Electrophysiological, Neuropsychological and Clinical Findings in Multiple Sclerosis Patients Receiving Interferon β-1b: A 1-Year Follow-Up

Abstract

We assessed serial event-related potentials (ERPs) as well as neuropsychological and clinical test findings in a group of multiple sclerosis (MS) patients (n = 14) treated with interferon β-1b (INF-β-1b) compared to normal controls (n = 14). All investigations were done within 1 week before INF-β-1b therapy was started and 12 months later. An auditory oddball paradigm was employed. No significant differences in the N100, P200, N200 or P300 latencies between patients and control group were found, but 3 out of 14 MS patients developed abnormal P300 latencies (more than 2 standard errors from the mean) after 1 year of INF-β-1b therapy. This was not reflected by the respective neurological impairment as assessed by the Expanded Disability Status Scale score. ERPs might be a useful tool in clinical studies in order to evaluate drug effects on cognition, but for a final statement, the analysis of ERPs in a larger group of patients is required.

Change in PASAT performance correlates with change in P3 ERP amplitude over a 12-month period in multiple sclerosis patients

“…Furthermore, the previous cross-sectional electrophysiological studies have reported MS patients to have decreased amplitudes and increased latencies in auditory P3b [11,[13][14][15][16][17][18] and in visual P3b [11,14,16] compared to controls. Some studies [18,19] have observed no differences between MS patients and controls.…”

“…To our knowledge, the relationship between the PASAT and P3 ERPs in MS has not been studied longitudinally, but a few studies [19,[24][25][26] have examined the change in P3b ERPs longitudinally in MS. These studies have focused on the effects of interferon treatment on cognition.…”

“…They reported that auditory P3b amplitude decreased and latencies were shortened one year later, but they did not include a control group in the study. Studies that included a control group failed to find any longitudinal differences in visual or auditory P3b after interferon treatment [19,25,26]. These studies showed improved performance in neuropsychological measures of attention and memory [19,[24][25][26] after the treatment period.…”

Cognitive impairment and neurophysiological correlates in MS

“…No significant changes are reported after 1 or 4 years of interferon h-1b therapy [27,28]; conversely significantly improved P300 latency is described after short term high dose of methylprednisolone [29].…”

Influences on cognition by immunosuppression and immunomodulation in multiple sclerosis

“…There were several small longitudinal studies over 12 months which failed to show a statistically significant positive effect of IFN beta therapy on NP functions although the mean performance of treated subjects was higher across all verbal memory tests [15,28,36].…”