Responsive neurostimulation as a treatment for super-refractory focal status epilepticus: a systematic review and case series.

OBJECTIVE: Super-refractory status epilepticus (SRSE) has high rates of morbidity and mortality. Few published studies have investigated neurostimulation treatment options in the setting of SRSE. This systematic literature review and series of 10 cases investigated the safety and efficacy of implanting and activating the responsive neurostimulation (RNS) system acutely during SRSE and discusses the rationale for lead placement and selection of stimulation parameters. METHODS: Through a literature search (of databases and American Epilepsy Society abstracts that were last searched on March 1, 2023) and direct contact with the manufacturer of the RNS system, 10 total cases were identified that utilized RNS acutely during SE (9 SRSE cases and 1 case of refractory SE [RSE]). Nine centers obtained IRB approval for retrospective chart review and completed data collection forms. A tenth case had published data from a case report that were referenced in this study. Data from the collection forms and the published case report were compiled in Excel. RESULTS: All 10 cases presented with focal SE: 9 with SRSE and 1 with RSE. Etiology varied from known lesion (focal cortical dysplasia in 7 cases and recurrent meningioma in 1) to unknown (2 cases, with 1 presenting with new-onset refractory focal SE [NORSE]). Seven of 10 cases exited SRSE after RNS placement and activation, with a time frame ranging from 1 to 27 days. Two patients died of complications due to ongoing SRSE. Another patient's SE never resolved but was subclinical. One of 10 cases had a device-related significant adverse event (trace hemorrhage), which did not require intervention. There was 1 reported recurrence of SE after discharge among the cases in which SRSE resolved up to the defined endpoint. CONCLUSIONS: This case series offers preliminary evidence that RNS is a safe and potentially effective treatment option for SRSE in patients with 1-2 well-defined seizure-onset zone(s) who meet the eligibility criteria for RNS. The unique features of RNS offer multiple benefits in the SRSE setting, including real-time electrocorticography to supplement scalp EEG for monitoring SRSE progress and response to treatment, as well as numerous stimulation options. Further research is indicated to investigate the optimal stimulation settings in this unique clinical scenario.

Triggered: Discovery of Neurocysticercosis Following Self-Administered Albendazole.

A 25-year-old man with no medical history presented with a seizure one month after taking a self-administered dose of albendazole. Magnetic resonance imaging (MRI) of the brain revealed multiple ring-enhancing lesions, and the workup confirmed neurocysticercosis (NCC). Treatment with antiparasitics was delayed due to concern for worsening symptoms from the presence of cysts in the midbrain and hippocampus. The balance between treating NCC and limiting cerebral inflammation is delicate and relies on judgment from a multispecialty clinical team. In this case, corticosteroids and antiepileptics alone prevented additional seizures but failed to reduce the overall inflammation of cysts and the progression of the disease. Evidence of new cysts on MRI at week 13 from the onset of symptoms was evidence of an acute, evolving infectious process. Treatment with albendazole and praziquantel was initiated at 13 weeks from the onset of symptoms, and by 31 weeks, nearly all cysts had resolved with minimal residual inflammation.

New-Onset Seizure With Possible Limbic Encephalitis in a Patient With COVID-19 Infection: A Case Report and Review.

With the outbreak of COVID-19 (coronavirus disease 2019) as a global pandemic, various of its neurological manifestations have been reported. We report a case of a 54-year-old male with new-onset seizure who tested positive for severe acute respiratory syndrome coronavirus 2 from a nasopharyngeal swab sample. Investigative findings, which included contrast-enhancing right posterior temporal lobe T2-hyperintensity on brain magnetic resonance imaging, right-sided lateralized periodic discharges on the electroencephalogram, and elevated protein level on cerebrospinal fluid analysis, supported the diagnosis of possible encephalitis from COVID-19 infection. The findings in this case are placed in the context of the existing literature.

Relationship between high-frequency oscillations and spikes in a case of temporal lobe epilepsy.

OBJECTIVE: The aim of this case report was to study the relationship between high-frequency oscillations (HFOs), spikes, and seizures in a patient with temporal lobe epilepsy. INTRODUCTION: During intracranial electroencephalography (EEG), HFOs are thought to be a marker for the seizure onset zone (SOZ). High-frequency oscillations are classified into ripples with frequencies of 70-200 Hz and fast ripples with frequencies of 200-500 Hz. Although HFOs are thought to be a marker for the SOZ, their relationship to spikes has not been studied in detail, especially within the SOZ. METHODS: We studied the time course of ripples and spikes in a patient undergoing intracranial EEG. Medications were discontinued on day one. She suffered three seizures on day three. Her SOZ was in the left hippocampus, which displayed abundant ripples and spikes. Ripples, spikes with simultaneous ripples, and spikes without ripples were counted for this study. RESULTS: We found that ripples and spikes in the SOZ had a marked diurnal variation. Ripples, spikes with ripples, and spikes without ripples increased and decreased in concert until just before seizure onset, when ripples and spikes with ripples increased markedly. Spikes without ripples did not increase. CONCLUSIONS: These results support ripples as a marker for SOZ and show that they co-occur with spikes. Seizure onset was heralded by an increase in ripples and spikes with ripples, without an increase in spikes without ripples. We hypothesize that spikes associated with ripples may have a somewhat different pathophysiological mechanism than spikes not associated with ripples, differences that may be relevant for the timing of seizure onset.