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.

Not surgical technique, but etiology, contralateral MRI, prior surgery, and side of surgery determine seizure outcome after pediatric hemispherotomy.

OBJECTIVE: We aimed to assess determinants of seizure outcome following pediatric hemispherotomy in a contemporary cohort. METHODS: We retrospectively analyzed the seizure outcomes of 457 children who underwent hemispheric surgery in five European epilepsy centers between 2000 and 2016. We identified variables related to seizure outcome through multivariable regression modeling with missing data imputation and optimal group matching, and we further investigated the role of surgical technique by Bayes factor (BF) analysis. RESULTS: One hundred seventy seven children (39%) underwent vertical and 280 children (61%) underwent lateral hemispherotomy. Three hundred forty-four children (75%) achieved seizure freedom at a mean follow-up of 5.1 years (range 1 to 17.1). We identified acquired etiology other than stroke (odds ratio [OR] 4.4, 95% confidence interval (CI) 1.1-18.0), hemimegalencephaly (OR 2.8, 95% CI 1.1-7.3), contralateral magnetic resonance imaging (MRI) findings (OR 5.5, 95% CI 2.7-11.1), prior resective surgery (OR 5.0, 95% CI 1.8-14.0), and left hemispherotomy (OR 2.3, 95% CI 1.3-3.9) as significant determinants of seizure recurrence. We found no evidence of an impact of the hemispherotomy technique on seizure outcome (the BF for a model including the hemispherotomy technique over the null model was 1.1), with comparable overall major complication rates for different approaches. SIGNIFICANCE: Knowledge about the independent determinants of seizure outcome following pediatric hemispherotomy will improve the counseling of patients and families. In contrast to previous reports, we found no statistically relevant difference in seizure-freedom rates between the vertical and horizontal hemispherotomy techniques when accounting for different clinical features between groups.

Gait is not Affected by Hemispherotomy-Case Report from Two Children.

In children with therapy refractory epilepsy, the functional disconnection of one hemisphere (hemispherotomy) may be considered as a treatment option. The visual field defects and hand function effects associated with the procedure have been extensively studied. However, the effect of the hemispherotomy on gait pattern has thus far only been analyzed qualitatively, and there is limited quantitative data. At the Children's Hospital, we regularly perform standardized quantitative gait analysis studies and care for children with complex epilepsies. During the standard routine of care for two children with structural therapy refractory epilepsy, gait analysis was performed prior to and after hemispherotomy. Both patients had prenatal ischemic brain lesions, had developed severe epilepsy during the first 3 years of life, and were treated with the hemispherotomy at about 7 years of age. Interestingly, one patient did not show any changes in gait pattern, while for the other patient, differences could be observed by means of three-dimensional gait analysis. However, greater deviations to controls postoperatively may also be related to day-to-day variability.

An Initial Experience of Completion Hemispherotomy via Magnetic Resonance-Guided Laser Interstitial Therapy.

INTRODUCTION: In carefully selected patients with medically refractory epilepsy, disconnective hemispherotomy can result in significant seizure freedom; however, incomplete disconnection can result in ongoing seizures and poses a significant challenge. Completion hemispherotomy provides an opportunity to finish the disconnection. We describe the use of magnetic resonance-guided laser interstitial thermal ablation (MRgLITT) for completion hemispherotomy. METHODS: Patients treated with completion hemispherotomy using MRgLITT at our institution were identified. Procedural and seizure outcomes were evaluated retrospectively. RESULTS: Five patients (3 males) underwent six MRgLITT procedures (one child treated twice) for completion hemispherotomy at a median age of 6 years (range 1.8-12.9). Two children had hemimegalencephaly, two had Rasmussen encephalitis, and one had polymicrogyria. All five children had persistent seizures likely secondary to incomplete disconnection after their functional hemispherotomy. The mean time from open hemispherotomy to MRgLITT was 569.5 ± 272.4 days (median 424, range 342-1,095). One patient underwent stereoelectroencephalography before MRgLITT. The mean number of ablation targets was 2.3 ± 0.47 (median 2, range 2-3). The mean length of the procedure was 373 min ± 68.9 (median 374, range 246-475). Four of the five patients were afforded improvement in their neurocognitive functioning and speech performance after ablation, with mean daily seizure frequency at 1 year of 1.03 ± 1.98 (median 0, range 0-5). Two patients achieved Engel Class I outcomes at 1 year after ablation, one was Engel Class III, and two were Engel Class IV. The mean follow-up time was 646.8 ± 179.5 days (median 634, range 384-918). No MRgLITT-related complications occurred. Delayed retreatment (>1 year) occurred in three patients: one child underwent redo ablation and two underwent anatomic hemispherectomy. CONCLUSION: We have demonstrated the feasibility of a minimally invasive approach for completion hemispherotomy using MRgLITT. Delayed retreatment was needed in three patients; thus, further study of this technique with comparison to other surgical techniques is warranted.

Efficiency of surgery on posttraumatic epilepsy: a systematic review and meta-analysis.

Posttraumatic epilepsy (PTE) accounts for approximately 20% of structural epilepsy, and surgical intervention may be a potential treatment option for these patients. Therefore, the purpose of this meta-analysis is to evaluate the effectiveness of surgical interventions for the management of PTE. Four electronic databases (Pubmed, Embase, Scopus and Cochrane library) were searched to identify studies on surgical management of PTE. Seizures reduction rate were analyzed quantitatively in a meta-analysis. Fourteen studies involving 430 PTE patients were selected for analysis, out of which 12 reported on resective surgery (RS), 2 on vagus nerve stimulation (VNS), and 2 of the 12 RS studies reported that 14 patients underwent VNS. The seizure reduction rate for surgical interventions (both RS and VNS) was 77.1% (95% confidence interval [CI]: 69.8%-83.7%) with moderate heterogeneity (I2 = 58.59%, Phetero = 0.003). Subgroup analysis based on different follow-up times revealed that the seizure reduction rate was 79.4% (95% CI: 69.1%-88.2%) within 5 years and 71.9% (95% CI: 64.5%-78.8%) beyond 5 years. The seizure reduction rate for RS alone was 79.9% (95% CI: 70.3%-88.2%) with high heterogeneity (I2 = 69.85%, Phetero = 0.001). Subgroup analysis showed that the seizure reduction rate was 77.9% (95% CI: 66%-88.1%) within 5 years and 85.6% (95% CI: 62.4%-99.2%) beyond 5 years, with 89.9% (95% CI: 79.2%-97.5%) for temporal lobectomy and 84% (95% CI: 68.2%-95.9%) for extratemporal lobectomy. The seizure reduction rate for VNS alone was 54.5% (95% CI: 31.6%-77.4%). Surgical interventions appeared to be effective for PTE patients without severe complications, RS seemed more beneficial than VNS, while temporal lobectomy is more favorable than extratemporal resection. However, further studies with long-term follow-up data are needed to better understand the relationship between VNS and PTE.

Peri-Insular Hemispherotomy: A Systematic Review and Institutional Experience.

INTRODUCTION: Peri-insular hemispherotomy (PIH) is a hemispheric separation technique under the broader hemispherotomy group, a surgical treatment for patients with intractable epilepsy. Hemispherotomy techniques such as the PIH, vertical parasagittal hemispherotomy (VPH), and modified-lateral hemispherotomy are commonly assessed together, despite significant differences in anatomical approach and patient selection. We aim to describe patient selection, outcomes, and complications of PIH in its own right. METHODS: A systematic review of the literature, in accordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was conducted, with searches of the PubMed and Embase databases. A local series including patients receiving PIH and followed up at the Queensland Children's Hospital between 2014 and 2020 was included. RESULTS: Systematic review of the literature identified 393 patients from 13 eligible studies. Engel class 1 outcomes occurred in 82.4% of patients, while 8.6% developed post-operative hydrocephalus. Hydrocephalus was most common in the youngest patient cohorts. Developmental pathology was present in 114 (40.8%) patients, who had fewer Engel 1 outcomes compared to those with acquired pathology (69.1% vs. 83.7%, p = 0.0167). The local series included 13 patients, 11/13 (84.6%) had Engel class 1 seizure outcomes. Post-operative hydrocephalus occurred in 2 patients (15.4%), and 10/13 (76.9%) patients had worsened neurological deficit. CONCLUSION: PIH delivers Engel 1 outcomes for over 4 in 5 patients selected for this procedure, greater than described in combined hemispherectomy analyses. It is an effective technique in patients with developmental and acquired pathologies, despite general preference of VPH in this patient group. Finally, very young patients may have significant seizure and cognitive benefits from PIH; however, hydrocephalus is most common in this group warranting careful risk-benefit assessment. This review delivers a dedicated PIH outcomes analysis to inform clinical and patient decision-making.

Long-Term Patient-Reported Outcomes of Visual Field Defects and Compensatory Mechanisms in Patients After Cerebral Hemispherectomy.

BACKGROUND: In cases of intractable epilepsy resistant to drug therapy, hemispherectomy is often the only treatment option to mitigate seizures; however, the true long-term subjective visual outcomes are relatively unexplored. In this study, we sought to determine and characterize patient-reported visual function years after hemispherectomy. METHODS: This was an observational study conducted on a large cohort of children with seizure disorder treated with cerebral hemispherectomy. An online survey was sent to parents with questions to assess subjective visual function with a variety of questions from presence of visual field defects after hemispherectomy, to improvement over time, compensatory mechanisms used, and development of strabismus. RESULTS: This survey was emailed to 248 parents of previously evaluated children who agreed to be re-surveyed, 48 (20%) of which responded. The average age at hemispherectomy was approximately 5 (±4) years, and the average time after hemispherectomy was 7 (±5) years. Thirty-nine patients (81%) were seizure-free after 1 surgery and 85% (n = 41) were seizure-free after ≥1 surgeries. Thirty-four (71%) experienced a visual field defect after surgery, but 25 (52%) experienced subjective improvement over time. Thirty-eight (79%) used compensatory mechanisms, such as head tilting, with 16 (33%) patients experiencing subjective improvement over time. Twenty-seven (56%) patients experienced a decrease in visual acuity after surgery with 12 (25%) experiencing subjective improvement over time. CONCLUSION: In a large cohort examining patient-reported visual outcomes years after hemispherectomy, most patients experienced strabismus and/or visual field defects. However, more than half reported improvements and compensatory mechanisms (exotropic strabismus and ipsilateral esotropic strabismus) over time, presumably to enhance visual field function. By exploring subjective visual and cognitive function, this paper uniquely characterizes patient-reported improvements over time, and provides motivation for larger longitudinal studies using more quantitative measures of visual function and improvement after hemispherectomy.

[Lessons learnt from 101 hemispheric pediatric epilepsy surgeries part ii: pitfalls and complications]. / Uroki 101 gemisferotomii u detei s polusharnoi simptomaticheskoi epilepsiei. Chast' II: oslozhneniya i oshibki.

OBJECTIVE: To evaluate the spectrum of pitfalls and complications after hemisherotomy basing on a retrospective study of a large consecutive pediatric cohort of patients from a single institution. MATERIAL AND METHODS: One hundred and one patients (med. age - 43 months) with refractory seizures underwent hemispherotomy. Developmental pathology was the anatomical substrate of disorder in 42 patients. The infantile post-stroke scarring and gliosis was the origin of epilepsy in the majority of 43 cases with acquired etiology. The progressive pathology (RE, S-W and TS) was the etiology in the rest of children (16 cases). The lateral periinsular technique was used to isolate the sick hemisphere in 55 patients; the vertical parasagittal approach was employed in 46 cases. Median perioperative blood loss constituted 10.5 ml/kg, but was markedly larger in kids with hemimegaly (52.8 ml/kg); 57 patients needed hemotransfusion during surgery. Median length of stay in ICU was 14.7 hours, and the length of stay in the hospital until discharge - 6.5 days. Eight patients underwent second-look surgery to complete sectioning of undercut commissural fibers. FU is known in 91 patients (med. length - 1.5 years). RESULTS: Major surgical complications with serious hemorrhage and/or surgery induced life-threatening events developed in 7 patients (one of them has died on the 5th day post-surgery for the causes of brain edema and uncontrolled hyponatremia). Various early and late infectious complications were noted in 4 cases. Ten patients experienced new not anticipated but temporary neurological deficit. Nine patients needed shunting for the causes of hydrocephalus within several first months post-hemispherotomy. Early seizure onset was associated with probability of all complications in general (p=0.02), and developmental etiology - with intraoperative bleeding and hemorrhagic complications (p=0.03). CONCLUSION: Children with developmental etiology, particularly those with hemimegalencephaly, are most challengeable in terms of perioperative hemorrhage and serious complications. Patients with relapse or persisting seizures should be evaluated for the possibility of incomplete hemispheric isolation and have good chances to become SF by re-doing hemispherotomy.

Memory outcomes following hemispherectomy in children.

OBJECTIVE: A vast proportion of children with epilepsy exhibit memory impairments. Although numerous studies have examined memory performance following pediatric resective epilepsy surgery, little is known about the memory outcomes following hemispherectomy. The few studies that report on memory performance typically include restricted measures, consist of case reports, or do not report on preoperative performance. Given the current limitations, the aim of this study was to delineate pre- and postoperative memory functioning in youth who underwent a hemispherectomy. METHOD: Participants included patients who had undergone a hemispherectomy at the Hospital for Sick Children, between 1999 and 2016. Standardized neuropsychological assessments of verbal (digit span, word list recall, word pair recall, stories) and visual (faces, dot locations) memory abilities prior to and after surgery were reviewed. A Wilcoxon signed rank test and effect sizes was completed to compare patients' memory performance to population norms and to assess pre- to postoperative difference scores. RESULTS: Thirteen participants were included in the study: five patients completed preoperative assessments only and eight patients completed pre- and postoperative assessments. Preoperatively, patients performed substantially worse relative to population norms as indicated by large effect sizes (r: 0.5-0.9). Postoperatively, effect sizes were large for the majority of the memory tests, demonstrating considerable differences in patients' memory scores over time. When clinically meaningful changes were examined, stable performance was evident on 63% of the memory tasks. CONCLUSION: Overall, the results highlight that youth who are eligible for hemispherectomy demonstrate profound memory deficits prior to surgery. In addition, undergoing hemispherectomy was not necessarily associated with declined memory performance, with the majority of patients showing stable scores.

Risk factors and results of hemispherotomy reoperations in children.

OBJECTIVE: The goal of this study was to perform an analysis of a single-center experience with hemispherotomy reoperations for refractory hemispheric pediatric epilepsy due to persistence of seizures after initial surgery. The authors also identify possible anatomical and neurophysiological reasons for hemispherotomy failure, as well as risk factors and surgical options for this subgroup of patients. METHODS: A review was performed of the medical records in 18 consecutive cases in which candidates for redo hemispherotomy were treated between 2003 and 2018 at the authors' epilepsy surgery center. Fourteen patients underwent reoperation due to seizure recurrence and were studied herein, whereas in 3 the initial surgical procedure was stopped because of uncontrollable bleeding, and the remaining patient refused to undergo a reoperation in spite of seizure recurrence and went on to have a vagus nerve stimulation device placed. RESULTS: Among the 14 patients whose seizures recurred and in whom reoperations were done, the etiology of epilepsy consisted of 7 cases with malformations of cortical development (50%), 5 cases of Rasmussen encephalitis (35.8%), 1 case of porencephaly (7.1%), and 1 case of Sturge-Weber syndrome (7.1%). Eleven patients had radiological evidence of incomplete disconnection. After reoperation, 6 patients were Engel class IA, 1 was Engel II, 5 were Engel III, and 2 were Engel IV, within a mean follow-up of 48.4 months. CONCLUSIONS: Patients with malformations of cortical development have a higher risk of seizure recurrence, and these malformations comprised the main etiology in the reoperation series. Failure of an initial hemispherotomy usually occurs due to incomplete disconnection and needs to be extensively assessed. Outcomes of reoperation are most often favorable, with acceptable complication rates.

Multiple hippocampal transections: Post-operative Memory Outcomes and Seizure Control.

OBJECT: Temporal lobectomy with amygdalohippocampectomy is the standard surgical treatment for appropriate candidates with medically-intractable temporal lobe epilepsy. More recently, because of the risk of postoperative language/memory decline in a subset of patients with intact memory, a multiple hippocampal transection (MHT) approach has been proposed to preserve function. METHODS: Studies of MHT reporting both Engel and verbal memory outcome measures were included in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting of systematic reviews. Data were extracted on verbal memory function pre- and postoperatively, seizure outcome, and demographic factors. A random effects model was used to determine overall verbal memory function after MHT, and a meta-regression model was applied to identify factors associated with outcome. RESULTS: A total of 114 patients across five studies were included. Engel class I seizure outcome across all studies ranged from 64.7% to 94.7%, with 84 of the 114 patients achieving this outcome. Preoperative verbal memory score was most strongly associated with postoperative verbal memory preservation (p = 0.003). Of 59 patients with full verbal memory outcome scores, 86.8% (95% CI [confidence interval]: 77.6%-96%) had complete preservation of verbal memory relative to preoperative functional baseline. CONCLUSION: Multiple hippocampal transection is an evolving surgical technique. Although the present data are limited, the current systematic review suggests that this approach is effective at preserving verbal memory in patients with good baseline function. Although reasonable seizure outcomes have been reported with MHT, comparison to a well-established procedure such as temporal lobectomy and amydalohippocampectomy must be guided by further evidence.

A child with a stroke, drug-refractory epilepsy and congenital heart disease: can a hemispherectomy be safely performed between staged cardiac procedures?

BACKGROUND: The safety of hemispherectomy between staged cardiac procedures is unknown and not previously reported. METHOD: Retrospective review of a case with drug-resistant epilepsy due to stroke following bidirectional cavopulmonary connection (BDCPC). RESULTS: This report describes the first case of a successful pediatric peri-insular functional hemispherectomy in the setting of a BDCPC. A discussion of the complex preoperative planning from both a cardiac and neurological perspective is presented. Considerations regarding hemispherectomy and its effects on the cardiac physiology, and perioperative considerations are emphasized in clinical decision making. CONCLUSIONS: A multidisciplinary approach was critical in this child which led to a successful outcome.

Anatomical hemispherectomy revisited-outcome, blood loss, hydrocephalus, and absence of chronic hemosiderosis.

PURPOSE: To evaluate microsurgical trans-sylvian trans-ventricular anatomical hemispherectomy with regard to seizure outcome, risk of hydrocephalus, blood loss, and risk of chronic hemosiderosis in patients with intractable seizures selected for surgery using current preoperative assessment techniques. METHODS: Out of 86 patients who underwent hemispherectomy between February 2000 and April 2019, by a single surgeon, at a tertiary care referral center, 77 patients (ages 0.2-20 years; 40 females) who had an anatomical hemispherectomy were analyzed. Five of these were 'palliative' surgeries. One-stage anatomical hemispherectomy was performed in 55 children, two-stage anatomical hemispherectomy after extraoperative intracranial monitoring in 16, and six hemispherectomies were done following failed previous resection. Mean follow-up duration was 5.7 years (range 1-16.84 years). Forty-six patients had postoperative MRI scans. RESULTS: Ninety percent of children with non-palliative hemispherectomy achieved ILAE Class-1 outcome. Twenty-seven patients were no longer taking anticonvulsant medications. Surgical failures (n = 4) included one patient with previous meningoencephalitis, one with anti-GAD antibody encephalitis, one with idiopathic neonatal thalamic hemorrhage, and one with extensive tuberous sclerosis. There were no failures among patients with malformations of cortical development. Estimated average blood loss during surgery was 387 ml. Ten (21%) children developed hydrocephalus and required a shunt following one-stage hemispherectomy, whereas 10 (50%) patients developed hydrocephalus among those who had extraoperative intracranial monitoring. Only 20% of the shunts malfunctioned in the first year. Early malfunctions were related to the valve and later to fracture disconnection of the shunt. One patent had a traumatic subdural hematoma. None of the patients developed clinical signs of chronic 'superficial cerebral hemosiderosis' nor was there evidence of radiologically persistent chronic hemosiderosis in patients who had postoperative MRI imaging. CONCLUSION: Surgical results of anatomical hemispherectomy are excellent in carefully selected cases. Post-operative complications of hydrocephalus and intraoperative blood loss are comparable to those reported for hemispheric disconnective surgery (hemispherotomy). The rate of shunt malfunction was less than that reported for patients with hydrocephalus of other etiologies Absence of chronic 'superficial hemosiderosis', even on long-term follow-up, suggests that anatomical hemispherectomy should be revisited as a viable option in patients with intractable seizures and altered anatomy such as in malformations of cortical development, a group that has a reported high rate of seizure recurrence related to incomplete disconnection following hemispheric disconnective surgery.

Cognitive Development in Pediatric Epilepsy Surgery.

Epilepsy surgery is a very effective treatment option for children and adolescents with drug-resistant structural epilepsy, resulting in seizure freedom in the majority of cases. Beyond seizure freedom, the postsurgical stabilization or even improvement of cognitive development constitutes a fundamental objective. This study aims to address key features of cognitive development in the context of pediatric epilepsy surgery. Many surgical candidates present with severe developmental delay and cognitive deficits prior to surgery. Recent studies support that global cognitive development remains stable after surgery. Individual developmental trajectories are determined by the degree of presurgical developmental impairment, age at surgery, seizure freedom, antiepileptic drug tapering, and other case-specific factors. Compared with adults, children may better compensate for temporary postsurgical deficits in circumscribed cognitive functions such as memory. Particularly for left-sided temporal resections, children present a clear advantage in terms of postsurgical recovery with regard to verbal learning compared with adults. In the case of severe presurgical developmental impairment, minimal postsurgical improvements are often not measurable, although they are evident to patients' families and have a large impact on their quality of life. Multicenter studies with a standardized assessment protocol and longer follow-up intervals are urgently called for to provide deeper insights into the cognitive development after epilepsy surgery, to analyze the interaction between different predictors, and to facilitate the selection of appropriate candidates as well as the counseling of families.

Postherpetic Anti-N-methyl-D-aspartate Receptor Encephalitis after Hemispherotomy in a Patient with Intractable Startle Epilepsy.

Herpes simplex encephalitis (HSE) has been increasingly reported after neurosurgical procedures, mostly after tumor resections in patients with a prior history of HSE. Early detection and appropriate treatment are essential to prevent high mortality of the disease; however, there are diagnostic difficulties due to nonspecific prodromal symptoms. In addition, anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis has been reported after HSE as an immunological relapse. Here, we report a case of postherpetic anti-NMDAR encephalitis following right hemispherotomy for intractable startle-induced seizures, to emphasize the importance of early diagnosis and appropriate treatment. To our knowledge, this is the first reported case of anti-NMDAR encephalitis after postoperative HSE, and the third reported case of hemispherotomy as a curative treatment for startle epilepsy.

Predicting hand function after hemidisconnection.

Hemidisconnections (i.e. hemispherectomies or hemispherotomies) invariably lead to contralateral hemiparesis. Many patients with a pre-existing hemiparesis, however, experience no deterioration in motor functions, and some can still grasp with their paretic hand after hemidisconnection. The scope of our study was to predict this phenomenon. Hypothesizing that preserved contralateral grasping ability after hemidisconnection can only occur in patients controlling their paretic hands via ipsilateral corticospinal projections already in the preoperative situation, we analysed the asymmetries of the brainstem (by manual magnetic resonance imaging volumetry) and of the structural connectivity of the corticospinal tracts within the brainstem (by magnetic resonance imaging diffusion tractography), assuming that marked hypoplasia or Wallerian degeneration on the lesioned side in patients who can grasp with their paretic hands indicate ipsilateral control. One hundred and two patients who underwent hemidisconnections between 0.8 and 36 years of age were included. Before the operation, contralateral hand function was normal in 3/102 patients, 47/102 patients showed hemiparetic grasping ability and 52/102 patients could not grasp with their paretic hands. After hemidisconnection, 20/102 patients showed a preserved grasping ability, and 5/102 patients began to grasp with their paretic hands only after the operation. All these 25 patients suffered from pre- or perinatal brain lesions. Thirty of 102 patients lost their grasping ability. This group included all seven patients with a post-neonatally acquired or progressive brain lesion who could grasp before the operation, and also all three patients with a preoperatively normal hand function. The remaining 52/102 patients were unable to grasp pre- and postoperatively. On magnetic resonance imaging, the patients with preserved grasping showed significantly more asymmetric brainstem volumes than the patients who lost their grasping ability. Similarly, these patients showed striking asymmetries in the structural connectivity of the corticospinal tracts. In summary, normal preoperative hand function and a post-neonatally acquired or progressive lesion predict a loss of grasping ability after hemidisconnection. A postoperatively preserved grasping ability is possible in hemiparetic patients with pre- or perinatal lesions, and this is highly likely when the brainstem is asymmetric and especially when the structural connectivity of the corticospinal tracts within the brainstem is asymmetric.

Functional hemispherectomy is safe and effective in adult patients with epilepsy.

INTRODUCTION: Functional hemispherectomy (FH) is a well-established therapeutic option for children with epilepsy with parenchymal damage confined to one hemisphere, yet its application in adults remains rare. The intention of our study was to investigate postoperative clinical and epileptological outcome in adults who received FH for intractable epilepsy. MATERIALS AND METHODS: We retrospectively analyzed 12 adult patients (18-56years) with intractable epilepsy due to unihemispheric pathology. All patients underwent FH. Postoperative neurological and cognitive outcome as well as seizure status were evaluated with a mean follow-up period of 4.9years. RESULTS: Ten patients (83%) were seizure-free (Engel I), and two (17%) had recurrent seizures at last follow-up. Apart from one patient requiring operative revision for bone flap infection, no perioperative morbidity or mortality occurred. Postoperative functional assessment revealed deterioration of motor function in 7 patients, whereas 5 remained unchanged. Language was unchanged in 8 patients. The absence of background slowing in preoperative electroencephalogram (EEG) as well as ictal and interictal EEG patterns located ipsilateral to the side of surgery was associated with favorable seizure outcome. CONCLUSION: Favorable seizure control and acceptable functional outcome can be achieved by FH in adults with intractable epilepsy. The risk of postoperative deficits is moderate and even older patients are able to manage postoperative motor impairment. Therefore, FH should be considered in case of unihemispheric lesions also in adults.

Parental experiences before and long-term after their children's hemispherotomy - A population-based qualitative study.

Severe childhood epilepsy has an impact on the whole family. For selected children, hemispherotomy is the treatment of choice. The aim of this study was to explore parents' experiences before and after hemispherotomy as reported at a long-term follow-up and their view on received information and support. This was a population-based qualitative descriptive study, using qualitative content analysis of interviews. Seven to eighteen years after hemispherotomy, parents of twenty-one operated children were interviewed about the family life situation, expectations before surgery, and support and information before and after surgery. Before surgery, the theme 'Living in a chaotic bubble' illuminates how parents felt: the family lived in isolation, they felt both dissatisfaction and satisfaction about support and information, and they experienced that surgery was a question about life or death. After surgery, the theme 'Hovering between success and disaster' illuminates how parents hovered between happiness if the surgery was successful and sadness about e.g., complications and behavior problems. They experienced both excellent and poor support, in hospital and at rehabilitation. Regardless of all concerns, parents were satisfied that the child had received an operation. The hemispherotomies were successful and generated a better life situation. However, in order to cope, families need support and information throughout the whole process, from the onset of epilepsy and for a long time after surgery. If the child has behavior problems, an assessment should be made before surgery in order for the families to get adequate support. The specialist team needs to be involved as early as possible and follow the families for several years after surgery. Focus should be on the whole family, if needed including grandparents; family-centered care might be relevant for this patient group.

[Hemispherectomy in the treatment of pediatric symptomatic epilepsy of children]. / Gemisferektomiya v lechenii simptomaticheskoi epilepsii u detei.

INTRODUCTION AND PURPOSE: Hemispherectomy is a recognized option in the treatment of symptomatic forms of intractable focal epilepsy in patients with developmental brain malformations and some acquired lesions of one the hemispheres. The prognosis for an outcome of the technique is important in terms of the indications for surgical treatment. MATERIAL AND METHODS: We described the hemispherectomy technique and its variants and analyzed our own experience of surgery in 40 children. The most common (27 cases) brain pathology was extended unilateral cortical dysplasia with polymicro- or pachygyria and consequences of perinatal stroke. Six children had Rasmussen encephalitis; 6 patients had hemimegalencephaly; 1 child with Sturge-Weber syndrome had angiomatosis of the soft meninges. The patients' mean age was 3 years. Functional hemispherectomy (hemispherotomy) was used in most cases (37); 3 patients underwent anatomical hemispherectomy. RESULTS: At the time of discharge, seizures resolved in all patients; later, no seizure recurrence was observed in 25 out of 29 cases with known follow-up (the follow-up median was 2.5 years), which corresponded to class 1 outcomes on the ILAE scale (86%). Serious complications developed in 2 cases; 1 patient died; hydrocephalus and the need for bypass surgery occurred in other 2 children. These results are discussed along with the literature data, and the indications for hemispherectomy are provided. CONCLUSION: Hemispherectomy is a reliable and effective technique for treatment of symptomatic hemispheric forms of epilepsy in children. More than in 80% of patients with congenital or acquired pathology of one of the cerebral hemispheres, its deafferentation or resection leads to persistent elimination of seizures. Children with severe forms of intractable epilepsy should be promptly referred to dedicated centers to address the issue of advisability of surgical treatment.

Complex syntax in the isolated right hemisphere: Receptive grammatical abilities after cerebral hemispherectomy.

OBJECTIVES: In this study, we explored the syntactic competence of the right hemisphere (RH) after left cerebral hemispherectomy, on the premise that it (syntactic competence) is known to be one of the most strongly left-lateralized language functions. As basic syntactic development for individuals in this subject pool has already been extensively explored, we focused instead on the investigation of complex syntactic constructions that are normally acquired later in childhood, i.e., between 7 and 9years of age. METHODS: Grammatical competence in 10 participants who had undergone left cerebral hemispherectomy was compared to that of a group of normally developing children, with the two groups matched by the size of their vocabulary. The two tests we used for this research were created by the 1st language acquisition linguists and were designed to test sets of constructions categorized and differentiated by the order in which they are normally acquired and by the type of grammatical competence that they involve. RESULTS: We found that both groups followed the same developmental sequence of syntactic development with five (50%) postsurgical participants (all with prenatal etiologies) reaching nearly mature command of sentence grammar. Seizures negatively impacted performance on all tests. CONCLUSIONS: The isolated RH has the potential to support the complex grammatical categories that emerge relatively late in the normal acquisition of English by native speakers. Successful performance may be related to the timing of the initial insult and seizure control following hemispherectomy.