Cerebral Microbleeds and Disability in Multiple Sclerosis Patients

Cerebral microbleeds are associated with an increased risk of physical and cognitive disability in multiple sclerosis (MS) patients, a recent study found.

The study, published in Radiology, is among the first to examine the effects cerebral microbleeds may have on clinical outcomes in MS. Cerebral microbleeds are leaky blood vessels in the brain that are a known risk factor for dementia.

Microbleeds become more common with age, and have been associated with Alzheimer’s disease, Parkinson’s disease, stroke, and traumatic brain injury. Researchers decided to examine MS and cerebral microbleeds after they observed a significant overlap in the risk factors for each condition.

“Our hypothesis was that there is increased prevalence of cerebral microbleeds in MS because progression of that disease is associated with increased likelihood of cardiovascular comorbidities, including hypertension, altered lipid metabolism, overweight/obesity, smoking and diabetes and migraine, all risk factors for cerebral microbleeds,” said first study author Robert Zivadinov, MD, PhD.

Researchers enrolled 445 patients with MS into the study, 45 of whom had clinically isolated syndrome, 51 who had other neurological diseases, and 177 healthy controls. All participants were required to undergo susceptibility-weighted imaging specifically targeted to image blood products.

The results of the study revealed that 20% of MS patients over 50-years-old had cerebral microbleeds compared with 7% of healthy controls. For patients under 50-years-old, 14% with clinically isolated syndrome had microbleeds, compared with just 3% of the healthy controls.

Researchers found that the more cerebral microbleeds a patient has, the more severe their physical and cognitive outcomes were.

In regards to physical disability, MS patients with a higher amount of cerebral microbleeds had more physical disability after adjusting for whole-brain volume, hypertension, and age.

“This is significant because it suggests that cerebral microbleeds are associated with increased physical disability in MS patients, independent from these additional risk factors for cerebral microbleeds,” Zivadinov said.

For cognitive disability, researchers found that the group of MS patients who received neuropsychological testing and had more cerebral microbleeds showed increased disability on verbal and cognitive function tests.

“Those MS patients who have cerebral microbleeds are subject to developing more physical and cognitive disabilities earlier in their disease, and therefore monitoring them more closely might be appropriate,” Zivadinov said.

Currently, researchers are conducting a 5-year longitudinal study of these patients primarily focused on the relationship between cerebral microbleeds, clinical outcomes, and advances in magnetic resonance imaging.