Hemimegalencephaly: A Systematic Comparison of Functional and Anatomic Hemispherectomy for Drug-Resistant Epilepsy.

BACKGROUND AND OBJECTIVES: Hemimegalencephaly (HME) is a rare diffuse malformation of cortical development characterized by unihemispheric hypertrophy, drug-resistant epilepsy (DRE), hemiparesis, and developmental delay. Definitive treatment for HME-related DRE is hemispheric surgery through either anatomic (AH) or functional hemispherectomy (FH). This individual patient data meta-analysis assessed seizure outcomes of AH and FH for HME with pharmacoresistant epilepsy, predictors of Engel I, and efficacy of different FH approaches. METHODS: PubMed, Web of Science, and Cumulative Index to Nursing and Allied Health Literature were searched from inception to Jan 13th, 2023, for primary literature reporting seizure outcomes in >3 patients with HME receiving AH or FH. Demographics, neurophysiology findings, and Engel outcome at the last follow-up were extracted. Postsurgical seizure outcomes were compared through 2-tailed t -test and Fisher exact test. Univariate and multivariate Cox regression analyses were performed to identify independent predictors of Engel I outcome. RESULTS: Data from 145 patients were extracted from 26 studies, of which 89 underwent FH (22 vertical, 33 lateral), 47 underwent AH, and 9 received an unspecified hemispherectomy with a median last follow-up of 44.0 months (FH cohort) and 45.0 months (AH cohort). Cohorts were similar in preoperative characteristics and at the last follow-up; 77% (n = 66) of the FH cohort and 81% (n = 38) and of the AH cohort were Engel I. On multivariate analysis, only the presence of bilateral ictal electroencephalography abnormalities (hazard ratio = 11.5; P = .002) was significantly associated with faster time-to-seizure recurrence. A number-needed-to-treat analysis to prevent 1 additional case of posthemispherectomy hydrocephalus reveals that FH, compared with AH, was 3. There was no statistical significance for any differences in time-to-seizure recurrence between lateral and vertical FH approaches (hazard ratio = 2.59; P = .101). CONCLUSION: We show that hemispheric surgery is a highly effective treatment for HME-related DRE. Unilateral ictal electroencephalography changes and using the FH approach as initial surgical management may result in better outcomes due to significantly lower posthemispherectomy hydrocephalus probability. However, larger HME registries are needed to further delineate the predictors of seizure outcomes.

Isolated oculomotor nerve palsy secondary to non-aneurysmal subarachnoid hemorrhage.

We present a case series of two patients who developed unilateral cranial nerve III (CNIII) palsy following non-aneurysmal SAH (NASAH). Subarachnoid hemorrhage (SAH) can present with various signs and symptoms. Early diagnosis is paramount to determine treatment course. Thus, clinicians must be aware of the variable clinical presentations of this condition. Two patients were admitted to a single institution for SAH. Patient 1, 52-year-old male, presented with headache, left eye ptosis, and painless diplopia. A non-contrast head computed tomography (CT) demonstrated a SAH within the left sylvian fissure and blood surrounding the mesencephalon and falx. Patient 2, 70-year-old male, presented with mild headache, acute onset of blurry vision, and right eye ptosis. A non-contrast head CT demonstrated a diffuse SAH predominantly in the Sylvian and suprasellar cisterns. Patients were admitted to the neuro intensive care unit and underwent diagnostic angiograms to identify possible aneurysms. Magnetic resonance imaging and angiograms for both patients were negative. Patients were managed with best medical therapy and followed up in the outpatient setting. Unilateral CNIII palsy in the setting of NASAH was identified in both patients. Diagnostic angiograms were negative for aneurysms; therefore, SAH were determined to be spontaneous. We propose that unilateral CNIII palsy is a possible sign of NASAH.