Improvement in Cognitive Function as Measured by NeuroTrax in Patients with Relapsing Multiple Sclerosis Treated with Natalizumab: A 2-Year Retrospective Analysis

BACKGROUND: Cognitive impairment affects many patients with multiple sclerosis (MS). NeuroTrax, a computerized cognitive screen that can be administered during routine clinical care, provides a consistent, validated, objective cognitive profile measure with a global cognitive score (GCS) and seven individual domain scores. Natalizumab is an efficacious therapy for relapsing MS, demonstrating reductions in disability worsening and MS disease activity measured by magnetic resonance imaging. OBJECTIVE: The aim of this study was to assess cognitive function as measured by NeuroTrax in MS patients treated with natalizumab for ≥ 2 years. METHODS: This retrospective observational study included adult MS patients in the United States who received 300 mg intravenous natalizumab every 4 weeks for ≥ 2 years. NeuroTrax data were evaluated at baseline and yearly thereafter. Changes in GCS and the seven individual cognitive domain scores from baseline to after 24 infusions of natalizumab were analyzed. RESULTS: In the study population at baseline (N = 52), 22 patients (42.3%) had disease duration of 0–5 years; 12 patients (23.1%) were treatment naive. GCS score improved significantly from baseline [mean 95.5, standard deviation (SD) 12.9] to year 2 (mean 98.9, SD 13.2; change from baseline 3.4; p = 0.003). After 2 years on natalizumab, 17 patients (32.7%) demonstrated clinically significant improvement (increase from baseline > 1 SD) in GCS. Results were similar regardless of whether patients had previously received MS therapy. CONCLUSIONS: Patients treated with natalizumab demonstrated significant improvement in cognitive function, measured by NeuroTrax GCS, over 2 years of treatment.