Postoperative shunt failure following hemispherectomy in pediatric patients with pre-existing hydrocephalus.

OBJECTIVE: The risk of hydrocephalus following hemispherectomy for drug resistant epilepsy (DRE) remains high. Patients with pre-existing hydrocephalus pose a postoperative challenge, as maintaining existing shunt patency is necessary but lacks a clearly defined strategy. This study examines the incidence and predictors of shunt failure in pediatric hemispherectomy patients with pre-existing ventricular shunts. METHODS: We performed a retrospective chart review at our center to identify pediatric patients diagnosed with DRE who were treated with ventricular shunt prior to their first hemispherectomy surgery. Demographic and perioperative data were obtained including shunt history, hydrocephalus etiology, epilepsy duration, surgical technique, and postoperative outcomes. Univariate analysis was performed using Fisher's exact test and Pearson correlation, with Bonferroni correction to a = 0.00625 and a = 0.01, respectively. RESULTS: Five of nineteen (26.3%) patients identified with ventriculoperitoneal shunting prior to hemispherectomy experienced postoperative shunt malfunction. All 5 of these patients underwent at least 1 shunt revision prior to hemispherectomy, with a significant association between pre- and post-hemispherectomy shunt revisions. There was no significant association between post-hemispherectomy shunt failure and valve type, intraoperative shunt alteration, postoperative external ventricular drain placement, hemispherectomy revision, lateralization of shunt relative to resection, postoperative complications, or postoperative aseptic meningitis. There was no significant correlation between number of post-hemispherectomy shunt revisions and age at shunt placement, age at hemispherectomy, epilepsy duration, or shunt duration prior to hemispherectomy. CONCLUSIONS: Earlier shunt revision surgery may portend a subsequent need for shunt revision following hemispherectomy. These findings may guide neurosurgeons in counseling patients with pre-existing ventricular shunts prior to hemispherectomy surgery.

Electroclinical Features of Infantile Epileptic Spasms Syndrome.

Epileptic spasms are a unique, age-dependent manifestation of epilepsies in infancy and early childhood, commonly occurring as part of infantile epileptic spasms syndrome. Developmental stagnation and subsequent decline may occur in children with epileptic spasms, partly due to the abundant high-amplitude interictal epileptiform and slow wave abnormalities. Early recognition and treatment of epileptic spasms, along with the reversal of the electroencephalography (EEG) findings, are critical for improving outcomes. Recognizing hypsarrhythmia and its variations is key to confirming the diagnosis. The various patterns of hypsarrhythmia are not etiology specific, but could indicate the severity of the disease. Several scoring systems have been proposed to improve the inter-rater reliability of recognizing hypsarrhythmia and to assess EEG progress in response to treatment. Ictal patterns during spasms are brief and composed of slow waves, sharp transients, fast activity, and voltage attenuation, either in isolation or more commonly as a combination of these waveforms. Ictal patterns are commonly diffuse, but may be lateralized to one hemisphere in children with structural etiology. A subset of patients with epileptic spasms has a surgically remediable etiology, with readily identifiable lesions on neuroimaging in most cases. Asymmetry in epileptic spasms, concurrent focal seizures, and asymmetric interictal and ictal EEG findings may be present, but a lack of focality in electrophysiological findings is not uncommon. Intracranial EEG features of epileptic spasms have been described, but the utility of intracranial EEG monitoring in surgical candidates with overt focal epileptogenic lesions on magnetic resonance imaging is questionable, and surgery could be performed using noninvasive data.

Pupillary constriction on stimulation of the parietal cortex-A novel finding.

Pupillary changes can be an important semiologic feature in focal epilepsy. Though the subcortical networks involving pupillomotor function have been described, cortical generators of pupillary dilation and constriction in humans are not well known. In this report, we describe a case of pupillary constriction occurring during seizures in a patient with drug resistant focal epilepsy. On stereoelectroencephalography, onset was noted within the posterior segment of the right intraparietal sulcus and direct cortical electrical stimulation of these electrode contacts reproduced pupillary constriction associated with habitual seizures. This is the first case report to describe ictal pupillary constriction during SEEG with confirmation of the cortical localization by direct cortical electrical stimulation. The posterior segment of the right intraparietal sulcus localization of pupillary constriction may aid in surgical evaluation patients with drug resistant focal epilepsy.

Epilepsy surgery for children with epileptic spasms: A systematic review and meta-analysis with focus on predictors and outcomes.

To conduct a systematic review of the literature regarding rates and predictors of favorable seizure outcome after resective surgery for epileptic spasms (ES) in pediatric patients. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed. We searched PubMed, EMBASE, and Cochrane CENTRAL for articles published on the prevalence or incidence of epileptic spasm since 1985. Abstract, full-text review, and data extraction were conducted by two independent reviewers. Meta-analysis was performed to assess overall seizure freedom rate. Subject-level analysis was performed on a subset of studies to identify prognostic indicators. A total of 21 retrospective studies (n = 531) were included. Meta-analysis of all studies demonstrated a pooled seizure freedom rate of 68.8%. Subject-level analysis on 18 studies (n = 360) demonstrated a significant association between duration of spasms and recurrence of spasms after surgery, with an estimated increased risk of 7% per additional year of spasms prior to operation. Patients who underwent resective surgery that was not a hemispherectomy (i.e., lobectomy, lesionectomy, etc.) had an increased recurrence risk of 57% compared to patients who had undergone hemispherectomy. Resective surgery results in seizure freedom for the majority of pediatric patients with epileptic spasms. Patients who undergo hemispherectomy have lower risk of recurrence than patients who undergo other types of surgical resection. Increased duration of spasms prior to surgery is associated with increased recurrence risk after surgery. PLAIN LANGUAGE SUMMARY: Children with epileptic spasms (ES) that do not respond to medications may benefit from surgical treatment. Our study reviewed existing research to understand how effective surgery is in treating ES in children and what factors predict better outcomes. Researchers followed strict guidelines to search for and analyze studies published since 1985, finding 21 studies with a total of 531 patients. They found that, on average, nearly 70% of children became seizure-free after surgery. Further individual analysis of 360 patients showed that longer duration of spasms before surgery increased the risk of spasms returning by 7% per year. Additionally, children who had less extensive surgeries, such as removal of only a specific part of the brain, had a 57% higher risk of seizure recurrence compared to those who had a hemispherectomy, which removed or disconnected half of the brain. Overall, the study concludes that surgery can often stop seizures, especially when more extensive surgery is performed and when the surgery is done sooner rather than later.

Predictive factors of hydrocephalus development in pediatric patients undergoing hemispherectomy for intractable epilepsy.

OBJECTIVE: Hemispherectomy surgery is an effective procedure for pediatric patients with intractable hemispheric epilepsy. Hydrocephalus is a well-documented complication of hemispherectomy contributing substantially to patient morbidity. Despite some clinical and operative factors demonstrating an association with hydrocephalus development, the true mechanism of disease is incompletely understood. The aim of this study was to investigate a range of clinical and surgical factors that may contribute to hydrocephalus to enhance understanding of the development of this complication and to aid the clinician in optimizing peri- and postoperative surgical management. METHODS: A retrospective chart review was conducted on all pediatric patients younger than 21 years who underwent hemispherectomy surgery at the Cleveland Clinic between 2002 and 2016. Data collected for each patient included general demographic information, neurological and surgical history, surgical technique, pathological analysis, presence and duration of perioperative CSF diversion, CSF laboratory values obtained while an external ventricular drain (EVD) was in place, length of hospital stay, postoperative aseptic meningitis, and in-hospital surgical complications (including perioperative stroke, hematoma formation, wound breakdown, and/or infection). Outcomes data included hemispherectomy revision and Engel grade at last follow-up (based on the Engel Epilepsy Surgery Outcome Scale). RESULTS: Data were collected for 204 pediatric patients who underwent hemispherectomy at the authors' institution. Twenty-eight patients (14%) developed hydrocephalus requiring CSF diversion. Of these 28 patients, 13 patients (46%) presented with hydrocephalus during the postoperative period (within 90 days), while the remaining 15 patients (54%) presented later (beyond 90 days after surgery). Multivariate analysis revealed postoperative aseptic meningitis (OR 7.0, p = 0.001), anatomical hemispherectomy surgical technique (OR 16.3 for functional/disconnective hemispherectomy and OR 7.6 for modified anatomical, p = 0.004), male sex (OR 4.2, p = 0.012), and surgical complications (OR 3.8, p = 0.031) were associated with an increased risk of hydrocephalus development, while seizure freedom (OR 0.3, p = 0.038) was associated with a decreased risk of hydrocephalus. CONCLUSIONS: Hydrocephalus remains a prominent complication following hemispherectomy, presenting both in the postoperative period and months to years after surgery. Aseptic meningitis, anatomical hemispherectomy surgical technique, male sex, and surgical complications show an association with an increased rate of hydrocephalus development while seizure freedom postsurgery is associated with a decreased risk of subsequent hydrocephalus. These findings speak to the multifactorial nature of hydrocephalus development and should be considered in the management of pediatric patients undergoing hemispherectomy for medically intractable epilepsy.