A functional magnetic resonance proof of concept pilot trial of cognitive rehabilitation in multiple sclerosis

Background: Cognitive impairment is frequent in multiple sclerosis (MS) and lacks effective treatment. Cognitive rehabilitation is widely applied in neurorehabilitation settings. Functional magnetic resonance imaging (fMRI) may help in investigating changes in brain activity and provide a tool to assess the efficacy of rehabilitation. Aim: To investigate the effect on brain activity as measured by fMRI of a cognitive rehabilitation programme in patients with MS and cognitive impairment. Method: Fifteen patients with MS and cognitive impairment and five healthy subjects were recruited. Neuropsychological assessments were performed in patients with MS at study entry and after rehabilitation to assess cognitive changes. fMRI scans were performed at week -5 (baseline), week 0 (immediately before rehabilitation) and week 5 (immediately after rehabilitation). The fMRI paradigm was the Paced Auditory Serial Addition Test (PASAT). The cognitive rehabilitation programme was composed of 15 computer-aided drill and practice sessions and five non-computer-aided cognitive stimulation group sessions (over 5weeks). Strict guidelines ensured comparability of all rehabilitation interventions. Results: Patients had increased brain fMRI activity after rehabilitation in several cerebellar areas when compared with healthy subjects. After rehabilitation, patients had significantly improved their performance on the backward version of the Digit Span Test (p = 0.007) and on a composite score of neuropsychological outcomes (p = 0.009). Conclusion: The results of the present study indicate that this cognitive rehabilitation programme increases brain activity in the cerebellum of cognitively impaired patients with MS. The role of fMRI in the assessment of neurorehabilitation schemes warrants further investigation.