Background: Chronic, hypointense black holes (BHs) are recognized as a sign of permanent damage in patients with multiple sclerosis. Although the effects of interferon beta-1b in reducing the formation of new BHs are established, it is not clear whether the drug may reduce BH duration after these lesions are formed.
Objective: To analyze the effects of interferon beta-1b in reducing the duration of T1 BHs in patients with multiple sclerosis.
Design: Patients were clinically assessed and imaged monthly over a 36-month natural history phase and 36-month therapy phase. Numbers of contrast-enhanced lesions and newly formed BHs were counted on each scan. Each BH was counted until it was no longer seen.
Setting: Outpatient service of the Neuroimmunology Branch at the National Institutes of Health, Bethesda, Md.
Patients: Six patients with relapsing-remitting multiple sclerosis were included. One patient did not form any BHs during the therapy phase. Analyses were performed on the remaining 5 individuals.
Interventions: Interferon beta-1b at the dosage of 8 million international units every other day.
Main outcome measures: Number and duration (in months) of newly formed BHs.
Results: Rate of BH accumulation decreased with treatment (P = .01), but Kaplan-Meier models revealed that the duration of BHs did not shorten (chi2(1) = 2.47, P = .12).
Conclusions: Interferon beta-1b reduces the frequency of new BH formation but does not appear to decrease their duration in time. Analyses with larger patient cohorts are needed to confirm these preliminary findings.