Brain activation patterns and cognitive processing speed in patients with pediatric-onset multiple sclerosis.
Nadine Akbar1,2, Brenda Banwell3, John G Sled1,4
1a Neurosciences and Mental Health Program , Research Institute, The Hospital for Sick Children , Toronto , ON , Canada.
Journal of Clinical and Experimental Neuropsychology
|December 24, 2015
Summary
Pediatric multiple sclerosis (MS) patients showed reduced frontal brain activation during a cognitive task, despite normal performance. Faster task completion in MS patients correlated with increased activation in specific brain regions, suggesting an adaptive response.
Area of Science:
- Neuroscience
- Neurology
- Medical Imaging
Background:
- Multiple Sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system.
- Pediatric-onset MS presents unique challenges in understanding disease progression and cognitive impact.
- Information processing speed is a key cognitive domain often affected in MS.
Purpose of the Study:
- To investigate brain activation patterns using functional magnetic resonance imaging (fMRI) during the Symbol Digit Modalities Test (SDMT) in pediatric-onset MS patients.
- To compare fMRI-SDMT activation between pediatric-onset MS patients and healthy controls.
- To explore the relationship between cognitive performance and brain activation within the MS group.
Main Methods:
- Utilized a functional magnetic resonance imaging (fMRI) version of the Symbol Digit Modalities Test (fMRI-SDMT).
- Recruited 20 pediatric-onset MS patients and 16 age- and sex-matched healthy controls.
- Acquired structural and fMRI data using a 3.0-tesla MRI scanner.
Main Results:
- No significant differences in response time or accuracy were found between MS patients and controls on the fMRI-SDMT.
- The MS group exhibited lower overall brain activation in the right middle frontal gyrus compared to controls.
- Within the MS group, faster performance was linked to greater activation in several regions, including the left superior occipital cortex, with a significant group interaction effect.
Conclusions:
- Pediatric-onset MS patients demonstrate attenuated frontal lobe activation during an information processing task, even without observable performance deficits.
- Increased activation in certain brain areas during faster task performance in MS patients may represent an adaptive mechanism.
- These findings suggest compensatory neural strategies may help mitigate the effects of disease-related pathology in pediatric MS.
