This study group from the USA evaluated the long term effects of IFN-β-1b on cognitive functioning in people with MS over 16 years through serial neuropsychological assessment. 16 people with relapsing-remitting MS from the 30 people included in the original study participated in a double-blind multicentre clinical trial. 4 of these 16 received low-dose IFN-β-1b, 5 patients received high-dose IFN-β-1b and 7 received placebo during the trial.
After the five year period of placebo versus IFN-β-1b, all participants had the opportunity to start IFN-β-1b for the remainder of the study and all chose to do so. All subjects underwent a brief neuropsychological assessment, MRI and completed the EDSS and Scripps Neurologic Rating Scale (SNRS) two years after entry into the trial, four years into the trial and again at 16 years. The neuropsychological assessments measured immediate and delayed memory, attention and processing speed, and depression.
Both groups exhibited relatively stable cognitive functioning over the 16 year period, but the people involved in the original placebo group showed a greater decline in verbal memory functioning as compared to the original treatment group. This may suggest that early IFN-β-1b treatment provides a neuroprotective effect against cognitive decline early in people with MS, particularly in relation to verbal memory as declines were not observed in this domain among the IFN-β-1b treatment group.
Authors: Lacy M, Hauser M
Source: Mult Scler 2013 May 7. [Epub ahead of print]
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