Fatigue in Multiple Sclerosis Linked to Regional Brain Damage
Fatigue, a common symptom of multiple sclerosis, could be a result of regional damage in the brain. A study published in Radiology by a group in Italy led by Massimo Filippi, MD, from Vita-Salute San Raffaele University showed that local, rather than global, atrophy is associated with fatigue.
Sixty five patients with multiple sclerosis, 31 fatigued and 32 nonfatigued, and 35 control participants were analyzed with a specialized type of brain scan: dual-echo, double inversion-recovery, high-resolution T1-weighted and diffusion-tensor magnetic resonance imaging. The degree of atrophy and damage to lesions, normal-appearing white matter, and gray matter were compared among groups.
Between both types of multiple sclerosis patients and control participants, there was more global damage to gray and white matter in multiple sclerosis patients. But compared to nonfatigued patients and control participants, fatigued multiple sclerosis patients had remarkable changes in specific regions of the brain. Regional atrophy in the right nucleus accumbens, right inferior temporal gyrus, and left frontal gyrus was associated with fatigue, measured by the Fatigue Severity Scale. Furthermore, the fatigued patients showed greater evidence of damage to the forceps major, left inferior frontoccipital fasciculus, and right anterior thalamic radiation.
To predict fatigue, the researchers were able to use right inferior temporal gyrus and right anterior thalamic radiation damage as reliable predictors of patient fatigue. According to the journal article, “This study supports the use of multimodal magnetic resonance imaging and regional analysis to assess fatigue in patients with multiple sclerosis.”
The researchers are now interested in longitudinal studies to make up for some limitations of the present study. The team is interested in knowing more about fatigue in patients with the main clinical symptoms of multiple sclerosis and how it correlates to function and structure. Specifically, they would integrate functional magnetic resonance imaging to define a pathogenetic link between atrophy and fatigue severity.
A better understanding of how fatigue develops in multiple sclerosis patients could help patients whose daily lives are affected by fatigue.