The Clinical Utility of Surgical Histopathology in Predicting Seizure Outcomes in Patients with Rasmussen Encephalitis Undergoing Hemispherectomy.

OBJECTIVE: The objectives of this study were to determine the relationship between the severity of pathology and seizure outcomes in patients who underwent hemispherectomy for Rasmussen encephalitis (RE) and to investigate which clinical factors correlated with severity of pathology. METHODS: In this retrospective cohort study, we collected and reviewed pathology and clinical variables. We ascertained seizure outcomes using Engel's classification, and Pardo stages were used to grade pathology. RESULTS: We included 29 unique patients who underwent 34 hemispherectomy procedures for analysis. There was no statistically significant correlation between Pardo stage and seizure outcome (P = 1). Increasing duration of epilepsy (ß = 0.011, P = 0.02) and duration of hemiparesis (ß = 0.024, P = 0.01) were significantly associated with a more severe Pardo stage. In contrast, the presence of epilepsia partialis continua had a negative relationship with Pardo stage (ß = -0.49, P = 0.04). Twenty-six (89.75%) patients were Engel class I at the last follow-up, including all 5 patients who underwent redo hemispherectomy in our cohort. CONCLUSIONS: Consistent with the progressive nature of RE, more severe pathology was associated with a longer duration of epilepsy and longer duration of hemiparesis, while the presence of epilepsia partialis continua was associated with less severe pathology. Results from this series suggest the degree of cortical involvement with RE as assessed on surgical histopathology does not correlate with seizure outcome after hemispherectomy, which appears to be more dependent on surgical technique/complete disconnection.

Laser Interstitial Thermal Therapy for Epileptogenic Periventricular Nodular Heterotopia.

OBJECTIVE: Epilepsy with periventricular nodular heterotopia (PVNH) lacks a conclusive surgical treatment strategy as eloquent cortex and important white matter tracts frequently overlay the deep periventricular nodules. Our goal was to evaluate the safety and efficacy of laser interstitial thermal therapy (LITT) for the treatment of epilepsy in PVNH. METHODS: Data on demographic characteristics, complications, visual outcomes, Engel classification at last follow-up, antiepileptic drug use, morbidity, and mortality among patients who underwent this procedure were retrospectively reviewed. RESULTS: Between May 2015 and January 2019, 5 patients underwent 6 LITT procedures for epilepsy with PVNH. One patient had residual nodules after their first procedure and underwent a second ablation. The average follow-up time was 12 months. Three patients were Engel class Ia, 1 patient was Engel class II, and 1 patient was Engel class III at last follow-up. Two patients were able to reduce their antiepileptic drugs postoperatively. Three patients had no changes in vision, 1 patient experienced a quadrantanopsia, and 1 patient had subjective blurry vision after their procedures. No patients experienced motor deficits, dysphasia, infection, or mortality. CONCLUSIONS: LITT appears to be a safe and promising option to provide seizure relief for patients with refractory epilepsy and PVNH that otherwise may not be surgical candidates. Some appropriately determined patients with refractory epilepsy may benefit from LITT before proceeding with an invasive intracranial evaluation. A larger sample size and long-term follow-up is necessary to further elucidate safety and efficacy.