6th Edition of Neurology World Conference 2026

Abstract

Abstract Background: Neuroprognostication after cardiac arrest can be challenging when clinical examination, electroencephalography (EEG), and neuroimaging do not tell the same story. Although brain MRI can provide important prognostic information after cardiac arrest, a nondiagnostic early MRI should not be interpreted as evidence against significant brain injury. Case: A 63-year-old man developed refractory nonconvulsive status epilepticus following a prolonged pulseless electrical activity cardiac arrest. Continuous EEG initially demonstrated generalized status epilepticus with bifrontal-predominant spike-and-wave discharges, generalized rhythmic activity, and brief potentially ictal rhythmic discharges. Despite treatment with multiple antiseizure medications and anesthetic infusions, electrographic abnormalities persisted and worsened with attempts to wean sedation. Subsequent EEG showed resolution of overt electrographic seizures but persistent generalized periodic discharges. Brain MRI obtained approximately 72 hours after return of spontaneous circulation showed no convincing diffusion restriction or cortical signal abnormality suggestive of acute hypoxic-ischemic injury. Instead, only generalized cerebral atrophy and chronic microvascular changes were noted. Despite the relatively unrevealing MRI, the patient remained profoundly encephalopathic with no eye opening, command following, verbal output, or motor response to noxious stimulation. Discussion: The discordance between the MRI, EEG, and neurologic examination created a significant diagnostic and prognostic challenge. The case illustrates why an early or nondiagnostic MRI should not be used in isolation to lessen concern for severe post-anoxic brain dysfunction. At the same time, refractory status epilepticus and persistent generalized periodic discharges do not, by themselves, establish irreversible injury. Sedation, metabolic abnormalities, hepatic dysfunction, and systemic critical illness may further complicate neurologic assessment. Conclusion: This case reinforces the importance of multimodal neuroprognostication after cardiac arrest. MRI findings should be interpreted in the context of their timing and limitations, while continuous EEG and serial neurologic examinations provide complementary information. When these modalities disagree, the appropriate response is continued assessment rather than premature prognostic certainty. Keywords Cardiac arrest; Nonconvulsive status epilepticus; Generalized periodic discharges; Electroencephalography; Neuroprognostication