Current state of hemispherectomy and callosotomy for pediatric refractory epilepsy in Denmark

OBJECTIVE

To evaluate outcomes from hemispherectomy and callosotomy related to the need for anti-seizure medication (ASM), seizure frequency, and cognition.

METHODS

A review of the medical charts of all Danish pediatric patients who underwent hemispherectomy or callosotomy from January 1996 to December 2019 for preoperative and postoperative ASM use, seizure frequency, and cognitive data.

RESULTS

The median age of epilepsy onset was two years (interquartile range (IQR): 0.0-5.3) for the hemispherectomy patients (n = 16) and one year (IQR: 0.6-1.7) for callosotomy patients (n = 5). Median time from onset to final surgery was 3.4 years for hemispherectomy and 10.2 years for callosotomy, while the median follow-up time was 6.9 years and 9.0 years, respectively. Preoperatively, all patients had daily seizures and were treated with ≥ 2 ASM. Hemispherectomy resulted in a reduction in seizure frequency in 87.5 % of patients, with 78.6 % achieving seizure freedom. Furthermore, 81.3 % experienced a reduction in ASM use and 56.3 % stopped all ASM. Median IQ/developmental quotient (IQ/DQ) was low preoperatively (44.0 [IQR: 40.0-55.0]) and remained unchanged postoperatively (IQ change: 0.0 [IQR: -10.0-+4.0]). Callosotomy resulted in a seizure reduction of 86-99 % in four patients, and ASM could be reduced in three patients. Median IQ/DQ was 20.0 preoperatively (IQR: 20.0-30.0) and remained unchanged postoperatively (IQ change: 0.0 [IQR: 0.0]).

CONCLUSION

Hemispherectomy and callosotomy result in a substantial reduction in seizure frequency and ASM use without deterioration of IQ. Extensive epilepsy surgery should be considered early in children with drug-resistant epilepsy.

Validation of Pediatric Idiopathic Generalized Epilepsy Diagnoses from the Danish National Patient Register During 1994‒2019

Objective

To identify pediatric idiopathic generalized epilepsy (IGE) during 1994–2019 using ICD-10 codes in the Danish National Patient Register and anti-seizure prescriptions in the Danish Prescription Database.

Study Design and Setting

We reviewed the medical records in children with ICD-10 codes for IGE before 18 years of age, and pediatric neurologists confirmed that the International League Against Epilepsy criteria were met. We estimated positive predictive values (PPV) and sensitivity for ICD-10 alone, including combinations of codes, anti-seizure prescription, and age at first code registration using medical record-validated diagnoses as gold standard.

Results

We validated the medical record in 969 children with an ICD-10 code of IGE, and 431 children had IGE (115 childhood absence epilepsy, 97 juvenile absence epilepsy, 192 juvenile myoclonic epilepsy, 27 generalized tonic-clonic seizures alone). By combining ICD-10 codes with antiseizure prescription and age at epilepsy code registration, we found a PPV for childhood absence epilepsy at 44% (95% confidence interval [CI]=34%‒54%) and for juvenile absence epilepsy at 44% (95% CI=36%–52%). However, ethosuximide prescription, age at ethosuximide code registration before age 8 years and a combination of ICD-10 codes yielded a PPV of 59% (95% CI=42%‒75%) for childhood absence epilepsy but the sensitivity was only 17% (20/115 children identified). For juvenile myoclonic epilepsy the highest PPV was 68% (95% CI=62%‒74%) using the code G40.3F plus antiseizure prescription and age at epilepsy code registration after age 8 years, with sensitivity of 85% (164/192 children identified). For generalized tonic-clonic seizures alone the highest PPV was 31% (95% CI=15%‒51%) using G40.3G during 2006–2019 plus antiseizure prescription and age at code registration after age 5 years.

Conclusion

The Danish National Patient Register and the Danish Prescription Database are not suitable for identifying children with IGE subtypes, except for juvenile myoclonic epilepsy which can be identified with caution.

Epilepsy-Related Mortality in Children and Young Adults in Denmark: A Nationwide Cohort Study

BACKGROUND AND OBJECTIVES

Mortality is increased in epilepsy, but the important issue is that a proportion of epilepsy-related death is potentially preventable by optimized therapy and needs therefore to be identified. A new systematic classification of epilepsy-related mortality has been suggested by Devinsky et al. in 2016 to identify these preventable deaths. We applied this classification to an analysis of premature mortality in persons with epilepsy younger than 50 years.

METHODS

The study was a population-based retrospective cohort of all Danish citizens with and without epilepsy aged 1-49 years during 2007-2009. Information on all deaths was retrieved from the Danish Cause of Death Registry, autopsy reports, death certificates, and the Danish National Patient Registry. The primary cause of death in persons with epilepsy was evaluated independently by three neurologist, one neuro-pediatrician, and two cardiologists. In case of uncertainty a pathologist was consulted. All deaths were classified as either epilepsy- or not-epilepsy-related, and the underlying causes or modes of death were compared between persons with and without epilepsy.

RESULTS

During the study period 700 deaths were identified in persons with epilepsy, and 440 (62.9%) of these were epilepsy-related, hereof, 169 (38%) directly related to seizures and 181 (41%) due to an underlying neurological disease. SUDEP accounted for 80% of deaths directly related to epilepsy. Aspiration pneumonia was the cause of death in 80% of cases indirectly related to epilepsy.Compared with the background population, persons with epilepsy had a nearly four-fold increased all-cause mortality (adjusted mortality hazard ratio of 3.95 [95% CI 3.64-4.27], p<0.0001) and a higher risk of dying from various underlying causes including alcohol-related conditions (hazard ratio of 2.91 [95% CI 2.23-3.80], p<0.0001) and suicide (hazard ratio of 2.10 [95% CI 1.18-3.73], p=0.01).

DISCUSSION

The newly proposed classification for mortality in persons with epilepsy was useful in an unselected nationwide cohort. It helped classifying unnatural causes of death as epilepsy-related or not, and it helped identifying potentially preventable deaths. The leading causes of premature mortality in persons younger than 50 years were related to epilepsy and were thus potentially preventable by good seizure control.

A methodological perspective on the cognitive outcome of epilepsy surgery in children and adolescents

PURPOSE

The purpose of the study was to explore the impact of timing and test specificity of cognitive outcome measures after pediatric epilepsy surgery.

METHODS

A consecutive national cohort of 114 children with medically resistant epilepsy having had resective epilepsy surgery were screened for children tested with a complete age-appropriate Wechsler Intelligence test at two or three time-points. This provided 43 children for analyses. Composite subscale scores were assessed in comparison to index and intelligence quotient (IQ) scores.

RESULTS

We found a main effect of time in seizure-free children for full-scale IQ (FSIQ); F(2, 42) = 6.49 with higher T2 measures compared with T1 (M_Diff = 5.46, p = .006). There was a difference in FSIQ scores between seizure-free and nonseizure-free children at T2; M = 7.31, 95% confidence interval (CI) [0.05 to 14.57], t(38) = 2.04, p = .049, favoring seizure-free children. A statistical difference between composite scale scores and index scores was found with medium to large effect. The correlation of medical treatment (anti-epileptic drug (AED)) change and score differences in FSIQ outcome was significant (p = .041), with less AED correlated with a higher FSIQ. All children with left-temporal surgery had a stable or improved verbal comprehension composite subscale score outcome at T2 regardless of seizure status.

CONCLUSION

Our results correspond to some longitudinal studies with outcome measures >2 years, in contrast to short-term studies ≤2 years with a stable outcome. Our study supports the fact that the specificity of the used tests and the timing of assessments after pediatric epilepsy surgery are essential factors for the clinical validity of outcome measures. However, there are further needs of extensive longitudinal studies to provide a better understanding of life-long cognitive development and impact after childhood epilepsy surgery.

Increase in cognitive function is seen in many single-operated pediatric patients after epilepsy surgery

PURPOSE

The recurrent seizures of pediatric drug-resistant epilepsy (DRE) are known to impair brain development and can lead to a loss in cognitive functioning. Surgery is increasingly being used to treat children with DRE. This study investigates the pre- and postoperative cognitive function in a pediatric epilepsy surgery cohort as well as predictive determinants of change in intelligence quotient (IQ) following surgery.

METHODS

A consecutive series of 91 Danish children who underwent focal resective epilepsy surgery between January 1996 and December 2016 were included. All underwent preoperative cognitive evaluation and were reevaluated at 1-year and/or 2-year follow-up. Single-operated and multi-operated patients were examined separately.

RESULTS

79 of 91 patients were single-operated. Single-operated patients received less anti-epileptic drugs (AED) and experienced a decrease in seizure frequency postoperatively, p < 0.001. IQ increased postoperatively (IQ change ± standard deviation: 3.3 ± 14.0), p < 0.05. High preoperative seizure frequency was a significant predictor for decreased IQ, p < 0.01. Multi-operated patients did not experience a reduction in AED treatment. Surgery and continued AED treatment did, however, result in significantly better seizure control, p < 0.01. IQ remained unchanged in multi-operated patients.

CONCLUSION

Epilepsy surgery allowed for IQ gains in single-operated patients. Preoperative seizure frequency was a significant predictor of IQ change following surgery. Interactions between other, not included, possible predictors remain to be examined. Single-operated patients had the best cognitive outcome. The inclusion of a non-surgical control group is needed to assess the extent of the beneficial effects of surgery on cognitive ability.

Increased cerebrospinal fluid chitinase 3-like 1 and neurofilament light chain in pediatric acquired demyelinating syndromes

BACKGROUND

Chitinase 3-like 1 (CHI3L1), neurofilament light chain (NFL) and oligoclonal bands (OCB) in cerebrospinal fluid are associated with central nervous system demyelination in adults. CHI3L1 and OCB are markers of central nervous system inflammation, whereas NFL is a marker of white-matter axonal injury. The aim was to examine whether CHI3L1 and NFL in cerebrospinal fluid are associated with acquired demyelinating syndromes at disease onset in a pediatric population.

METHODS

Children (<18 years) referred to hospital for possible neuroinflammatory disease were retrospectively included from 2010 to 2016. Case ascertainment was by review of medical records. NFL and CHI3L1 were measured by enzyme-linked immunosorbent assays. Endpoints were differences in concentrations of cerebrospinal fluid NFL and CHI3L1.

RESULTS

We included 193 children who all underwent cerebrospinal fluid OCB examination as part of their diagnostic work-up and classified these children into 5 groups: acquired demyelinating syndromes (n = 33), normal diagnostic work-up (n = 36), inflammatory neurological disease (n = 50), other neurological disease (n = 55), and systemic inflammatory diseases (n = 19). NFL and CHI3L1 in cerebrospinal fluid differed significantly between the five groups (p = 0.0001). CHI3L1 was significantly higher in acquired demyelinating syndromes than in all other groups, and NFL was significantly higher in acquired demyelinating syndromes than in the other groups except systemic inflammatory disease. Children with acute disseminated encephalomyelitis had significantly higher concentrations of CHI3L1 than did children with multiple sclerosis.

CONCLUSION

We provide class II evidence that CHI3L1 and NFL are associated with pediatric acquired demyelinating syndromes. CHI3L1 may help distinguishing between acute disseminated encephalomyelitis and multiple sclerosis, but this needs further confirmation.

Infections seem to be more frequent before onset of pediatric multiple sclerosis: A Danish nationwide nested case–control study

Background:

Infections are suspected environmental triggers for multiple sclerosis (MS). The relationship between the timing and cumulative number of childhood infections regarding pediatric MS risk is uninvestigated.

Objectives:

To investigate whether childhood infections contribute to pediatric MS.

Methods:

A nationwide nested case–control study with detailed MS case ascertainment including chart review was undertaken. For each MS case, we selected five control children using density sampling from the entire Danish population, matching controls to children with MS by sex and birthdate. We analyzed data with the cumulative number of childhood infections as exposure and MS as outcome. Hazard ratios (HRs) including 95% confidence intervals (CIs) were estimated using Cox regression.

Results:

We identified 212 children with MS and 1,060 controls. Median age at MS onset was 15.3 years (range: 7.6–17.8 years); 72% were girls. Each infection during the preceding 3 years increased the hazard for MS by 11% (95% CI = 1.01–1.22, p = 0.04); having 5+ infections compared with 0–4 infections in the preceding 3 years doubled the hazard for MS (HR: 2.18; 95% CI = 1.12–4.30, p = 0.02).

Conclusion:

Children with MS appeared to have more infections in the 3 years preceding MS clinical onset; accordingly, immune response to infections may influence MS pathogenesis.

Post-varicella Arterial Ischemic Stroke in Denmark 2010 to 2016

BACKGROUND

Varicella, most often a benign disease of childhood, is associated with an increased risk of arterial ischemic stroke in children. The aim of the present study was to estimate the incidence of post-varicella arterial ischemic stroke in the Danish child population and describe clinical characteristics of children admitted with post-varicella arterial ischemic stroke.

METHODS

In the Danish National Patient Register, we identified inpatients 28 days to 16 years of age with a discharge diagnosis of stroke or cerebrovascular disease from 2010 to 2016. Medical files were reviewed, and children with arterial ischemic stroke and varicella infection less than 12 months before onset of symptoms were included.

RESULTS

We identified 15 children with arterial ischemic stroke and varicella less than 12 months before. In nine children, the diagnosis was confirmed by detection of varicella zoster virus DNA or varicella zoster virus immunoglobulin G in the cerebrospinal fluid. All children were previously healthy, the mean age was four years, and 67% were male. The median time from varicella rash to arterial ischemic stroke was 4.6 months. The most common location of arterial ischemic stroke was the basal ganglia, and affected vessels were most often in the anterior circulation. Fifty-three percent experienced neurological sequelae of varying degree.

CONCLUSIONS

In Denmark, where varicella vaccination is not part of the childhood vaccination program, the estimated risk of post-varicella arterial ischemic stroke was one case (including possible cases) per 26,000 children with varicella.

[Cannabis is not for children or adolescents]

The Danish parliament has decided to establish a four-year pilot scheme for medical treatment with cannabis. We increasingly experience requests from parents for medical treatment with cannabis of children and have the impression that a growing number of parents treat their children with illegally acquired cannabis products for various conditions. We summarize the sparse evidence regarding effects, side effects and long-term effects of medical treatment with cannabis in children and adolescents. At present, cannabis should very rarely be considered as part of medical treatment for children and adolescents.

Pediatric-onset multiple sclerosis and other acquired demyelinating syndromes of the central nervous system in Denmark during 1977-2015: A nationwide population-based incidence study

BACKGROUND

The incidence of acquired demyelinating syndromes (ADS) including multiple sclerosis (MS) has never been investigated in a Danish pediatric population.

OBJECTIVES

We estimated the nationwide age- and sex-specific incidence of pediatric ADS including MS.

METHODS

Data were sourced from the Danish Multiple Sclerosis Registry, providing cases of pediatric MS for 1977-2015, and the National Patient Register, providing cases of ADS during 2008-2015. All medical records were reviewed to validate the register-based diagnoses.

RESULTS

We identified 364 cases of pediatric MS occurring during 1977-2015 (incidence rate = 0.79 per 100,000 person-years). MS was exceptionally rare before puberty, but the incidence rose considerably from 9 years in girls and 11 years in boys. The female-to-male ratio was 2.5; the median age at onset was 16 years (range = 7-17 years). The MS incidence rate was relatively stable through the study period. During 2008-2015, we identified 219 ADS cases. The incidence was 2.29 per 100,000 person-years with considerable differences in the age peaks for the separate ADS.

CONCLUSION

The incidence rates of MS and other ADS in Denmark were higher than those reported for some other European countries. Referral bias and classification differences may account for this disparity, in particular the age-intervals and the definition of onset.

A child with myoclonus-dystonia (DYT11) misdiagnosed as atypical opsoclonus myoclonus syndrome

INTRODUCTION

DYT11 is an autosomal dominant inherited movement disorder characterized by myoclonus and dystonia.

CLINICAL PRESENTATION

We present a case with atypical symptoms and with episodes of ataxia and myoclonus preceded by infections. Atypical presentation of opsoclonus myoclonus syndrome was suspected and treatment with bolus steroids and immunoglobulin were initiated with some response over 28 months. A re-evaluation gave suspicion of a dyskinetic disorder and whole exome-sequencing was performed but no causal variant was identified.

OUTCOME

A specific analysis of the SGCE gene was subsequently initiated, which revealed a pathogenic aberration confirming the diagnosis of DYT11.

CONCLUSION

A clinical DYT11 diagnosis can be difficult to establish in early childhood without a known family history.

[Congenital bilateral perisylvian syndrome]

The congenital bilateral perisylvian syndrome is characterized by pseudobulbar palsy, moderate delay in mental and motor development and epilepsy. Three characteristic case stories are presented. Epileptic seizures are most frequently generalized: tonic, astatic, atypical absences and tonic-clonic seizures. Partial seizures are less frequent. Seizure control is often unsatisfactory. Neuroimaging demonstrates thickening of the cerebral cortex in the perisylvian area bilaterally; these changes together with the clinical picture establish the diagnosis. The etiology is unknown.

[Treatment of childhood epilepsy with lamotrigine. An evaluation of efficacy in different types of epilepsy]

Fifty-two children with intractable epilepsy received lamotrigine as add-on therapy on a compassionate basis. The results were reviewed after three and six months of treatment in order to evaluate the efficacy in different epilepsy syndromes. Mental retardation was present in 60% of the children. Ictal EEG was obtained in 38 children. At three months the median monthly seizure frequency was reduced from 46 to 14 in the 37 children that still received lamotrigine (p < 0.01). Seven children were seizure-free. Seizure reduction was most impressive in generalized epilepsy, since 63% of these had more than 50% seizure reduction compared to 18% in partial epilepsies (p < 0.05). This difference was unchanged after six months of treatment. Side effects were reported in 18 of the children. In 13 children the parents reported an improved wellbeing. Lamotrigine seems to be an efficient antiepileptic drug-especially in generalized epilepsy.

[Congenital cerebral paresis in Eastern Denmark, the year of birth between 1971-1982]

The aim of The Cerebral Palsy Register is to follow the development of cerebral palsy in East Denmark as reported from the children's departments within the area. The prevalence among Danish children born in 1971-1982 is reported. Postnatal cases have been excluded. The live-birth prevalence has increased from 1.7 per 1000 in 1971-1974 to 2.3 per 1000 in 1979-1982. An increased proportion with birthweight under 2500 g and neuroimpairment was found in the latest birth year period. A re-evaluation of diagnostic information confirmed the increasing trend of the prevalence. Preterm births were dominated by perinatal etiology, while term births equally often had a prenatal etiology. It is worrying that the prevalence is rising and that the children have more disabilities. The reason for the increasing trend is most probably due to the decreasing neonatal mortality.

[Pseudoepileptic seizures in children]

Pseudoepileptic seizures (pseudoseizures) are defined as episodic disturbances of behaviour with elements of epileptic seizures, but with atypical features and not accompanied by abnormal EEG discharges. They are frequently seen in patients with epilepsy, but also as the only disturbance of function. In children, the possible pathogenetic mechanisms are less understood than in adults. We present a series of cases, showing that an important factor in development of pseudoseizures lies in disturbances of communication between children and parents within the family. However, there are large interindividual variations in the most probable underlying mechanisms. Some recommendations as regards treatment are given.