Search

Objectives: Hemimegalencephaly (HME) is a rare congenital brain malformation presenting predominantly with drug‐resistant epilepsy. Hemispheric disconnective surgery is the mainstay of treatment; however, little is known about how postoperative outcomes compare across techniques. Thus we present the largest single‐center cohort of patients with HME who underwent epilepsy surgery and characterize outcomes. Methods: This observational study included patients with HME at University of California Los Angeles (UCLA) from 1984 to 2021. Patients were stratified by surgical intervention: anatomic hemispherectomy (AH), functional hemispherectomy (FH), or less‐than‐hemispheric resection (LTH). Seizure freedom, functional outcomes, and operative complications were compared across surgical approaches. Regression analysis identified clinical and intraoperative variables that predict seizure outcomes. Results: Of 56 patients, 43 (77%) underwent FH, 8 (14%) underwent AH, 2 (4%) underwent LTH, 1 (2%) underwent unknown hemispherectomy type, and 2 (4%) were managed non‐operatively. At median last follow‐up of 55 months (interquartile range [IQR] 20–92 months), 24 patients (49%) were seizure‐free, 17 (30%) required cerebrospinal fluid (CSF) shunting for hydrocephalus, 9 of 43 (21%) had severe developmental delay, 8 of 38 (21%) were non‐verbal, and 15 of 38 (39%) were non‐ambulatory. There was one (2%) intraoperative mortality due to exsanguination earlier in this cohort. Of 12 patients (29%) requiring revision surgery, 6 (50%) were seizure‐free postoperatively. AH, compared to FH, was not associated with statistically significant improved seizure freedom (hazard ratio [HR] =.48, p =.328), although initial AH trended toward greater odds of seizure freedom (75% vs 46%, p =.272). Younger age at seizure onset (HR =.29, p =.029), lack of epilepsia partialis continua (EPC) (HR =.30, p =.022), and no contralateral seizures on electroencephalography (EEG) (HR =.33, p =.039) independently predicted longer duration of seizure freedom. Significance: This study helps inform physicians and parents of children who are undergoing surgery for HME by demonstrating that earlier age at seizure onset, absence of EPC, and no contralateral EEG seizures were associated with longer postoperative seizure freedom. At our center, initial AH for HME may provide greater odds of seizure freedom with complications and functional outcomes comparable to those of FH. [ABSTRACT FROM AUTHOR]

Malformations of the cerebral cortex are often the causes of epilepsy. The latest changes in their classification are summarized. The description of lissencephaly and Miller–Dicker syndrome, pachygyria, polymicrogyria, hemimegaloencephaly, holoprosencephaly, schizencephaly, gray matter heterotopia is given. The features of epilepsy in these diseases are described. Magnetic resonance imaging scans for focal cortical dysplasia, polymicrogyria, and gray matter heterotopia are presented.

Klippel--Trenaunay syndrome (KTS) is characterized by localized vascular naevus, congenital or early infantile varicosities, and soft tissue or bony hypertrophy. It was been described to be associated with hemimegalencephaly and Chiari I malformation in isolation. Here we present a case of a child who presented with KTS associated with both hemimegalencephaly and Chiari I malformation. The clinical presentation of the child and the likely pathogenesis of association with Chiari I malformation in KTS are discussed. The overall management of KTS with Chiari 1 malformation is reviewed. [ABSTRACT FROM AUTHOR]

ABSTRACT A magnetic resonance diffusion fiber tracking study in neonate diagnosed with left hemisphere hemimegalencephaly is presented. Despite diffuse morphologic deformities identified in conventional imaging, all major pathways were identifiable bilaterally with minor aberrations in vicinity of morphologic lesions. [ABSTRACT FROM AUTHOR]