For patients with multiple sclerosis (MS) being treated with natalizumab, cognitive function improved from baseline to 1 year and improved significantly across all domains from baseline to 2 years.
Patients with multiple sclerosis (MS) who are treated with natalizumab show significant improvement in cognitive function over 2 years, according to a new study.
While cognitive impairment is a well-recognized characteristic of MS, affecting approximately 40% to 65% of patients, it may be insufficiently recognized and monitored. “Nonetheless, cognitive impairment has a significant adverse impact on the quality of life and functional ability of MS patients; patients with MS and cognitive impairment experience greater difficulties with activities of daily living than patients who remain cognitively intact,” wrote the researchers of the study.
Patients with cognitive impairment often experience adverse events in regard to mobility and fall risk, driving safety, and employment status. While previous studies have pointed to increased cognitive decline as the disease progresses, and others have demonstrated that natalizumab reduces disease activity, less is known about the impact of the treatment on cognitive impairment.
“In addition to a need for cognitive screening to determine the effect of MS at diagnosis and to monitor disease worsening, there is also a need for screening to evaluate the effects of treatment on cognitive function in MS,” wrote the researchers.
To this effect, the researchers studied 52 patients who were on the treatment for at least 2 years between May 2007 and August 2012. Patients had 2 or more cognitive tests while receiving 300 mg of natalizumab every 4 weeks.
Cognitive function was calculated using NeuroTrax, a computerized cognitive screening test that tests memory, executive function, visual-spatial processing, verbal function, attention, information processing speed, and motor function.
At baseline, 22 patients had a disease duration of 0-5 years, and 30 patients had a disease duration of at least 6 years. While scores for visual-spatial processing and motor function among the patients with MS were similar to the general population at baseline, scores for all other domains were lower than that of the general population.
The researchers observed that cognitive function improved from baseline to 1 year and improved significantly across all domains from baseline to 2 years. The percentage of patients experiencing a significant change in cognitive function increased from 21.6% at 1 year to 32.7% at 2 years. The most notable changes were seen in memory, visual-spatial processing, attention, and information processing speed.
Prior to treatment with natalizumab, 21.2% of patients demonstrated cognitive impairment, with individual domain impairment ranging from 19.2% for verbal function to 39.2% for information processing speed. By year 2, the rate dropped significantly to 13.5%.
According to the researchers, these findings are consistent with other studies demonstrating that natalizumab is associated with stable or improved cognitive function after 1-3 years of treatment.
“While the current study was not designed to assesses the mechanism underlying this improvement in cognitive function, previous work has suggested that these effects may be due to natalizumab’s strong anti-inflammatory effect,” they note.
Gudesblatt M, Wissemann K, Zarif M, et al. Improvement in cognitive function as measured by NeuroTax in patients with relapsing multiple sclerosis treated with natalizumab: a 2-year retrospective analysis [published online August 24, 2018]. CNS Drugs. doi: https://doi.org/10.1007/s40263-018-0553-1.