Functional MRI Activation of Inhibitory Control in Adolescents and Young Adults with Multiple Sclerosis

Inhibitory control, defined as the ability to withhold a response, is typically preserved in patients with multiple sclerosis (MS), despite impairment in other executive functions. This study examined the concept of functional reorganization concerning inhibitory control using a simple Go/No-go (GNG) functional MRI paradigm in pediatric-onset MS. The control group demonstrated greater functional activation as compared with the patient group in several regions: cerebellum, brainstem, lateral occipital cortex, parahippocampal gyrus, precuneus, superior parietal lobe, precentral gyrus and superior frontal gyrus. Cognitively intact pediatric-onset MS patients show less brain activation than controls when inhibiting a simple motor response despite no differences in behavioural performance. Functional differences were observed in the posterior and anterior regions of the response inhibition network in the MS group suggesting a less developed attention network. Further characterization of cerebellar-neocortical connectivity is required to understand the potential for functional plasticity in response to injury in pediatric-onset MS.