How Multiple Sclerosis Affects the Brain and CNS

The damage done today can have devastating effects decades later.

When Dr. Timothy Vollmer sees patients with multiple sclerosis (MS), they talk about the symptoms they are experiencing today. But Vollmer tries to get them thinking further down the road. Most people with MS are diagnosed between the ages of 20 and 40, but might not feel the full impact of the disease until their 60s.

“The best bet at slowing the progression of disability later in life is at the beginning of the disease,” said Vollmer, a neurologist at the University of Colorado Denver. “But many patients — and even neurologists — don’t fully understand how MS affects the brain over a lifetime and why brain preservation is important.”

The Death of the Neurons

DR. TIMOTHY VOLLMER FROM THE UNIVERSITY OF COLORADO DENVER BELIEVES THAT THE BEST WAY TO SLOW DISABILITY PROGRESSION LATER IN LIFE IS TO TREAT MULTIPLE SCLEROSIS EARLY.

DR. TIMOTHY VOLLMER FROM THE UNIVERSITY OF COLORADO DENVER BELIEVES THAT THE BEST WAY TO SLOW DISABILITY PROGRESSION LATER IN LIFE IS TO TREAT MULTIPLE SCLEROSIS EARLY.

Damage in the brain for patients with MS is driven at least in part by a critical component of the immune system called B lymphocytes, also known as B cells, which recruit other immune cells and cause an inflammatory reaction. Why B cells begin attacking neurons is not fully understood, but what can be clearly seen is the damage they leave behind in the form of lesions that appear as bright white spots on a patient’s magnetic resonance imaging (MRI) scan.

When Vollmer analyzes a patient’s MRI, he pays particular attention to the appearance of lesions in the grey matter of the brain, the region involved in muscle control and sensory perception. As the grey matter continues to be attacked, causing new lesions to develop, symptoms such as fatigue and memory loss become more common, and cognitive impairment tends to increase.

But lesions often don’t appear steadily and consistently throughout a patient’s lifetime. Instead, the number of lesions tends to be highest at the onset of MS and then decreases over time. By the time a person with MS reaches 60 years old, new lesions are relatively rare.

“We don’t know why these lesions appear to decrease over time,” Vollmer said. “But if we wait to treat patients, the damage has already been done and what we’re left with is an accelerated pace of brain volume loss.”

Neurological Reserve

By the age of 40, everyone’s brain begins shrinking due to the loss of neurons as a result of the normal aging process. However, brain shrinkage happens faster in people with MS; while healthy individuals lose 0.1 to 0.5 percent of their brain volume per year, people with MS lose 0.5 to 1.35 percent per year, a significantly faster rate than those without the disease.

It’s important that neurologists understand how MS affects the brain throughout a person’s lifetime.

The effects of this brain volume and neuron loss may not be immediately apparent, though, because their brains and central nervous system tap into a neurological reserve to supplement this decline. However, those reserves are then used up sooner and, coupled with the normal aging process, result in the increased cognitive impairment and disability seen in people with MS.

With this long-term understanding of how MS affects the brain and CNS, Vollmer is traveling to conferences, giving lectures and trying to drive an international consensus on the issue. He’s reminding his patients and colleagues that it’s important to focus on measuring not only relapses, but also lesions and brain volume loss.

“It’s important that neurologists understand how MS affects the brain throughout a person’s lifetime,” Vollmer said. “Then they will understand why treating patients early and encouraging healthy lifestyles is essential to improving their patients’ lives down the line.”

To learn more about the MS journey for patients, read “The Search Continues for More Multiple Sclerosis Treatment Options.”