Grant: Operating Grant

Disease of the outer layer of the brain or cortex is a previously unrecognized but important cause of both physical and mental disability in Multiple sclerosis (MS). Sparse information exists on the role of the cortex in affecting the ability to think, organize and process information. These skills are critical for social and intellectual functioning and are commonly affected in MS leading to mental disability or cognitive impairment. MRI can directly measure cortical lesions but this is very challenging because the lesions are often very small or difficult to see. This limitation is important because doctors need a reliable and commonly available method to monitor cortical disease so that they can study the effect of cortical lesions on disability. We previously show that a new MRI scan technique (or Bookend perfusion) can measure differences in the cortex between patients with and without cognitive impairment. We think the ability to show differences indirectly reflects differences in cortical disease. We found that cortical abnormality localized to expected brain regions and better predicted cognitive impairment than traditional markers including white matter disease and cortical atrophy. Importantly, we showed strong associations between abnormality and specific cognitive tests associated with information processing speed. The present proposal hopes to expand our study to less affected MS patients (or relapsing remitting MS) to determine whether similar findings are present and allow comparison between MS subtypes. This will test the relationship between disease severity, cognitive impairment and cortical abnormality. We will also assess whether similar spatial differences are seen. The study is important because our new technique is easy to use and may be performed on any MRI scanner allowing routine cortical assessment for all MS patients. The future hope is that the technique can help doctors monitor disease activity and assess the efficacy of new drugs.