Functional magnetic resonance imaging monitoring of the rapeutic interventions in multiple sclerosis

Introduction Several studies of patients with different neurological conditions, e.g., stroke, have unambiguously demonstrated that functional magnetic resonance imaging (fMRI) represents a powerful tool to monitor recovery of function following central nervous system (CNS) damage. More recently, the validity of this technique for assessing the longitudinal changes of brain activations after specific therapeutic interventions, i.e., rehabilitative and pharmacological, has also been assessed. Despite this, only a few studies have used fMRI for monitoring therapeutic interventions in multiple sclerosis (MS). This chapter summarizes the main issues that should be addressed when planning a longitudinal fMRI study specifically aimed at monitoring clinical recovery, either natural or modified by treatment, in patients with MS. A specific focus is devoted to fMRI changes observed with learning in healthy individuals. This provides a model for understanding the way in which brain structure and function can change with injury. Finally, the main results obtained in patients with MS are illustrated. Issues to be addressed Although studies of healthy individuals have shown that longitudinal fMRI scans have a good reproducibility, caution must be exercised when interpreting fMRI results obtained from diseased people because various factors, including abnormalities of the blood oxygenation level dependent (BOLD) effect related to the presence of inflammatory lesions, can affect data reliability across sessions.