognition unfeasible in many settings. As a result, cognition is frequently excluded from disease phenotyping, leading to gaps in understanding its true prevalence and severity.

To address this challenge, researchers developed and deployed an automated online assessment tool to evaluate cognitive function across a large MS population. This approach aimed to identify distinct symptom-based MS phenotypes on a broad scale. The study involved 4,526 participants from the UK MS Register, who took part in three stages. The first stage tested 19,188 registrants with 22 online tasks designed to differentiate MS from other conditions. After analyzing effect sizes and device sensitivity, a core battery of 12 tasks was selected for further testing.

In the second stage, the 12-task battery was administered to a new cohort along with additional memory tasks, confirming the tool's ability to detect cognitive deficits. The third stage compared this online assessment with comprehensive in-person neuropsychological testing for 31 patients, further validating its effectiveness.

The online testing was user-friendly, with over 70% of participants completing the assessments in about 40 minutes. When combining online cognitive scores with motor function questionnaires, four distinct groups emerged:

1. Minimal Motor Symptoms + Moderate Cognitive Impairment: Little movement difficulty but notable issues with memory, reasoning, and attention.
2. Minimal Motor Symptoms + No Cognitive Impairment: Little movement difficulty and generally intact cognition, with only minor slowed performance on a single task.
3. Severe Motor Symptoms + Mild Cognitive Problems: Significant movement issues with only mild cognitive difficulties.
4. Severe Motor Symptoms + Severe Cognitive Impairment: Prominent movement issues alongside broad cognitive deficits.

Further comparison of the online tests with traditional clinic assessments showed strong agreement in cognitive classification, indicating that this automated approach can reliably detect the presence of cognitive impairment. Notably, the study revealed a common MS subtype characterized by weak motor symptoms but significant cognitive problems, which standard evaluations often miss.

This research underscores the potential of large-scale, automated online assessments to improve understanding of MS phenotypes and facilitate earlier, targeted interventions for cognitive issues that significantly affect daily life and disease management.

Source: https://medicalxpress.com/news/2025-09-online-uncovers-common-multiple-sclerosis.html