Fatigue in Multiple Sclerosis Could be Pinpointed to Brain Region

Regional damage in the brain could be the main contributing factor to fatigue, a symptom of multiple sclerosis (MS), according to research published in Radiology.

Researchers from Vita-Salute San Raffaele University in Italy studied 65 MS patients, of which 31 were fatigued and 32 were nonfatigued. An additional 35 control patients were included in the study.

According to the National MS Society, fatigue occurs in about 80% of patients with MS. Although sleep deprivation is a main component of MS fatigue, researchers believe there is an MS-specific type of fatigue, known as lassitude.

Generally, lassitude occurs on a daily basis, may occur even after a restful night’s sleep, gets worse as the day progresses, is aggravated by heat and humidity, comes on suddenly or easily, is usually more severe than normal fatigue, and is more likely to interfere with daily responsibilities.

As a result of these and other symptoms, daily tasks and responsibilities, such as dressing, brushing teeth, bathing, and preparing meals, that require considerable effort may be signs of a fatigued patient.

After local ethics committees approved the study and written consent forms were obtained, participants underwent dual-echo, double inversion recovery, high-resolution T1-weighted and diffusion-tensor magnetic resonance imaging (MRI). The researchers measured the degree of atrophy and compared damage to lesions, normal-appearing white matter, and gray matter among the different groups.

In both sets of MS patients, there was more damage present to grey and white matter when compared to the control participants. However, fatigued MS patients showed changes in specific regions of the brain when compared to their nonfatigued counterparts.

Using the Fatigue Severity Scale, researchers examined the fatigued patients’ right nucleus accumbens, right inferior temporal gyrus, and left frontal gyrus. Researchers found these sectors were associated with fatigue. Fatigued patients, they said, showed more damage in the forceps major, left inferior frontoccipital fasciculus, and right anterior thalamic radiation as well.

The researchers were also able to predict fatigue in the patients by using the right inferior temporal gyrus and the right anterior thalamic radiation damage.

“Damage to strategic brain white matter and grey matter regions, in terms of microstructural abnormalities and atrophy, contributes to pathogenesis of fatigue in MS, whereas global lesional, white matter, and grey matter damage does not seem to have a role,” the researchers concluded. “This study supports the use of multimodal magnetic resonance imaging and regional analysis to assess fatigue in patients with MS.”

The researchers said their next step is to create longitudinal studies to offset the limitations of the present work. They reported wanting to use MRIs to define a pathogenetic link between atrophy and fatigue severity.