Researchers Study Brain Atrophy of Aging MS Patients

The study, the first that compares brain changes among age-matched healthy controls and older patients who have MS, Alzheimer’s disease, Parkinson’s disease or amnestic mild cognitive impairment (amnestic MCI) — which primarily affects only memory — was published Feb. 8 in the journal Neurobiology of Aging.

In addition, the increased longevity of patients with multiple sclerosis — which also causes neurodegeneration and brain atrophy — has highlighted the need to understand the differences among these neurological conditions.

“This study is a first step in comparing patterns of brain atrophy and determining which brain regions are vulnerable and may accelerate during the aging process,” says first author Dejan Jakimovski, MD, a student in the doctoral program in neuroscience. “We are using MRI to begin to uncover some structural features that may distinguish how this symptom develops in these different diseases.” 

More than 400 people participated. Almost half of them were healthy controls, more than a quarter were MS patients and the rest had Alzheimer’s, Parkinson’s or amnestic MCI. All underwent structural MRI, which noninvasively reveals the anatomy and pathology of the brain.

“One of the goals of the study was to identify certain structural MRI features that could help us better understand the newly emerging cognitive deficits seen in aging MS patients,” Jakimovski says. 

He noted that as they age, MS patients dealing with the progressive disease experience daily difficulties with cognitive functioning. As their neurodegeneration accelerates, their cognitive difficulties may worsen.

“Therefore, greater awareness of their cognitive abilities and the risk for future decline indicate that MS patients need baseline cognitive and MRI testing. They should also communicate with their neurologists and neuropsychologists about cognitive changes that they notice,” Jakimovski says.

The researchers weren’t surprised to find that the most significant factor that differentiated the brains of MS patients from other participants was the extent of white matter volume atrophy. 

“Pathology within the white matter of the brain is specific to MS patients,” says senior author Robert Zivadinov, MD, PhD, professor of neurology in the Jacobs School and director of its Buffalo Neuroimaging Analysis Center (BNAC) and the Center for Biomedical Imaging at UB’s Clinical and Translational Science Institute. “These inflammatory lesions affect the axons — the brain’s main highways for information — and their disruption significantly decreases the speed and efficacy of information processing.”

He added that the cognitive function most commonly associated with the progression of MS is the slowing down of cognitive processing — the ability to efficiently accomplish a mental task.

A more significant finding emerged in the comparison between MS patients and those with Alzheimer’s.

“We were surprised to see that MS patients have low brain volume that is comparable to that seen in Alzheimer’s disease,” Jakimovski says.

While researchers caution that this is the first cross-sectional comparison — examining differences among these patients at one point in time — they noted that future longitudinal studies that determine the specific rate of brain atrophy in MS are needed.

“Whether or not this implies that MS patients might be at higher risk to develop Alzheimer’s is unclear,” Zivadinov says. 

“As the first-of-its-kind, our study may increase the awareness of a potential Alzheimer’s-associated pathology among MS patients,” Zivadinov adds. “We urge clinicians to screen their aging MS patients for Alzheimer’s disease-related cognitive changes.”

Other co-authors from the Department of Neurology are:

• Ralph H. Benedict, PhD, professor  
• Niels P. Bergsland, PhD, research assistant professor
• Michael G. Dwyer III, PhD, assistant professor
• Thomas J. Guttuso Jr., MD, professor
• David W. Hojnacki, MD, associate professor
• David G. Lichter, MBChB, clinical professor
• Kinga Szigeti, MD, PhD, associate professor
• Bianca Weinstock-Guttman, MD, professor

Weinstock-Guttman is also director of the Jacobs Multiple Sclerosis Center for Treatment and Research at UBMD Neurology. Dwyer is also an assistant professor of biomedical informatics.

Other co-authors are:

• Jesper Hagemeier, PhD, senior biostatistician and research scientist at BNAC
• Deepa Preeti Ramasamy, MD, clinical trial neuroimager at BNAC

The research was funded by the National Center for Advancing Translational Sciences of the National Institutes of Health.