Thomas Snyder

Pediatric Temporal Lobectomy for Epilepsy

Background: Temporal lobectomy in adults is an accepted form of treatment for patients with intractable complex partial seizures. There have been few long-term studies of children undergoing temporal lobectomy for epilepsy. Methods: We reviewed the pediatric cases of temporal lobectomy for intractable epilepsy performed by the Comprehensive Epilepsy Program at the University of Alberta Hospitals between 1988 and 2000. All patients had preoperative and postoperative clinical evaluations, seizure charts, drug levels, EEG, CT/MRI, long-term video EEG monitoring and neuropsychological testing. The patients were reassessed at 6 weeks, 6 months and 1 year postoperatively, then yearly. The duration of follow up was 1–10 years (mean 5 years). Results: Forty-two patients were studied (25 males and 17 females). Age at surgery ranged from 18 months to 16 years. The interictal EEG was abnormal in 38 of the 42 patients. Twenty-two patients had focal epileptic discharge and 1 had generalized epileptic discharge. Focal slowing was seen in 9 patients and diffuse slowing in 5 patients. CT scan was abnormal in 17 of 39 patients and normal in 22 of 39. MRI was abnormal in 34 of 42 patients and normal in 8 of 42. Pathology included brain tumors in 14 patients, mesial temporal sclerosis in 8, focal cortical dysplasia in 4, tuberous sclerosis in 4, dual pathology in 4, porencephalic cyst in 1 and normal pathology or gliosis in 6. Thirty-three of 42 patients (78%) were seizure-free following surgery and an additional 5 (12%) had a decrease in seizure frequency. Three patients had complications, but there were no deaths. Conclusion: Temporal lobectomy is a safe and effective treatment for children with intractable complex partial seizures. Seventy-eight percent of patients are seizure-free following the surgery and there are few complications. MRI is superior to CT scan for detection of temporal lobe pathology yet failed to detect abnormalities in some patients. The most common pathologies found were brain tumors, mesial temporal sclerosis and developmental lesions. In addition to seizure control, many patients experienced improvement in cognitive and psychosocial function following surgery.

Individual Differences Associated with Lucid Dreaming

Lucid dreaming has been said to be within the capability of all individuals (LaBerge, 1985). Based on analyses of the incidence of this dream experience among university students and among persons with an expressed interest in dreaming, a majority have reported experiencing at least one lucid dream during their lifetime, and about 20% have reported experiencing lucid dreams with relative frequency. Our goal in this chapter is to describe and to integrate what has been learned through research about individuals who experience lucid dreams. To this end we will present data derived from the study of four separable but not unrelated functional domains for which subject differences associated with lucid dreaming, or lucidity, have been found. These functional domains are (1) oculomotor/equilibratory; (2) visual/imaginal; (3) intellectual/creative, and (4) personal/interpersonal. The extent of individual differences in lucid dreaming and the methods by which these differences have been investigated will also be discussed. Because methodology is an integral part of research into individual differences, methodological considerations will first be presented.

Pediatric epilepsy surgery at the University of Alberta: 1988-2000

Epilepsy surgery is considered a treatment option for patients with intractable seizures. Relatively few studies of efficacy, safety, and long-term outcome are available for the pediatric age group. This study describes a 12-year experience with pediatric epilepsy surgery at the University of Alberta. Records of pediatric epilepsy surgery patients admitted to the Comprehensive Epilepsy Program at the University of Alberta between 1988 and 2000 were reviewed. All patients received preoperative and postoperative clinical evaluation, seizure charts, testing of drug levels, electroencephalogram, computed tomography/magnetic resonance imaging, neuropsychologic testing, and long-term video electroencephalogram monitoring. The patients were reassessed after surgery at 6 weeks, 6 months, and 1 year and then yearly. The duration of follow-up was 1 year to 12 years. Forty-two patients underwent temporal lobectomies; 35, extratemporal resection. The age at surgery ranged from 6 months to 16 years. Thirty-two (76%) of temporal lobe patients became seizure-free (Engel Class I) vs 24 (68%) for the extratemporal group (Engel Class I). One patient (2%) in the temporal group had an Engel Class II outcome and one patient (3%) in the extratemporal group had the same Engel Class II outcome. Three patients (4%) manifested postoperative complications, and there were no deaths. Patients reported improvement in cognitive abilities, behavior, and quality of life after the surgery. Epilepsy surgery in children is effective and safe. Many children are seizure-free after the operation and remain so, although the results of temporal lobectomy are better than for extratemporal resections. There are few complications, and children often have an improved quality of life.

Cortical tubers, cognition, and epilepsy in tuberous sclerosis.

Tuberous sclerosis complex is an autosomal-dominant genetic disorder characterized by hamartomatous growth in various organs. Patients who have this disorder exhibit a high rate of epilepsy and cognitive problems. We investigated number of tubers, location, seizure types, and cognitive outcome, and we analyzed the relationships among them in our tuberous sclerosis patients in the Comprehensive Epilepsy Program at the University of Alberta. We also examined the seizure outcome after tuber resection. Our study cohort included 24 patients with tuberous sclerosis complex. We obtained seizure history, electroencephalogram, and neuropsychologic parameters. Magnetic resonance imaging was used to examine tuber numbers and locations. Ten patients underwent surgical removal of tubers responsible for intractable epilepsy. A negative correlation was found between the number of tubers and intelligent quotient score. Epilepsy surgery led to freedom from seizures in this patient group. We demonstrated that the total number and location of cortical tubers play a significant role in the extent of mental retardation in patients with tuberous sclerosis complex. In addition, patients with intractable seizures and well-defined epileptic focus had excellent surgical outcome.

Pathology and Neuroimaging in Pediatric Temporal Lobectomy for Intractable Epilepsy

Objectives: Firstly, to study the pathology at surgery in children undergoing temporal lobectomy for intractable partial epilepsy. Secondly, to compare neuroimaging techniques (CT, MRI) in the preoperative detection of pathology. Lastly, to examine the surgical outcome in children. Methods: Forty-two pediatric patients undergoing temporal lobectomy for intractable epilepsy at the Comprehensive Epilepsy Program at the University of Alberta Hospital between the years 1988–1998 were studied. Patients had extensive preoperative investigations including CT and MRI. The pathology at surgery was reviewed and compared to preoperative neuroimaging. Charts were reviewed to determine surgical outcome. Results: Brain tumors were the most common pathology, found in 13/42 patients. Mesial temporal sclerosis (MTS) was found in 8 patients and dual pathology in an additional 5. Focal cortical dysplasia (FCD) was seen in 4 patients, 1 patient had a porencephalic cyst and 4 patients had tubers of tuberous sclerosis. Seven patients had no specific pathology detected. MRI was clearly more sensitive than CT in the detection of pathology. MRI was abnormal in 27/42 cases (64%), while CT scan was found to be abnormal in only 12/39 (31%). Surgical outcome was excellent, with 34/42 patients (80%) having an Engel class I outcome. One patient had significant improvement with an Engel class II outcome, 3 (7%) had little improvement (Engel class III) and 4 (10%) were unchanged (Engel class IV). Three patients (7%) had surgical complications. Conclusions: A wide variety of developmental pathology is seen following temporal lobectomy for intractable epilepsy of childhood. Brain tumors, FCD and MTS are common. MRI is superior to CT in the detection of pathology, which may be subtle in children. Surgical outcome is excellent, with most children being seizure free and few complications being seen.

Quality of life in young adults who underwent resective surgery for epilepsy in childhood.

Purpose:  This study investigated quality of life (QOL) in young adults who had undergone epilepsy surgery before the age of 16 years. The contribution to QOL of seizure status in the prior year, sex, number of antiepileptic drugs, and mood were evaluated.

Inflammasome induction in Rasmussen's encephalitis: cortical and associated white matter pathogenesis.

BackgroundRasmussen’s encephalitis (RE) is an inflammatory encephalopathy of unknown cause defined by seizures with progressive neurological disabilities. Herein, the pathogenesis of RE was investigated focusing on inflammasome activation in the brain.MethodsPatients with RE at the University of Alberta, Edmonton, AB, Canada, were identified and analyzed by neuroimaging, neuropsychological, molecular, and pathological tools. Primary human microglia, astrocytes, and neurons were examined using RT-PCR, enzyme-linked immunosorbent assay (ELISA), and western blotting.ResultsFour patients with RE were identified at the University of Alberta. Magnetic resonance imaging (MRI) disclosed increased signal intensities in cerebral white matter adjacent to cortical lesions of RE patients, accompanied by a decline in neurocognitive processing speed (P <0.05). CD3ϵ, HLA-DRA, and TNFα together with several inflammasome-associated genes (IL-1β, IL-18, NLRP1, NLRP3, and CASP1) showed increased transcript levels in RE brains compared to non-RE controls (n = 6; P <0.05). Cultured human microglia displayed expression of inflammasome-associated genes and responded to inflammasome activators by releasing IL-1β, which was inhibited by the caspase inhibitor, zVAD-fmk. Major histocompatibility complex (MHC) class II, IL-1β, caspase-1, and alanine/serine/cysteine (ASC) immunoreactivity were increased in RE brain tissues, especially in white matter myeloid cells, in conjunction with mononuclear cell infiltration and gliosis. Neuroinflammation in RE brains was present in both white matter and adjacent cortex with associated induction of inflammasome components, which was correlated with neuroimaging and neuropsychological deficits.ConclusionInflammasome activation likely contributes to the disease process underlying RE and offers a mechanistic target for future therapeutic interventions.

Self‐rated right‐left confusability and objectively measured right‐left discrimination

Normal, intelligent young adult men and women, grouped according to handedness, were compared with regard to self‐rated right‐left confusability and performance on three objective measures of right‐left discrimination, the Right‐Left Orientation Test (RLOT), Laterality Discrimination Test (LDT), and Left‐Right Reorientation Test (LRRT). Men were found to rate themselves as less susceptible to right‐left confusion and to more quickly but no less accurately make right‐left discriminations than women. Handedness did not affect right‐left confusability ratings, the accuracy of right‐left discriminations, or overall LRRT speed but did weakly affect LDT speed. Left‐handers tended to respond more quickly than right‐handers. Analyses of response latencies to different LRRT figural orientations indicated that male superiority was greater for inverted than upright figures but also applied to self‐oriented and upright figures alone. These results have implications for understanding the multidimensionality of right‐l...

Self-reported symptoms of psychological well-being in young adults who underwent resective epilepsy surgery in childhood

Purpose:  This study investigated the relationship of childhood resective surgery for lesional epilepsy and recent seizure history on self‐reported symptoms of mood and psychological distress in young adults (aged 18–30).

Patient‐reported outcome of pediatric epilepsy surgery: Social inclusion or exclusion as young adults?

Purpose:  The purpose of this study was to examine the social relationships and participation in educational, vocational, and community life in young adults who had undergone epilepsy surgery during childhood or adolescence.