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At least 19 recordsLinked to original sources

Hemispherectomy and diaschisis: rapid improvement in cerebral functions after right hemispherectomy in a six year old child.

Neuroradiological, neurological, and neuropsychological studies before and after hemispherectomy for seizures of a six year old boy with left hemiplegia at birth revealed striking postoperative improvement. Seizures ceased and have not recurred. Preoperative EEC studies from seven months of age revealed increasing pathological involvement of the left as well as right hemisphere. Postoperatively, normal tracings over the left hemisphere documented marked and continuing improvement. In contrast to markedly subnormal preoperative WISC-R IQs, retest at 19 months postoperatively showed WISC-R IQs within the normal range, with similar improvement in other tests of cognitive, motor and sensory functions. The arrest and reversal of the preoperative pattern of increasing deterioration and disappearance of pathological involvement of left as well as right hemisphere functions following surgery is consistent with the disappearance of diaschisis as described by von Monakow in 1914, and has conceivably significant clinical as well as theoretical implications.

Journal Article↗

Diffusion tensor imaging of the corticospinal tract following cerebral hemispherectomy.

Following cerebral hemispherectomy, the corticospinal tract is believed to undergo reorganizational changes, which can induce enhanced function of the contralateral motor pathway and mediate partial recovery of motor function. The aim of this study was to use diffusion tensor imaging to investigate the effects of hemispherectomy on the corticospinal tract, with particular attention to the corticospinal tract contralateral to the resection. Diffusion tensor imaging would presumably detect microstructural abnormalities through quantitative measurements of the fiber tract integrity and orientation. Four patients with anatomic hemispherectomy and three patients with subtotal hemispherectomy were examined and compared with age-matched normal controls. Apparent diffusion coefficient and fractional anisotropy values were measured in regions along the corticospinal tract: internal capsule, cerebral peduncle, rostral pons, midpons, and caudal pons. None of the patients with anatomic hemispherectomy or subtotal hemispherectomy showed significant changes in either apparent diffusion coefficient or fractional anisotropy values in the corticospinal tract contralateral to the resected hemisphere, whereas increased apparent diffusion coefficient and decreased fractional anisotropy were observed in the ipsilateral rostral pons, midpons, and caudal pons of all patients with anatomic hemispherectomy, as well as in the ipsilateral cerebral peduncle of one patient with subtotal hemispherectomy. Increased apparent diffusion coefficient values were also noted in the ipsilateral internal capsule of the same patient. This study revealed no evidence of significant reinforcement of the contralateral corticospinal tract in patients with hemispherectomy, at least from diffusion tensor imaging measurements, but suggests that wallerian degeneration most likely occurs in the ipsilateral motor pathway.

Adolescent↗

Cerebral hemispherectomy in pediatric patients with epilepsy: comparison of three techniques by pathological substrate in 115 patients.

OBJECT: Cerebral hemispherectomy for intractable seizures has evolved over the past 50 years, and current operations focus less on brain resection and more on disconnection. In addition, cases involving cortical dysplasia and Rasmussen encephalitis are being identified and surgically treated in younger individuals. Few studies have been conducted to compare whether there are perioperative differences based on hemispherectomy technique and/or pathological substrate in pediatric patients with epilepsy. METHODS: In this study the authors compared, stratified by disease, anatomical (37 cases) and Rasmussen functional hemispherectomy (32 cases) with a new modified lateral hemispherotomy (46 cases). Pathological processes included cortical dysplasia (55 cases), Rasmussen encephalitis (21 cases), infarction/ischemia (27 cases), and other/miscellaneous (12 cases). The authors found differences in perioperative clinical factors based on operative technique and/or pathological substrate. In terms of technique, the lateral hemispherotomy was associated with the least intraoperative blood loss, shortest intensive care unit stay, and lowest complication rate. The anatomical hemispherectomy was associated with the longest hospital stay, delayed oral food intake, highest postsurgery fevers, and the highest incidence of shunt requirement. The functional hemispherectomy was associated with the highest reoperation rate for recurrent seizures (25%). In terms of pathology, patients with cortical dysplasia were the youngest at surgery, suffered the greatest amount of blood loss, and required the longest operative/anesthesia times compared with the other pathologically defined groups. Postoperative seizure control (range 0.5-2 years) was not statistically different according to technique or disease process and was similar to that in cases of pediatric temporal lobe epilepsy. CONCLUSIONS: The authors found differences in perioperative risks and hospital course but not postsurgery seizure control, which vary by hemispherectomy technique and/or disease process. The modified lateral hemispherotomy approach offers various advantages related to operative blood loss and reoperation compared with anatomical and functional hemispherectomies that are especially relevant in younger patients with cortical dysplasia and Rasmussen encephalitis with small and/or malformed ventricles.

Cerebral Cortex↗

Factors of morbidity in hemispherectomies: surgical technique x pathology.

OBJECTIVE: The objective of this paper is to evaluate factors of surgical morbidity from different techniques of hemispherectomy with emphasis on causative pathology. PATIENTS AND METHODS: Thirty patients underwent hemispherectomy in our institution from 1987 to 2003, two presented with Sturge-Weber Syndrome (SWS), sixteen with Rasmussen's Syndrome (RS), eight with established hemispheric lesions (EHL), and four with cortical development malformations (CDM). Six surgeons operated on three patients using anatomical hemispherectomies (AH), 11 patients using functional hemispherectomy (FH), and 16 patients employing hemispherotomy (HT). Surgical technique and causative pathology were studied independently as factors of morbidity in hemispherectomy. RESULTS: Overall mean surgical time was 11:50+/-3:20 h and increased proportionately in pathologies with larger hemispheres. Blood transfusion was particularly influenced by the approach adopted by our team of anesthesiologists, independently of technique or pathology. Pathology was the most important factor related to hydrocephalus as two out of four patients with CDM needed ventriculoperitoneal shunt whilst none with EHL or SWS. Four patients undergoing HT and one FH presented residual bridges connecting the hemispheres, three were reoperated and are seizure free. Two patients with CDM did not improve their seizures worthwhile with surgery and other two (one with RS and other with CDM) were waiting a second procedure due to incomplete inter-hemispheric disconnection. Five patients presented infection and one died after developing meningoencephalitis. CONCLUSION: Hemispherectomies are procedures where pathology and surgical technique interact narrowly. Therefore, in order to study surgical morbidity or outcome, both pathology and technique have to be analyzed independently.

Adolescent↗

Hemispherectomy for catastrophic epilepsy in infants.

PURPOSE: To report our experience with hemispherectomy in the treatment of catastrophic epilepsy in children younger than 2 years. METHODS: In a single-surgeon series, we performed a retrospective analysis of 18 patients with refractory epilepsy undergoing hemispherectomy (22 procedures). Three different surgical techniques were performed: anatomic hemispherectomy, functional hemispherectomy, and modified anatomic hemispherectomy. Pre- and postoperative evaluations included extensive video-EEG monitoring, magnetic resonance imaging, and positron emission tomography scanning. Seizure outcome was correlated with possible variables associated with persistent postoperative seizures. The Generalized Estimation Equation (GEE) and the Barnard's exact test were used as statistical methods. RESULTS: The follow-up was 12-74 months (mean, 34.8 months). Mean weight was 9.3 kg (6-12.3 kg). The population age was 3-22 months (mean, 11.7 months). Thirteen (66%) patients were seizure free, and four patients had >90% reduction of the seizure frequency and intensity. The overall complication rate was 16.7%. No deaths occurred. Twelve (54.5%) of 22 procedures resulted in incomplete disconnection, evidenced on postoperative images. Type of surgical procedure, diagnosis categories, persistence of insular cortex, and bilateral interictal epileptiform activity were not associated with persistent seizures after surgery. Incomplete disconnection was the only variable statistically associated with persistent seizures after surgery (p<0.05). CONCLUSIONS: Hemispherectomy for seizure control provides excellent and dramatic results with a satisfactory complication rate. Our results support the concept that early surgery should be indicated in highly selected patients with catastrophic epilepsy. Safety factors such as an expert team in the pediatric intensive care unit, neuroanesthesia, and a pediatric epilepsy surgeon familiar with the procedure are mandatory.

Cerebral Cortex↗

Hemimegalencephaly and intractable epilepsy: complications of hemispherectomy and their correlations with the surgical technique. A report on 15 cases.

Hemispherectomy is required in most cases of hemimegalencephaly in order to control epilepsy refractory to medical treatment. Although there is a general agreement on the effectiveness of the procedure in controlling the seizure disorder, the choice of the surgical technique is still a subject of debate. In particular, anatomical hemispherectomy is blamed to be associated with a higher incidence of surgical complications, namely hydrocephalus and hemosiderosis, than other less ablative operations such as functional hemispherectomies. A series of 15 children with hemimegalencephaly, who had undergone anatomical hemispherectomy (11 cases), functional hemispherectomy (2 cases), and hemidecortication (2 cases) at the Pediatric Neurosurgery Section, Catholic University Medical School, Rome, is reported. Twelve of these patients presented with one or more complications in their postoperative course. Temporary complications, which resolved spontaneously or following medical therapy, included fever, wound breakdown, worsening of preoperative motor deficit, unilateral third cranial nerve deficit, dystonia, and anemia. In 8 patients, postoperative complications led to a second surgical procedure. A CSF shunt was necessary in 5 children, to control a secondary hydrocephalus. Two subjects underwent a toilette of the residual cavity because of persisting chemical abnormalities in CSF parameters. In a child a cranioplasty procedure was necessary as a consequence of an infection of the hemicranial bone flap. There was no apparent correlation between the rate and the type of complications with a specific surgical procedure. On the other hand, the age factor appeared to play an important role in the occurrence of secondary hydrocephalus, as all 5 children with this complication were less than 9 months old at the time of the hemispherectomy. Surgical mortality was nil in this series.

Brain↗

Outcomes of 32 hemispherectomies for Sturge-Weber syndrome worldwide.

BACKGROUND: Epilepsy affects 80% of patients with Sturge-Weber syndrome; the majority of seizures begin before the age of 1. When seizures are intractable to medications and unihemispheric, hemispherectomy is often advised. OBJECTIVE: To examine the natural history of patients who underwent hemispherectomy and identify the outcomes in terms of seizure reduction, cognition, and motor deficits. METHODS: A questionnaire was mailed to the parents of patients identified by the Sturge-Weber Foundation as having had a hemispherectomy between 1979 and 2001. Forty-six percent (32/70) of the parents responded. RESULTS: The mean age at onset of seizures was 4 months, and the median age at surgery was 1.2 years. Children had failed to respond to 3.7 anticonvulsants prior to surgery and averaged 387 seizures/month. Forty-seven percent had complications (e.g., hemorrhage and hypertension) in the perioperative period; however, 81% are currently seizure-free, with 53% off anticonvulsants. Hemispherectomy type (anatomic versus functional versus hemidecortication) did not influence outcome. Age at onset of seizures did not predict seizure freedom; however, an older age at hemispherectomy was positively correlated. Postoperative hemiparesis was not more severe than before surgery. Cognitive outcome was not related to the age at operation, side of operation, or seizure freedom. CONCLUSIONS: Children undergoing hemispherectomy presented at a young age and had frequent seizures for approximately 1 year but are now mostly seizure-free. Age at surgery did not have an adverse effect on either seizure or cognitive outcomes.

Adolescent↗

Hemispherectomy procedures in children: haematological issues.

OBJECTS: In literature, excessive perioperative haemorrhage and related haemodynamic instability have been described as major risk factors in hemispherectomy. In this report we analyse the impact of neurosurgical operation on both the haematological and coagulative patterns of these children, especially focusing on younger patients. METHODS: From 1993 to 2003, 18 consecutive children suffering from intractable epilepsia and treated by hemispherectomy were admitted to the Pediatric Intensive Care Unit (PICU) of Catholic University Medical School, Policlinico Gemelli, Rome. Eight children had an entire hemisphere removed (anatomical hemispherectomy), whereas the remaining 10 underwent disconnective procedures (functional hemispherectomy) or cerebral cortex ablations (e.g. hemicorticectomy). Eleven out of these 18 children underwent hemispherectomy because of hemimegalencephaly (HME): their mean age was 14.5 months (range 3-56 months); non-HME patients underwent surgery for epileptogenic lesions involving the cerebral hemisphere to a great extent or diffusely. Data have been compared with an historical cohort of 13 children operated on before 1992 at the same institution comparable for age, aetiology of epilepsy and the modalities of surgical operation. CONCLUSIONS: Blood losses and haemotransfusions showed a profound influence on the haematologic/coagulative status of the children operated upon. A strict correlation was demonstrated between estimated red cell volume (ERCV) loss and haemostatic impairment in this series. Recent surgical techniques appear to reduce blood losses and related haemocoagulative risks even in younger patients.

Blood Coagulation Disorders↗

Transsylvian functional hemispherectomy.

OBJECTIVE: To describe the technique of transsylvian-transventricular functional hemispherectomy developed at our institution. METHODS: We review appropriate patient selection and evaluation, timing of surgery, selection of surgical approach, preoperative preparation, details of operative procedure, and postoperative management. CONCLUSIONS: The transsylvian "keyhole" functional hemispherectomy technique involves a smaller craniotomy than other functional hemispherectomy techniques and consists of transsylvian exposure, resection of mesial temporal structures, transventricular frontobasal disconnection, callosotomy, and occipitoparietal disconnection. The key advantages of this approach compared to the Rasmussen's "classic" functional hemispherectomy are smaller exposure, shorter operative time, and lower blood loss. The efficacy of functional hemispherectomy procedures in achieving seizure freedom appears to be at least as good compared to resective procedures. The long-term complication rate will require longer follow-up times.

Cerebral Cortex↗

Five or more acute postoperative seizures predict hospital course and long-term seizure control after hemispherectomy.

PURPOSE: Acute postoperative seizures (APOSs) are those that occur in the first 7 to 10 days after surgery, and previous studies in temporal lobe epilepsy patients support the notion that APOSs may foretell failure of long-term seizure control. It is unknown whether APOSs also predict seizure outcome or hospital course after hemispherectomy. METHODS: Hemispherectomy patients (n = 114) were studied retrospectively and subdivided into the following groups: No APOSs, 1 to 5 APOSs, or >5 APOSs. Intensive care unit (ICU) nursing staff or family members reported and described the APOS events. APOS categories were compared with pre- and postsurgery clinical variables abstracted from the medical record. RESULTS: APOSs occurred in 22.6% of hemispherectomy patients. Compared with the 0 and 1 to 5 APOS groups, patients with >5 APOS showed (a) longer seizure durations before surgery, (b) longer hospitalizations, (c) later oral food intake, (d) more frequent lumbar punctures, (e) worse seizure control at 0.5 and 1 year after surgery, (f) more antiepileptic drug (AED) use at 2 and 5 years after surgery, and (g) higher reoperation rate. No similar differences were found between the 0 and 1 to 5 APOS groups. The day of the APOS, whether the APOS was typical of preoperative seizures, and postsurgery scalp EEG did not predict long-term seizure control. APOS patients in the 1 to 5 and >5 groups had lower pre- and postsurgery Vineland developmental quotients compared with those without an APOS. CONCLUSIONS: Hemispherectomy patients with >5 APOSs had a more prolonged and complicated hospital course and worse postsurgery seizure control, more AED use, and higher reoperation rate than did patients with 0 or 1 to 5 APOSs. Thus the number of APOSs was a predictor of postsurgery seizure control and can be used to counsel patients and families about prognosis after hemispherectomy.

Acute Disease↗

Compensatory motor function of the somatosensory cortex for dysfunction of the motor cortex following cerebellar hemispherectomy in the monkey.

Electrical activities of the motor and somatosensory cortices preceding visually-initiated hand movements were recorded with electrodes chronically implanted on the surface and at 2.5-3.0 mm depth in the cortex of monkeys, and changes in field potentials in these cortices after cerebellar hemispherectomy were observed for many weeks. As previously reported, a unilateral cerebellar hemispherectomy including the lateral and interpositus nuclei eliminates the cerebellar-mediated superficial thalamo-cortical (T-C) responses recorded in the forelimb motor cortex contralateral to the hemispherectomy. These T-C responses normally precede the hand movement, and the operation results in the delay of movement initiation. The electrodes in the forelimb area of the contralateral primary somatosensory cortex showed an enhancement of superficial T-C responses of the somatosensory cortex for 30-40 days after the operation. The enhanced potentials preceded the delayed movement as do the cerebellar-mediated superficial T-C responses of the motor cortex in normal situations. Local cooling of the somatosensory cortex following the cerebellar hemispherectomy disturbed the reaction time movement for a few weeks after the operation. This effect was rarely encountered in normal monkeys. The present study suggests the compensatory motor function of the somatosensory cortex for the dysfunction of the motor cortex in early weeks after cerebellar hemispherectomy.

Adaptation, Physiological↗

Hemispherectomy for intractable seizures in children: a report of 58 cases.

Fifty-eight children who underwent anatomical, functional, or modified anatomical hemispherectomy for intractable seizures from 1986 to 1995 were evaluated for seizure control, motor function, and complications. Age at surgery ranged from 0.3 to 17.3 years (median 2.8 years). Twenty-seven anatomical, 27 functional, and 4 modified anatomical hemispherectomies were performed. Seizure control and motor function in the 50 patients with more than 1 year follow-up revealed a 90% or better reduction in seizure frequency in 44/50 (88%) overall: 19/22 (86%) anatomical, 23/26 (89%) functional, and 2/2 modified anatomical. Motor function of the preoperatively hemiparetic extremities was improved or unchanged postoperatively in 38/50 (76%) of the patients. Complications included one intraoperative death, one late death from shunt obstruction managed elsewhere, late postoperative seizure breakthrough requiring reoperation and further disconnection in 5/27 functional hemispherectomy patients, mild cerebrospinal fluid infections in 3/27 anatomical hemispherectomy patients, and hydrocephalus requiring shunting in 3/27 functional hemispherectomy patients. A review of the literature and comparison of techniques is presented.

Adolescent↗

Hemispherical deafferentation: an alternative to functional hemispherectomy.

An alternative technique for so-called functional hemispherectomy has been developed to be used for the classical indications of hemispherectomy or the various modifications of functional hemispherectomy. The technique entails a smaller trepanation, less operation time, and less blood loss, and it leaves more brain tissue in place as compared with other functional hemispherectomy techniques. It starts with either hippocampectomy alone or with hippocampectomy and anterior temporal lobectomy. After this, deafferentation of the white matter of the temporal, occipital, parietal, and frontal lobe, using either a transcortical transventricular approach along the outline of the lateral ventricle or a sylvian key hole approach, is performed. The technique includes a transventricular callosotomy, and it leaves in place only a small portion of the suprainsular cortex and the insular cortex. However, as one modification, removal of the insular cortex can easily be performed, if necessary, and, as a second modification, the entire transventricular deafferentation can be performed through a sylvian key hole. In this report, the technique is described and the surgical experience for the first 13 patients is outlined. The immediate seizure relief with an average follow-up of 12 months was similar to that for patients with functional hemispherectomy, but the follow-up period for these 13 patients is not long enough to allow definite conclusions concerning long-term control of seizures and long-term complications.

Adolescent↗

The role of hemispherectomy in the treatment of holohemispheric hemimegaloencephaly.

The role of hemispherectomy in treating holohemispheric hemimegaloencephaly, a unilateral brain malformation, is still not well defined. The authors describe the cases of five infants presenting with intractable seizures, progressive neurological deficits, and severe developmental delay. Electroencephalography (EEG) showed generalized polyspikes from the megaloencephalic hemisphere and progressive slowing on the opposite side in all children; contralateral seizure spikes occurred in three children. Three of the five children underwent hemispherectomy for intractable seizures before 2 years of age, after which the seizures subsided completely in two children and improved remarkably in the third. Preoperative Wada testing proved useful in evaluating pharmacologically the effect of hemispherectomy on contralateral polyspikes. Postoperative EEG revealed the absence of polyspikes in the operated hemisphere and decreased slowing on the contralateral side. Psychomotor development in the surgically treated infants exceeded that of the children not undergoing hemispherectomy. Of the two children treated medically, one died at 4 years of age in status epilepticus and the other (now 5 years old) has frequent seizures and severe developmental delay. Based on these results, hemispherectomy appears to be a useful procedure for controlling seizures and improving psychomotor development in children with hemimegaloencephaly involving the entire hemisphere. Surgery in infancy can prevent or minimize seizure foci and encephalopathic changes that may develop in the contralateral hemisphere. Staging the procedure and exercising meticulous hemostasis make surgery relatively safe in infants who otherwise may have significant blood loss associated with increased blood flow to the megaloencephalic hemisphere.

Anticonvulsants↗

Anatomical hemispherectomy for intractable seizures: excellent seizure control, low morbidity and no superficial cerebral haemosiderosis.

OBJECTIVE: This current study was performed to evaluate whether superficial cerebral haemosiderosis (SCH) is still a complication of modern day anatomical hemispherectomy. METHODS: We report a 13-year institutional experience with anatomical hemispherectomy for intractable epilepsy. Seizure control at a mean follow-up interval of 7 years was 83%. Though one patient died post-operatively from a non-neurosurgical complication, mortality was otherwise zero and morbidity minimal. The much-described complication of SCH following anatomical hemispherectomy was non-existent. We explain the history of SCH as a complication of anatomical hemispherectomy, and the measures that are presently taken to prevent it. CONCLUSIONS: We suggest that the importance of SCH in modern epilepsy surgery is probably over-emphasised.

Adolescent↗

Hemispherectomy: a schematic review of the current techniques.

Anatomical hemispherectomy has been used for the treatment of seizures since 1938. However, it was almost abandoned in the 1960s after reports of postoperative fatalities caused by hydrocephalus, hemosiderosis, and trivial head traumas. Despite serious complications, the remarkable improvement of patients encouraged authors to carry out modifications on anatomical hemispherectomy in order to lessen its morbidity while preserving its efficacy. The effort to improve the technique generated several original procedures. This paper reviews current techniques of hemispherectomy and proposes a classification scheme based on their surgical characteristics. Techniques of hemispherectomy were sorted into two major groups: (1) those that remove completely the cortex from the hemisphere and (2) those that associate partial cortical removal and disconnection. Group 1 was subdivided into two subgroups based on the integrity of the ventricular cavity and group 2 was subdivided into three subgroups depending on the amount and location of the corticectomy. Grouping similar techniques may allow a better understanding of the distinctive features of each one and creates the possibility of comparing data from different authors.

Cause of Death↗

Postoperative fever after hemispherectomy: the role of non-infectious factors.

Postoperative fever is a usual source of concern among caregivers and patients' family given that it may reflect a wide range of complications. The objective of this paper was to outline the expected postoperative temperature variation after hemispherectomies, and to establish factors that affect this curve. From 1987 to 2003, 30 patients were hemispherectomized in our institution. Among them, 24 patients without clinical diagnosis of infection were selected for this study. Postoperative axillary temperature from each patient was recorded over 10 days. Data was initially analyzed for all 24 patients and, later, for subgroups by (1) surgical technique (functional hemispherectomy, anatomical hemispherectomy, and hemispherotomy) and (2) hemispheric volume of the causative pathology (groups with large, moderately atrophic, and severely atrophic hemispheres). There was a trend of temperature elevation (p=0.06) over the first 4 days in all patients where 14 subjects recorded values over 38.5 degrees C, and 3 over 39.0 degrees C. Temperature curves from subgroups undergoing different techniques presented no statistical differences. However, the group including causative pathologies with larger hemispheres had a higher temperature curve when compared to patients with severely atrophic hemispheres (p<0.05). Our findings support the view that fever is an predictable event after hemispherectomies and causative pathologies with larger hemispheres present higher postoperative temperatures.

Antibiotic Prophylaxis↗

Disconnective hemispherectomy for hemispheric dysplasia.

Twelve patients suffering from intractable epilepsy and presenting with radiological evidence of diffuse hemispheric involvement of a dysplastic process, were treated by disconnective hemispherectomy, either functional hemispherectomy or peri-insular hemispherotomy. The median age at surgery was 4.5 years old and the interval between seizure onset and surgery, 3 years. All patients underwent a presurgical evaluation that led to the suggestion of disconnective hemispherectomy. Over 70% of patients have remained in Engel's seizure outcome class I since surgery and another 18% have had a satisfactory seizure outcome. There was one unexplained death and one case of early hydrocephalus. Hemispherectomy offers the possibility to improve seizure control in the majority of patients undergoing surgery for extensive dysplastic pathology of the hemisphere. Disconnective techniques reduce the rate of complications in this specific pathology.

Adolescent↗