MRI and disability scores better predict RRMS cognitive decline than blood tests

In stable relapsing-remitting multiple sclerosis (RRMS), higher physical disability scores and brain volume loss on MRI are stronger indicators of cognitive impairment than common blood biomarkers. A new study found that while blood tests often fail to reflect mental decline, MRI scans and standard disability tests can successfully identify patients struggling with memory and information processing.

Researchers found that patients with cognitive impairment experienced more rapid brain tissue loss and smaller volumes in key regions, such as the thalamus and hippocampus. These areas are essential for storing and retrieving information. Interestingly, the study showed that the standard physical disability scale, known as the Expanded Disability Status Scale (EDSS), performed just as well as expensive imaging in flagging these cognitive issues.

The study, “Cognition and fatigue in clinically stable multiple sclerosis: EDSS and MRI metrics outperform serum biomarkers,” was published in BMC Neurology. It suggests that consistent screening is vital for patients even when their disease appears stable. Because fatigue and memory problems often occur without new relapses, tracking brain volume and disability scores can provide a more accurate picture of a patient’s true condition.

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MS symptoms occur when the immune system attacks the protective coating of nerve fibers. While some treatments can reduce relapses — periods of new or worsening symptoms — their ability to prevent long-term disability is often limited, particularly because disability progression can occur independently of relapses.

Fatigue and cognitive impairment are two of the most common and frustrating symptoms for those with MS. However, it has long been a challenge for doctors to determine whether clinical tests, scans, or blood work best reflect these “invisible” symptoms in patients who seem otherwise stable.

To find answers, researchers evaluated 54 adults with RRMS, 70.4% of whom were women. RRMS is characterized by relapses interspersed with periods of remission, during which symptoms partially or completely ease and remain relatively stable. Even though nearly all participants (92.6%) were on disease-modifying treatments and showed no recent clinical progression, more than 20% still had active changes visible on their MRI scans.

The team used the Fatigue Scale for Motor and Cognitive Functions to measure physical and mental exhaustion. They found that nearly 40% of the patients had cognitive impairment, while more than half struggled with physical (55.6%) and mental fatigue (57.4%).

When comparing the data, the researchers noticed a clear trend. Patients with cognitive impairment had a significantly smaller thalamus (an area that relays signals in the brain), hippocampus (involved in memory), and overall brain volume. Meanwhile, two common blood biomarkers — neurofilament light chain and glial fibrillary acidic protein — showed no real difference between those with cognitive issues and those without.

While physical and mental fatigue were not clearly linked to MRI scans or blood biomarkers, they did correlate with cognitive performance. This means that patients who felt more fatigued generally performed worse on mental tasks and had higher scores on the physical disability scale.

The study concludes that while the EDSS correlates well with cognitive health, it does not provide much more information than what an MRI already reveals. The researchers emphasized that tracking annual brain volume loss is far more informative for a patient’s cognitive outlook than current blood tests.

Because these symptoms can worsen even when a patient feels stable, the researchers called for more systematic cognitive screening in clinics. They noted that larger studies with longer follow-up periods are needed to confirm their findings.