Prognostic Value of Signal Abnormalities on Brain MRI in Post-Anoxic Super-Refractory Status Epilepticus: A Single-Center Retrospective Study

Background: Epileptiform activity, including status epilepticus (SE), occurs in up to one-third of comatose survivors of cardiac arrest and may predict poor outcome. The relationship between SE and hypoxic-ischemic brain injury (HIBI) is not established.

Methods: This is a single-center retrospective study on consecutive patients with post-anoxic super-refractory SE. HIBI was graded as non-widespread (group 1) or widespread (group 2) by qualitative analysis of DWI/ADC and T2w-FLAIR. Between-group differences in the rate of poor neurological outcome at 6 months (primary outcome), SE resolution and consciousness recovery before discharge, and mortality at 6 months (secondary outcomes) were investigated.

Results: From January 2011 to February 2023, 40 patients were included. HIBI was widespread in 45% of patients and non-widespread in 55%. The rate of poor neurological outcome at 6 months was 27% in group 1 and 83% in group 2 (OR 12.8, CI 95% [2.5-64.3], p = 0.002). The rate of consciousness recovery before discharge was 73% in group 1 versus 22% in group 2 (OR 8.8, CI 95% [1.9-40.3], p = 0.005). SE resolved in 95% of patients in group 1 versus 67% in group 2 (OR 10.5, CI 95% [1.1-97.9], p = 0.039). Mortality rate at 6 months was 27% in group 1 versus 50% in group 2 (OR 0.4, CI 95% [0.1-1.9], p = 0.303).

Conclusion: Patients with widespread HIBI had higher odds of poor outcome at 6 months, lower probability of SE resolution and of consciousness recovery before discharge compared to those with non-widespread HIBI. Mortality at 6 months did not differ significantly between the two groups.