Mortality in pediatric epilepsy

Psychometric validation of the Pediatric Symptom Checklist-17 in a pediatric population with epilepsy: A methods study

OBJECTIVE

The purpose of this study was to address critical gaps in behavioral health care of youth with epilepsy by examining the utility of a brief, well-validated screening instrument, the PSC-17, in a pediatric population with epilepsy.

METHOD

One hundred eighty-seven caregivers of youth with epilepsy ages 2-17years completed the PSC-17 for their child/adolescent during a routine epilepsy visit. Demographic and seizure information was abstracted from electronic medical record review.

RESULTS

Confirmatory factor analyses for the PSC-17 revealed an acceptable fit with the 3-factor model, χ(2) (116 [N=187]=204.54, p<0.001, CFI=0.90, TLI=0.88, RMSEA=0.064, SRMSR=0.078). Scale level reliabilities were excellent (0.72-0.85). Interscale correlations were moderate (0.48-0.69). Approximately 1/5th of the sample met clinical cut-offs for the total score of behavioral health concerns. However, an additional 20% of the sample had at least one elevated subscale score despite the total score being in the normative/nonclinical range.

SIGNIFICANCE

The PSC-17 is a brief, free behavioral health screening tool with adequate to strong validity, reliability, and clinical utility for pediatric populations with epilepsy. Clinicians should consider using the 3 PSC-17 subscale scores instead of the total score to guide referrals for further evaluation as the subscales may provide a more accurate picture of functioning in particular domains.

Developing the Pediatric Refractory Epilepsy Questionnaire: a pilot study

PURPOSE

Up to 14% of children with epilepsy continue to experience seizures despite having appropriate medical therapy and develop medically refractory epilepsy (MRE). Assessing clinical outcomes and therapeutic efficacy in children with MRE undergoing palliative epilepsy surgery has been challenging because of the lack of a quantitative instrument capable of estimating the clinical status of these patients. The ideal instrument would at once consider seizure control, neurodevelopment, caregiver burden, and quality of life. The purpose of this study was to develop and pilot the Pediatric Refractory Epilepsy Questionnaire (PREQ), a quantitative instrument to assess the severity and individual burden of epilepsy in children with MRE undergoing palliative epilepsy treatments.

METHODS

The caregivers of 25 patients with MRE completed the PREQ and the Quality of Life in Childhood Epilepsy (QOLCE) measure and participated in a semistructured interview. Medical records of the patients were reviewed, an Early Childhood Epilepsy Severity Scale (E-CHESS) score was calculated, and a Global Assessment of Severity of Epilepsy (GASE) score was obtained for each patient.

KEY FINDINGS

The initial PREQ was modified based on the analysis of responses, association with previously validated scales, comments from caregivers, and expertise of the PREQ panelists. Pediatric Refractory Epilepsy Questionnaire subscale scores were calculated based on clinical paradigm and compared with independent measures of seizure severity and quality of life. Significant correlations were observed between the seizure severity subscale and the GASE score (r=0.55) and between the mood subscale and the well-being score (r=0.61) on the QOLCE. Significant correlations were also observed between the caregiver rating of seizure severity and the GASE score (r=0.53), the social activity score (r=0.57), and the behavior score (r=0.43) on the QOLCE. Correlations between the caregiver rating of quality of life and the quality of life score (r=0.58) and the number of AEDs used (r=0.45) were also significant.

SIGNIFICANCE

This pilot study is an initial, critical step in the development of the PREQ. The significant correlations between the PREQ subscales and the external epilepsy severity and quality of life measures lend preliminary support to our hypothesis that the PREQ is assessing the severity of epilepsy along with other important domains, such as mood, neurodevelopment, and quality of life. A larger prospective study of this modified PREQ is currently underway to further develop the PREQ.

Outcomes After Anterior or Complete Corpus Callosotomy in Children

BACKGROUND:

Corpus callosotomy (CC) is a valuable palliative surgical option for children with medically refractory epilepsy due to generalized or multifocal cortical seizure onset.

OBJECTIVE:

To investigate the extent of CC resulting in optimal seizure control in a pediatric patient population and to evaluate the modification of seizure profile after various CC approaches.

METHODS:

The records of 58 children (3–22 years of age at the time of surgery) with medically refractory epilepsy who underwent CC between 1995 and 2011 were retrospectively reviewed.

RESULTS:

Anterior two thirds callosotomy resulted in resolution of absence (P = .03) and astatic (P = .03) seizures, whereas anterior two thirds callosotomy followed by second-stage completion resulted in resolution of generalized tonic-clonic (GTC) (P = .03), astatic (P = .005), and myoclonic (P = .03) seizures in addition to a trend toward resolution of absence seizures (P = .08). Single-stage upfront complete callosotomy resulted in resolution of absence (P = .002), astatic (P &lt; .0001), myoclonic (P = .007), and complex partial (P = .008) seizures in addition to a trend toward resolution of GTC (P = .06). In comparing a composite of subjects who underwent anterior two thirds callosotomy alone or 2-stage complete callosotomy before the second stage to complete the callosotomy with subjects who underwent upfront complete CC, a more favorable outcome was found in those with the upfront complete CC (P = .02).

CONCLUSION:

Single-stage upfront complete callosotomy is effective in relieving a broader spectrum of seizure types than anterior two thirds callosotomy or 2-stage complete callosotomy in children. The advantages of single-stage complete callosotomy must be weighed against the potentially higher risk of neurological and operative complications.

Characterization of the supplementary motor area syndrome and seizure outcome after medial frontal lobe resections in pediatric epilepsy surgery

BACKGROUND

In adults, resection of the medial frontal lobe has been shown to result in supplementary motor area (SMA) syndrome, a disorder characterized by transient motor impairment. Studies examining the development of SMA syndrome in children, however, are wanting.

OBJECTIVE

To characterize the development of SMA syndrome and to analyze seizure outcomes after surgery in the medial frontal lobe for medically intractable epilepsy.

METHODS

Thirty-nine patients with medically intractable epilepsy who underwent surgery in the medial frontal lobe were reviewed retrospectively. The progression of neurological impairment and seizure outcome after surgery was recorded, and the extent of cortex resected was analyzed.

RESULTS

After resection in the region of the SMA, 23 patients (59%) developed postoperative neurological impairment; 17 (74%) were identified as SMA syndrome. No neurological impairment was found after surgery in 16 patients (41%). Six patients (15%) experienced permanent neurological impairment. The majority of patients (82%) who developed SMA syndrome had resolution of their symptoms by 1 month postoperatively. Preoperative magnetic resonance imaging finding of lesional cases was associated with a significantly decreased likelihood of developing SMA syndrome (P = .02). Seizure outcome was favorable after surgery in most patients.

CONCLUSION

Surgery for medically intractable epilepsy in the region of the medial frontal cortex is effective and associated with reversible neurological impairment in children. All patients had resolution of their SMA syndrome by 6 months postoperatively.

Unexplained drownings and the cardiac channelopathies: a molecular autopsy series

OBJECTIVE

To determine the prevalence and spectrum of mutations associated with long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) in a seemingly unexplained drowning cohort.

PATIENTS AND METHODS

From September 1, 1998, through October 31, 2010, 35 unexplained drowning victims (23 male and 12 female; mean ± SD age, 17±12 years [range, 4-69 years]) were referred for a cardiac channel molecular autopsy. Of these, 28 (20 male and 8 female) drowned while swimming, and 7 (3 male and 4 female) were bathtub submersions. Polymerase chain reaction, denaturing high-performance liquid chromatography, and DNA sequencing were used for a comprehensive mutational analysis of the 3 major LQTS-susceptibility genes (KCNQ1, KCNH2, and SCN5A), and a targeted analysis of the CPVT1-associated, RYR2-encoded cardiac ryanodine receptor was conducted.

RESULTS

Of the 28 victims of swimming-related drowning, 8 (28.6%) were mutation positive, including 2 with KCNQ1 mutations (L273F, AAPdel71-73 plus V524G) and 6 with RYR2 mutations (R414C, I419F, R1013Q, V2321A, R2401H, and V2475F). None of the bathtub victims were mutation positive. Of the 28 victims who drowned while swimming, women were more likely to be mutation positive than men (5/8 [62.5%] vs 3/20 [15%]; P=.02). Although none of the mutation-positive, swimming-related drowning victims had a premortem diagnosis of LQTS or CPVT, a family history of cardiac arrest, family history of prior drowning, or QT prolongation was present in 50%.

CONCLUSION

Nearly 30% of the victims of swimming-related drowning hosted a cardiac channel mutation. Genetic testing should be considered in the postmortem evaluation of an unexplained drowning, especially if a positive personal or family history is elicited.

Childhood drowning in Manitoba: A 10-year review of provincial Paediatric Death Review Committee data

BACKGROUND

Drowning is the second leading cause of unintentional injury death for Canadian children up to 19 years of age. Specific regional drowning prevention strategies require a detailed understanding of patterns of injury, including risk factors. Paediatric death review committees have the opportunity to identify these risk factors, and to identify and advocate prevention strategies.

OBJECTIVES

The purpose of the present study was to analyze Manitoba Paediatric Death Review Committee (PDRC) drowning data to identify drowning risk factors and potential prevention strategies.

METHODS

A 10-year (1988-1997) review of the College of Physicians and Surgeons of Manitoba PDRC database was performed. Drowning deaths were summarized in terms of demographic variables and lack of supervision at the time of the drowning events.

RESULTS

Seventy-three drowning deaths were reviewed by the PDRC during the study period. These children ranged from 29 days to 14 years of age. They included 50 boys and 30 First Nations children. The highest mortality rates were found in First Nations children (12.4/100,000 First Nations children compared with 1.9/100,000 non-First Nations children), boys (3.9/100,000 boys compared with 1.9/100,000 girls) and toddlers aged one to four years (5.9/100,000 children).

CONCLUSIONS

Priority populations for drowning prevention in Manitoba include First Nations children, boys and toddlers. Death review committees can contribute to childhood injury prevention by reviewing injury deaths, analyzing and reporting injury mortality data, and identifying and advocating prevention strategies.

Sudden unexpected death in epilepsy (SUDEP): a pilot study on truth telling among Italian epileptologists

Sudden unexpected death in epilepsy (SUDEP) is a syndrome where a person with epilepsy dies suddenly and no other cause of death is found. The question of informing patients and their families about SUDEP remains a problematic issue. The aim of this study is to explore whether Italian physicians interested in epilepsy believe that they should discuss SUDEP with patients and/or their families. A total of 315 questionnaire were distributed, of which 195 (61.9%) were returned. Seventeen respondents (8.76%) discussed SUDEP with all of their patients, 38 (19.59%) with the majority of patients, 120 (61.85%) with very few of their patients and 15 (7.73%) with none of their patients. No statistical differences among groups were found for gender, professional age (≤ 10 years; ≥ 11 years ≤ 20 years; ≥ 21 years ≤ 30 years; ≥ 31 years) and medical specialty (neurologists vs. others). Open questions offered insights into the physicians' problem of managing the negative emotions of patients/family and why the physicians decided to give information.

Comorbidity, health screening, and quality of life among persons with a history of epilepsy

Previous population surveys outside the United States have found an increased prevalence of comorbid conditions in persons with epilepsy. However, the effect of comorbid conditions on health-related quality of life (HRQOL) has not been previously examined in the epilepsy literature from the United States. Results from the California Health Interview Survey (CHIS) indicate an increased prevalence of comorbid conditions in persons with a history of epilepsy compared to those without epilepsy. After controlling for demographics and comorbid conditions, persons with a history of epilepsy were significantly more likely to report poor HRQOL. Although seizure freedom should continue to be a primary clinical goal, optimal care should also include primary and secondary prevention of comorbid conditions, especially cardiovascular and pulmonary diseases. Prevention, early identification, and treatment of comorbid conditions may reduce mortality risk and improve health outcomes in persons with epilepsy.

Panayiotopoulos Syndrome: An Important Electroclinical Example of Benign Childhood System Epilepsy

As a result of the converging evidence from multiple large independent studies, Panayiotopoulos syndrome (PS) is now formally recognized as a distinct clinical entity within the spectrum of benign focal epilepsies of childhood. Clinically, PS is manifested by predominantly autonomic seizures and electrographically with multifocal interictal spikes, while the few published ictal recordings have documented onsets of variable lobar topography. These typical electroclinical features do not allow straightforward assignment to a distinctive cortical area, rendering the term "focal"--as we currently understand it--problematic. This is a critical review of the clinical and EEG features of PS, focusing on those characteristics that may shed some light on its so far elusive pathophysiology. We also explore its electroclinical similarities to other idiopathic "focal" epilepsies and its differences to symptomatic focal epilepsies that may also manifest with autonomic ictal symptoms and signs. This methodology allows the formation of a rational hypothesis on the pathophysiology of PS that seems to be emerging as a good model for the so-called "system" (nonsymptomatic) epilepsies, with potentially important taxonomic implications.

Complications of invasive subdural electrode monitoring at St. Louis Children's Hospital, 1994-2005

OBJECT

The purpose of this study was to better define the incidence of complications associated with placement of subdural electrodes for localization of seizure foci and functional mapping in children.

METHODS

The authors retrospectively reviewed the records of 112 consecutive patients (53 boys, 59 girls; mean age 10.9 years, range 10 months-21.7 years) with medically intractable epilepsy who underwent invasive monitoring at the Pediatric Epilepsy Center at St. Louis Children's Hospital between January 1994 and July 2005. There were 122 implantation procedures (85 grids and strips, 32 strips only, five grids only, four with additional depth electrodes), with a mean monitoring period of 7.1 days (range 2-21 days). Operative complications included the need for repeated surgery for additional electrode placement (5.7%); wound infection (2.4%); cerebrospinal fluid leak (1.6%); and subdural hematoma, symptomatic pneumocephalus, bone flap osteomyelitis, and strip electrode fracture requiring operative retrieval (one patient [0.8%] each). There were four cases of transient neurological deficit (3.3%) and no permanent deficit or death associated with invasive monitoring.

CONCLUSIONS

Placement of subdural grid and strip electrodes for invasive video electroencephalographic monitoring is generally well tolerated in the pediatric population. The authors found that aggressive initial electrode coverage was not associated with higher rates of blood transfusion or perioperative complications, and reduced the frequency of repeated operations for placement of supplemental electrodes.

Hemimegalencephaly: clinical implications and surgical treatment

INTRODUCTION

Hemimegalencephaly (HME) is a quite rare malformation of the cortical development arising from an abnormal proliferation of anomalous neuronal and glial cells that generally leads to the hypertrophy of the whole affected cerebral hemisphere. The pathogenesis of such a complex malformation is still unknown even though several hypotheses are reported in literature.

BACKGROUND

HME can occur alone or associated with neurocutaneous disorders, such as neurofibromatosis, epidermal nevus syndrome, Ito's hypomelanosis, and Klippel-Trenonay-Weber syndrome. The clinical picture is usually dominated by a severe and drug-resistant epilepsy. Other common findings are represented by macrocrania, mean/severe mental retardation, unilateral motor deficit, and hemianopia. The EEG shows different abnormal patterns, mainly characterized by suppression burst and/or hemihypsarrhythmia. Although neuroimaging and histologic investigations often show typical findings (enlarged hemisphere, malformed ventricular system, alteration of the normal gyration), the differential diagnosis with other disorders of the neuronal and glial proliferation may be difficult to obtain. Hemispherectomy/hemispherotomy is the most effective treatment to control seizure, and it also seems to provide good results on the psychomotor development when performed early, as demonstrated by the literature review and by the reported personal series reported here (20 children). The surgical therapy of HME, however, is still burdened by a quite high complication rate and mortality risk.

Adolescents' perception of epilepsy compared with other chronic diseases: "through a teenager's eyes"

Adolescent perception of physical and social impact of chronic illness was assessed to determine (1) if there is greater prejudice toward epilepsy than other chronic disease and (2) if adolescents with chronic disease have less prejudice toward similarly affected peers with all types of chronic disease or just their specific chronic disease. Cognitively normal teens aged 13 to 18 years without chronic disease (n = 41) and with epilepsy (n = 32), asthma (n = 38), diabetes (n = 21), and migraine (n = 17) were interviewed in the outpatient clinics of a tertiary care pediatric center regarding their perceptions of the physical and social impact of eight chronic diseases (epilepsy, asthma, diabetes, Down syndrome, arthritis, migraine, leukemia, human immunodeficiency virus [HIV] infection). Epilepsy was perceived to have a more adverse physical impact than all chronic illnesses except Down syndrome. The perception was that it more frequently caused mental handicap, injured the afflicted individual and bystanders, and led to death. Epilepsy was also perceived to have a more negative social impact, particularly on behavior, honesty, popularity, adeptness at sports, and fun. Significantly more adolescents expressed reluctance to befriend peers with epilepsy, both from their own and their perceived parental perspectives. Having a chronic disease did not generally alter the adolescents' perceptions of peers with chronic disease. However, cases with epilepsy ranked this disease to have less social impact than teens with other chronic diseases. In conclusion, adolescents consider epilepsy to have a greater physical and social impact than most chronic diseases. Educational efforts should focus on the "normality" of most persons with epilepsy and emphasize the low risk of injury when proper first aid is followed.

Pediatric Magnetoencephalography and Magnetic Source Imaging

Magnetoencephalography (MEG) and magnetic source imaging (MSI) together represent a uniquely powerful functional imaging modality because of their capabilities of directly observing the electrophysiologic activity of neurons with exquisite temporal detail and accurately localizing corresponding neuromagnetic field sources onto high-resolution MR images. These features have and should continue to advance our understanding of the complex spatiotemporal basis of normal and abnormal brain function and development in children. By more clearly delineating and characterizing epileptogenic foci and their relation to eloquent cortex, MSI enables earlier and more effective neurosurgery to be performed, thus resulting in improved seizure outcomes. Although MEG and MSI cannot replace scalp electroencephalography, neuropsychologic testing, and the need for meticulous intraoperative cortical mapping in patients undergoing excision of epileptogenic lesions, their increasing availability should ultimately persuade many clinicians of their key, if not essential, role in the evaluation and treatment of children with epilepsy.

Forensic issues and possible mechanisms of sudden death in Rett syndrome

A 20-year-old female with an established diagnosis of Rett syndrome was found dead in bed. There had been no history of recent deterioration in health and at autopsy no acute lesions were found. There was no evidence of trauma. Toxicological analysis of blood revealed therapeutic levels of carbamazepine and clonazepam. Death was attributed to the complications of Rett syndrome, an uncommon developmental disorder characterized by autistic type behaviour, hypotonia, stereotyped movements, seizures and growth failure, caused by mutations in the MECP2 gene on the X chromosome. Establishing the precise cause of sudden death in individuals with Rett syndrome may be difficult as epilepsy, defective autonomic nervous system control and cardiac arrhythmias may relate more to functional problems rather than to defects that can be demonstrated at autopsy. Thus, although there are a variety of well-documented underlying mechanisms that may cause sudden death in this condition, determining the exact sequence of events in an unwitnessed death may be more by inference and elimination, given the absence of pathognomonic and acute lethal lesions that are able to be found histopathologically. 'Complications of Rett syndrome' may, therefore, be the most accurate designation when individuals with this condition are found unexpectedly dead and no anatomical cause of death can be identified at autopsy.

Assessment of the role of FDG PET in the diagnosis and management of children with refractory epilepsy

PURPOSE

We performed a retrospective analysis of the results of FDG PET scans in children with refractory epilepsy referred to our centre over an 8-year period, with a view to ascertaining the impact of FDG PET on subsequent patient management.

METHODS

A questionnaire was used to assess the impact of FDG PET scan on diagnosis, management and clinical decision-making processes for epilepsy surgery from the managing clinician's perspective. FDG PET scan results were also compared with MRI, EEG and SPECT results and coded according to whether the FDG PET scan provided independent information and localisation of epileptogenic regions.

RESULTS

A total of 118 eligible patients under the age of 14 years were identified, with questionnaires being completed on 113 evaluable patients (96%). The pre-PET management plan consisted of consideration for surgery in 92 patients (81%) and medical therapy for the remaining 21 patients (19%). Managing physicians rated FDG PET as providing information additional to that obtained with other investigations regarding epileptogenic sites in 88 patients (77%). FDG PET had either a minor or a major impact on clinical management in 58 patients (51%), principally with regard to surgical candidacy.

CONCLUSION

FDG PET has a definite role in the assessment of paediatric patients with refractory epilepsy who are being considered for surgery. In the future, analysis of FDG PET data in specific subpopulations of children with refractory epilepsy may lead to novel insights regarding aetiology.

Sudden unexpected death in epilepsy: a retrospective study

Patients with epilepsy have a mortality rate higher than that of the general population; sudden unexpected death represents a significant category of mortality in these patients. The precise frequency of occurrence of sudden unexpected death in epilepsy (SUDEP) is not well defined, with a range of 1 in 370 to 1100 in the general epileptic population. A major difficulty with incidence studies is the continued reluctance in using the term SUDEP as a cause of death, making reliance solely on death certificates inconsistent and incomplete. Knowledge about SUDEP remains limited, as no single common risk factor has yet been identified, although predisposing conditions have been suggested. The purpose of this study is to review the association between several clinical variables and SUDEP to elucidate risk factors. The characteristics of the 67 cases in this series correlate with published findings in previous studies. Attributes that may be used to define an at-risk group of epileptics include age less than 40 years, male gender, long history of seizure disorder, undermedication or poorly controlled seizure activity, and mental or physical stress. Education of physicians as to the existence of SUDEP and risk factors is imperative in improving patient education and reduction in mortality.

Cerebellar ataxia, seizures, premature death, and cardiac abnormalities in mice with targeted disruption of the Cacna2d2 gene

CACNA2D2 is a putative tumor suppressor gene located in the human chromosome 3p21.3 region that shows frequent allelic imbalances in lung, breast, and other cancers. The alpha2delta-2 protein encoded by the gene is a regulatory subunit of voltage-dependent calcium channels and is expressed in brain, heart, and other tissues. Here we report that mice homozygous for targeted disruption of the Cacna2d2 gene exhibit growth retardation, reduced life span, ataxic gait with apoptosis of cerebellar granule cells followed by Purkinje cell depletion, enhanced susceptibility to seizures, and cardiac abnormalities. The Cacna2d2(tm1NCIF) null phenotype has much in common with that of Cacna1a mutants, such as cerebellar neuro-degeneration associated with ataxia, seizures, and premature death. A tendency to bradycardia and limited response of null mutants to isoflurane implicate alpha2delta-2 in sympathetic regulation of cardiac function. In summary, our findings provide genetic evidence that the alpha2delta-2 subunit serves in vivo as a component of P/Q-type calcium channels, is indispensable for the central nervous system function, and may be involved in hereditary cerebellar ataxias and epileptic disorders in humans.

Characteristics of drowning by different age groups

CONTEXT

While it is known that the risk of unintentional drowning varies with age, the manner in which drowning episode characteristics vary by age has not been well described. Such information might be useful for prevention.

OBJECTIVE

To describe characteristics of drowning by age group.

DESIGN

Retrospective review of the characteristics of drowning victims and their drowning incidents obtained from death certificates, medical examiner, pre-hospital, emergency department, and hospital records.

SETTING

Three counties in Western Washington state.

SUBJECTS

Residents who died (n=709) of unintentional drowning within the study region during 1980 through 1995.

OUTCOMES

Age specific counts, proportions, and rates per million person years were estimated for and compared among six age groups.

RESULTS

Rates varied by age group: 0-4 (30.5), 5-14 (11.6), 15-19 (29.9), 20-34 (21.5), 35-64 (12.5), and 65 years or older (21.2). Among those 0-4 years, the proportions that drowned in pools, bathtubs, and open water were nearly equal. But from age 5-64 years, over 69% of deaths were in open water. Among those 65 years and older, the deaths were almost evenly divided between bathtub and open water; bathtub drowning rates were highest in this age group, 10.9. Pre-drowning activities were divided into boating, swimming, car passenger, bathing, and fell in while doing something else. Most (64/89, 76%) victims aged 0-4 years drowned while bathing or after falling in. Among those 15-19 years, most occurred while swimming (24/79, 34%) or boating (22/79, 31%). The drowning event was least often witnessed among those 0-4 years (10/36, 28%), and most often witnessed (44/58, 76%) among those 15-19 years. Medical care (pre-hospital, emergency department, or hospital) was most often involved in drownings of those 0-4 years (70/89, 79%) and least among those over 65 years (11/86, 13%).

CONCLUSION

The characteristics of drowning episodes vary greatly by age. Different prevention strategies may be needed for different age groups.

Complications of invasive subdural grid monitoring in children with epilepsy

OBJECT

This study was performed to evaluate the complications of invasive subdural grid monitoring during epilepsy surgery in children.

METHODS

The authors retrospectively reviewed the records of 35 consecutive children with intractable localization-related epilepsy who underwent invasive video electroencephalography (EEG) with subdural grid electrodes at The Hospital for Sick Children between 1996 and 2001. After subdural grid monitoring and identification of the epileptic regions, cortical excisions and/or multiple subpial transections (MSTs) were performed. Complications after these procedures were then categorized as either surgical or neurological. There were 17 male and 18 female patients whose mean age was 11.7 years. The duration of epilepsy before surgery ranged from 2 to 17 years (mean 8.3 years). Fifteen children (43%) had previously undergone surgical procedures for epilepsy. The number of electrodes on the grids ranged from 40 to 117 (mean 95). During invasive video EEG, cerebrospinal fluid leaks occurred in seven patients. Also, cerebral edema (five patients), subdural hematoma (five patients), and intracerebral hematoma (three patients) were observed on postprocedural imaging studies but did not require surgical intervention. Hypertrophic scars on the scalp were observed in nine patients. There were three infections, including one case of osteomyelitis and two superficial wound infections. Blood loss and the amounts of subsequent transfusions correlated directly with the size and number of electrodes on the grids (p < 0.001). Twenty-eight children derived significant benefit from cortical resections and MSTs, with a more than 50% reduction of seizures and a mean follow-up period of 30 months.

CONCLUSIONS

The results of this study indicate that carefully selected pediatric patients with intractable epilepsy can benefit from subdural invasive monitoring procedures that entail definite but acceptable risks.

Epilepsy, atherosclerosis, myocardial infarction, and carbamazepine

Epileptic patients receiving medications such as phenytoin or phenobarbital have been noted to have an exceedingly low incidence of myocardial infarction, but children treated with carbamazepine have shown alteration of their serum lipid profile that could predispose them to atherosclerosis. This report seems to corroborate this point and describes the findings in an 11-year-old boy who died following a major seizure, rhabdomyolysis, and renal failure. The autopsy demonstrated that he had marked coronary atherosclerosis and myocardial infarction. The child had been treated with carbamazepine for more than 10 years.