Abstract
Objectives Seizure-induced reversible magnetic resonance imaging (MRI) abnormalities (SRMA) present challenges in seizure management. The study sought to investigate the frequency, evolution and prognostic value of SRMA in a consecutive series of seizure patients.
Methods A retrospective observational cohort study of seizure patients investigated with MRI of the brain was conducted. Clinical and MRI data were reviewed to determine the clinical characteristics of patients and imaging findings, including changes on serial scans, of SRMA. Outcomes (seizure freedom versus uncontrolled seizures and deaths) were assessed upon the last clinic follow-up. Mann-Whitney U test and chi-square test for independence with Bonferroni correction were used to analyze the statistical significance.
Results The study included 483 consecutive seizure patients with 7.6% developing SRMA. Patients with SRMA were found to have an older age (median 57 years, IQR 52–66, p<0.001) and longer seizure duration (median 5 minutes, IQR 2–15, p=0.002) compared with seizure patients with normal MRI. Seizure type (provoked versus unprovoked) and epileptiform EEG changes did not demonstrate a significant association. Diffusion restriction and ADC reduction observed in SRMA resolved earlier, while T2, FLAIR hyperintensities and temporal lobes changes persisted longer on follow-up scans. Median time interval from seizure to complete resolution of SRMA was 87 days (IQR 45–225). No statistical difference in outcomes was seen between patients with SRMA and normal MRIs (p=0.19).
Conclusions SRMA does not appear to be associated with subsequent seizure control or mortality. Risk factors associated with SRMA include older age and longer seizure duration.
