Different cortical underpinnings for fatigue and depression in MS?

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Fatigue is a prevalent and poorly understood symptom in Multiple Sclerosis (MS).
• A significant challenge is the strong correlation observed between fatigue and depression in MS patients.
• The precise origins of fatigue in MS remain unclear.

Purpose of the Study:

• To investigate the relationship between cortical thickness and the distinct symptoms of fatigue and depression in MS patients.
• To determine if specific patterns of cortical thinning can differentiate between MS patients experiencing fatigue, depression, or both.
• To assess the contribution of cortical thickness to the variance of these neuropsychiatric symptoms.

Main Methods:

• Structural 3D T1-weighted MRI scans were acquired from 95 MS patients and 15 healthy controls.
• Cortical thickness was calculated for 84 brain areas using NeuroQLab and Automated Anatomical Labeling software.
• Regression analysis and ANOVAs were employed to analyze group differences and predict symptom presentation based on cortical thickness.

Main Results:

• Regression analysis identified the right inferior parietal cortex, middle temporal pole, and parahippocampus as significant predictors, explaining 17.3% of the variance.
• Patients with isolated fatigue showed reduced cortical thickness in the inferior parietal lobe.
• Patients with both fatigue and depression exhibited thinning in the right middle temporal pole; both groups displayed thinning in the right middle cingulate cortex.

Conclusions:

• Fatigue and depression in MS patients can be differentiated using questionnaires and cortical thickness measurements.
• Specific patterns of cortical thinning are associated with isolated fatigue or comorbid fatigue and depression.
• Cortical thickness measures account for a small proportion of the variance in these neuropsychiatric symptoms in MS.