Cenobamate in Generalized Epilepsy and Combined Generalized and Focal Epilepsy

Background and Objectives

Cenobamate (CNB) is a United States Food and Drug Administration–approved antiseizure medication (ASM) for focal-onset seizures; however, its potential clinical effectiveness as a broad-spectrum ASM is not established. CNB has a proposed dual mechanism of action with preferential blockade of persistent sodium currents and positive allosteric modulation of the γ-aminobutyric acid-A (GABA-A) receptor. We evaluated the efficacy of CNB in drug refractory patients with genetic generalized epilepsies (GGE) or combined generalized and focal epilepsies (CGFE), including developmental and epileptic encephalopathies.

Methods

We performed a retrospective review and identified the following: cohort 1 (n = 4) with GGE, of which 2 patients had idiopathic generalized epilepsy, and cohort 2 with CGFE (n = 9), of which 4 patients had Lennox-Gastaut syndrome and 1 had Dravet syndrome.

Results

In cohort 1, all 3 patients with frequent generalized tonic-clonic seizures (GTCs) had a greater than 50% reduction in GTCs. In cohort 2, reduction in both generalized and focal-onset seizures was noted. In these groups together, the mean reduction of all seizure types was 58%, and ≥50% responder rate was 70% (SD = ±34.16, median = 50%). No worsening of generalized-onset seizures occurred in either cohort. Seventy-seven percent of patients experienced side effects, warranting a modification of treatment managed by slower titration, dose reduction of CNB, or discontinuing other ASMs.

Discussion

In our retrospective case series, CNB seems to be an effective ASM for patients with drug-resistant GGE and CGFE. The ongoing CNB trial assessing effectiveness for primary GTCs will provide more data on generalized-onset seizures.

Classification of Evidence

This study provides Class IV evidence that CNB in generalized epilepsy and combined generalized and focal epilepsy reduces seizure frequency.

Fenfluramine provides clinically meaningful reduction in frequency of drop seizures in patients with Lennox-Gastaut syndrome: Interim analysis of an open-label extension study

OBJECTIVE

This study was undertaken to evaluate the long-term safety and effectiveness of fenfluramine in patients with Lennox-Gastaut syndrome (LGS).

METHODS

Eligible patients with LGS who completed a 14-week phase 3 randomized clinical trial enrolled in an open-label extension (OLE; NCT03355209). All patients were initially started on .2 mg/kg/day fenfluramine and after 1 month were titrated by effectiveness and tolerability, which were assessed at 3-month intervals. The protocol-specified treatment duration was 12 months, but COVID-19-related delays resulted in 142 patients completing their final visit after 12 months.

RESULTS

As of October 19, 2020, 247 patients were enrolled in the OLE. Mean age was 14.3 ± 7.6 years (79 [32%] adults) and median fenfluramine treatment duration was 364 days; 88.3% of patients received 2-4 concomitant antiseizure medications. Median percentage change in monthly drop seizure frequency was -28.6% over the entire OLE (n = 241) and -50.5% at Month 15 (n = 142, p < .0001); 75 of 241 patients (31.1%) experienced ≥50% reduction in drop seizure frequency. Median percentage change in nondrop seizure frequency was -45.9% (n = 192, p = .0038). Generalized tonic-clonic seizures (GTCS) and tonic seizures were most responsive to treatment, with median reductions over the entire OLE of 48.8% (p < .0001, n = 106) and 35.8% (p < .0001, n = 186), respectively. A total of 37.6% (95% confidence interval [CI] = 31.4%-44.1%, n = 237) of investigators and 35.2% of caregivers (95% CI = 29.1%-41.8%, n = 230) rated patients as Much Improved/Very Much Improved on the Clinical Global Impression of Improvement scale. The most frequent treatment-emergent adverse events were decreased appetite (16.2%) and fatigue (13.4%). No cases of valvular heart disease (VHD) or pulmonary arterial hypertension (PAH) were observed.

SIGNIFICANCE

Patients with LGS experienced sustained reductions in drop seizure frequency on fenfluramine treatment, with a particularly robust reduction in frequency of GTCS, the key risk factor for sudden unexpected death in epilepsy. Fenfluramine was generally well tolerated; VHD or PAH was not observed long-term. Fenfluramine may provide an important long-term treatment option for LGS.

Temporal Encephalocele: A Treatable Etiology of Drug-Resistant Pediatric Temporal Lobe Epilepsy

BACKGROUND

Temporal lobe encephaloceles (TEs) are a rare cause of drug-resistant temporal lobe epilepsy (DR-TLE), with head trauma and obesity identified as risk factors in adults. This study evaluated the clinical characteristics of childhood-onset DR-TLE due to TE.

METHODS

This is a single-institution retrospective review of childhood-onset DR-TLE with radiographic TE identified between 2008 and 2020. The epilepsy history, brain imaging features, and surgical outcomes were collected.

RESULTS

Eleven children with DR-TLE due to TE were included (median age at epilepsy onset was 11 years, interquartile range 8.5 to 13.5 years). Median latency between epilepsy diagnosis and TE detection was 3 years (range of 0 to 13 years). None had history of head trauma. Body mass index greater than 85 percentile for age and sex was seen in 36% of the children. No patient had bilateral TE identified. TEs were diagnosed based on epilepsy surgery conference re-review of imaging in 36% of cases. All herniations were contained defects without osseous dehiscence. Regional fluorodeoxyglucose (FDG) hypometabolism ipsilateral to the encephalocele was seen in all children who had FDG-positron emission tomography (PET) of the brain. Of the children who had surgery, 70% were seizure free or had nondisabling seizures at last follow-up (mean follow-up 52 months).

CONCLUSIONS

TE is a surgically remediable etiology of DR-TLE in childhood. TEs are often overlooked at pediatric epilepsy diagnosis, calling for the need to increase awareness of this entity. FDG-PET temporal hypometabolism in children with presumed nonlesional DR-TLE should be carefully examined for occult TEs.

Efficacy and Safety of Fenfluramine for the Treatment of Seizures Associated With Lennox-Gastaut Syndrome: A Randomized Clinical Trial

Question

Is adjunctive fenfluramine effective in patients with Lennox-Gastaut syndrome (LGS)?

Findings

In this randomized clinical trial of 263 patients with LGS, use of 0.7-mg/kg/d fenfluramine resulted in a greater reduction in drop seizures than with placebo, more patients achieving a 50% or greater reduction in drop seizure frequency, and greater reduction in generalized tonic-clonic seizure frequency. Treatment-emergent adverse events included decreased appetite, but no patient developed valvular heart disease or pulmonary hypertension.

Meaning

Findings from this trial suggest that fenfluramine may be a safe and effective treatment option for patients with LGS.

Importance

New treatment options are needed for patients with Lennox-Gastaut syndrome (LGS), a profoundly impairing, treatment-resistant, developmental and epileptic encephalopathy.

Objective

To evaluate the efficacy and safety of fenfluramine in patients with LGS.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled, parallel-group randomized clinical trial was conducted from November 27, 2017, to October 25, 2019, and had a 20-week trial duration. Patients were enrolled at 65 study sites in North America, Europe, and Australia. Included patients were aged 2 to 35 years with confirmed diagnosis of LGS and experienced 2 or more drop seizures per week during the 4-week baseline. Using a modified intent-to-treat method, data analysis was performed from November 27, 2017, to October 25, 2019. The database lock date was January 30, 2020, and the date of final report was September 11, 2021.

Interventions

Patients were randomized to receive either a 0.7-mg/kg/d or 0.2-mg/kg/d (maximum 26 mg/d) dose of fenfluramine or placebo. After titration (2-week period), patients were taking their randomized dose for 12 additional weeks.

Main Outcomes and Measures

Primary efficacy end point was percentage change from baseline in drop seizure frequency in patients who received 0.7 mg/kg/d of fenfluramine vs placebo.

Results

A total of 263 patients (median [range] age, 13 [2-35] years; 146 male patients [56%]) were randomized to the 0.7-mg/kg/d fenfluramine group (n = 87), 0.2-mg/kg/d fenfluramine group (n = 89), or placebo group (n = 87). The median percentage reduction in frequency of drop seizures was 26.5 percentage points in the 0.7-mg/kg/d fenfluramine group, 14.2 percentage points in the 0.2-mg/kg/d fenfluramine group, and 7.6 percentage points in the placebo group. The trial met its primary efficacy end point: patients in the 0.7-mg/kg/d fenfluramine group achieved a −19.9 percentage points (95% CI, −31.0 to −8.7 percentage points; P = .001) estimated median difference in drop seizures from baseline vs placebo. More patients in the 0.7-mg/kg/d fenfluramine group achieved a 50% or greater response (22 of 87 [25%]; P = .02) vs placebo (9 of 87 [10%]). Site investigators and caregivers gave a much improved or very much improved rating on the Clinical Global Impression of Improvement scale to more patients in the 0.7-mg/kg/d fenfluramine group than patients in the placebo group (21 [26%] vs 5 [6%]; P = .001). The seizure subtype that appeared most responsive to fenfluramine was generalized tonic-clonic seizure (120 of 263 [46%]), with a decrease in frequency of 45.7% in the 0.7-mg/kg/d fenfluramine group and 58.2% in the 0.2-mg/kg/d fenfluramine group compared with an increase of 3.7% in the placebo group. Most common treatment-emergent adverse events included decreased appetite (59 [22%]), somnolence (33 [13%]), and fatigue (33 [13%]). No cases of valvular heart disease or pulmonary arterial hypertension were observed.

Conclusions and Relevance

Results of this trial showed that, in patients with LGS, fenfluramine compared with placebo provided a significantly greater reduction in drop seizures and may be a particularly advantageous choice in patients who experience generalized tonic-clonic seizures.

Trial Registration

ClinicalTrials.gov Identifier: NCT03355209

Safety and efficacy of responsive neurostimulation in the pediatric population: Evidence from institutional review and patient-level meta-analysis

BACKGROUND

Responsive neurostimulation (RNS) is a novel technology for drug-resistant epilepsy rising from bilateral hemispheres or eloquent cortex. Although recently approved for adults, its safety and efficacy for pediatric patients is under investigation.

METHODS

A comprehensive literature search (Pubmed/Medline, Scopus, Cochrane) was conducted for studies on RNS for pediatric epilepsy (<18 y/o) and supplemented by our institutional series (4 cases). Reduction in seizure frequency at last follow-up compared to preoperative baseline comprised the primary endpoint.

RESULTS

A total of 8 studies (49 patients) were analyzed. Median age at implant was 15 years (interquartile range [IQR] 12-17) and 63% were males. A lesional MRI was noted in 64% (14/22). Prior invasive EEG recording was performed in the majority of patients (90%) and the most common modality was stereoelectroencephalography (57%). The most common implant location (total of 94 RNS leads) was the frontal lobe (27%), followed by mesial temporal structures (23%) and thalamus (17%). At a median follow-up of 22 months, median seizure frequency reduction was 75% (IQR: 50-88%) and 80% were responders (>50% seizure reduction). Responses ranged from 50% for temporal lobe epilepsy to 81-93% for frontal, parietal, and multilobar epilepsy. Four infections were observed (8%) and there were no hematomas or postoperative neurological deficits.

CONCLUSION

Current evidence, albeit limited by potential publication bias, supports the promising safety and efficacy profile of RNS for medically refractory pediatric epilepsy. Randomized controlled trial data are needed to further establish the role of this intervention in preoperative discussions with patients and their families.

Masking for School-Age Children With Epilepsy: We Do Have Consensus!

INTRODUCTION

This study was designed to assess current recommendations from child neurologists and epileptologists on masking for school-age children with epilepsy.

METHODS

A 7-item survey was created and sent out to members of the Child Neurology Society and Pediatric Epilepsy Research Consortium in August of 2021 to assess current practice and provider recommendations on masking.

RESULTS

One hundred four individuals participated with representation from all regions of the United States. Masking was recommended by 95.1%, with 63.4% (n = 66) noting exception of those with severe intellectual disability, autism, and behavioral problems. Of those who write exemption letters, 54% write these <5% of the time. Only 3% reported potential adverse events associated with masking.

CONCLUSION

Nearly all respondents recommended masking for school-age children with epilepsy. Potential risks of masking and adverse events were low. Improved guidance on masking is needed to ensure academic success of our patients with epilepsy.

Pediatric EEG

Electroencephalography (EEG) is an important part of the evaluation of many disorders in infants and children. However, differentiating abnormalities from normal maturational changes and benign variants can be challenging. There are also age-specific recording requirements, including acceptable duration of recording, as well as need for recording of additional physiological variables. In preterm and term infants, it is essential to determine conceptional age to determine whether the EEG patterns are appropriate for age and record at least two physiological variables in addition to the EEG. In infants and children, there is considerable variability regarding the amount of alpha, theta, and delta present, requiring an understanding of the broad ranges of normal backgrounds for each age group. Finally, as the child matures and transitions to adulthood, there are benign variants that can easily be misinterpreted as potentially epileptiform. To be able to correctly identify EEG abnormalities in children, one must be aware of the normal EEG patterns for each age group.

Management of Infantile Spasms During the COVID-19 Pandemic

Circumstances of the COVID-19 pandemic have mandated a change to standard management of infantile spasms. On April 6, 2020, the Child Neurology Society issued an online statement of immediate recommendations to streamline diagnosis and treatment of infantile spasms with utilization of telemedicine, outpatient studies, and selection of first-line oral therapies as initial treatment. The rationale for the recommendations and specific guidance including follow-up assessment are provided in this manuscript. These recommendations are indicated as enduring if intended to outlast the pandemic, and limited if intended only for the pandemic health care crisis but may be applicable to future disruptions of health care delivery.

Refinement of the clinical and mutational spectrum of UBE2A deficiency syndrome

UBE2A deficiency, that is, intellectual disability (ID) Nascimento type (MIM 300860), is an X-linked syndrome characterized by developmental delay, moderate to severe ID, seizures, dysmorphisms, skin anomalies, and urogenital malformations. Forty affected subjects have been reported thus far, with 31 cases having intragenic UBE2A variants. Here, we report on additional eight affected subjects from seven unrelated families who were found to be hemizygous for previously unreported UBE2A missense variants (p.Glu62Lys, p.Arg95Cys, p.Thr99Ala, and p.Arg135Trp) or small in-frame deletions (p.Val81_Ala83del, and p.Asp101del). A wide phenotypic spectrum was documented in these subjects, ranging from moderate ID associated with mild dysmorphisms to severe features including congenital heart defects (CHD), severe cognitive impairment, and pineal gland tumors. Four variants affected residues (Glu62, Arg95, Thr99 and Asp101) that contribute to stabilizing the structure of the E3 binding domain. The three-residue in-frame deletion, p.Val81_Ala83del, resulted from aberrant processing of the transcript. This variant and p.Arg135Trp mapped to regions of the protein located far from the E3 binding region, and caused variably accelerated protein degradation. By reviewing available clinical information, we revise the clinical and molecular profile of the disorder and document genotype-phenotype correlations. Pineal gland cysts/tumors, CHD and hypogammaglobulinemia emerge as recurrent features.

The Ketogenic and Modified Atkins Diet Therapy for Children With Refractory Epilepsy of Genetic Etiology

BACKGROUND

The ketogenic diet is an accepted treatment modality in refractory childhood epilepsy. In this study, we analyzed the efficacy and tolerability of the ketogenic and modified Atkins diets in children with refractory epilepsy of genetic etiology and studied the effect of the diet on seizure frequency.

METHODS

The records of children with a genetic etiology for refractory epilepsy treated with ketogenic and modified Atkins diet between September 2005 and July 2016 were reviewed. We documented age of seizure and diet onset, seizure characteristics, and specific genetic etiology. The proportion of children remaining on the diet and responder rates (greater than 50% seizure reduction) were noted at one, three, six, 12, and 24 months after diet initiation. Tolerability and safety profile were also recorded.

RESULTS

Fifty-nine children with a genetic etiology (63% females, median age at diet onset 2.2 years) were initiated on the diet at our center. Fifty-three (90%) were started on a traditional ketogenic diet, whereas six started a modified Atkins diet. The adverse events at the initiation of diet were vomiting (24%), hypoglycemia (15%), and refusal to feed (11%). Three children stopped the diet before discharge because of poor compliance, severe reflux, and ketoacidosis (n = 1 each). The proportion of children remaining on the diet at one, three, six, 12, and 24 months was 95%, 86%, 69%, 64%, and 47%. The responder rates were 63%, 61%, 54%, 53%, and 41% at one, three, six, 12, and 24 months, respectively.

CONCLUSIONS

The ketogenic diet is an effective treatment modality in children with refractory epilepsy of genetic etiology.

Jeavons Syndrome: Clinical Features and Response to Treatment

BACKGROUND

Jeavons syndrome is an underreported epileptic syndrome characterized by eyelid myoclonia, eyelid closure-induced seizures or electroencephalography paroxysms, and photosensitivity. Drug-resistant epilepsy is common, but the prognostic factors and clinical course leading to drug resistance have not been well characterized.

METHODS

We identified 30 patients who met the diagnostic criteria of Jeavons syndrome at a single institution between January 1, 2000 and December 15, 2016. Criteria for Jeavons syndrome included all of the following: (1) eyelid myoclonia with or without absences, (2) eye-closure-induced seizures or electroencephalography paroxysms, and (3) seizure onset after 12 months of age. We reviewed and described the epilepsy history, antiepileptic drug trials, and response to treatments.

RESULTS

Mean age at seizure onset was 7.3 years, and 80% were female. Absence seizures (63%) and generalized tonic-clonic seizures (23%) were most common at onset. Diagnosis was delayed by an average of 9.6 years. After a median follow-up of two years, 80% of patients had drug resistant epilepsy and 70% experienced generalized tonic-clonic seizures. Generalized tonic-clonic seizures and seizure types other than absence seizures increased the risk of drug-resistant epilepsy (P values 0.049 and 0.03, respectively). Valproic acid, lamotrigine, ethosuximide, and levetiracetam were the most effective in reducing seizures by more than 50%.

CONCLUSIONS

The diagnosis of Jeavons syndrome is often delayed. Generalized tonic-clonic seizures and seizure types other than absence seizures may be predictors of drug-resistant epilepsy among patients with Jeavons syndrome.

Impact of Prior Authorization of Antiepileptic Drugs in Children With Epilepsy

OBJECTIVE

We assessed how commonly prior authorization results in treatment delay or missed doses in children with epilepsy.

METHODS

Parents of 462 children followed in a pediatric epilepsy clinic were surveyed regarding prior authorization in the preceding year. Epilepsy and insurance details were collected. If prior authorization was required, parents were asked whether it resulted in (1) delayed initiation of a newly-prescribed antiepileptic drug, and/or (2) lapse in coverage of a current medication. Prior authorization was defined as smooth if there was a less than seven day delay in starting a new antiepileptic drug and no lapse in coverage of a current medication.

RESULTS

A total of 164 families (35%) returned completed surveys. Mean age of the children was 11.2 (S.D. 5.3) years and 67.4% experienced seizures more than every three months despite trials of two or more antiepileptic drugs. Primary insurance was private in 82.9% and Medicaid in 15.2%. Prior authorization was required in 63 (38.4%) cases, and proceeded smoothly in only 31 (49.2%). Twenty-three children experienced a delay of seven days or more in starting a new drug, and 24 experienced a lapse in coverage of their current medication, 11 of whom missed doses. Of these 11, seven had increased seizures, and one required hospital admission for status epilepticus.

CONCLUSIONS

Prior authorization of antiepileptic drugs is common but problematic, often resulting in either a delay of initiation of a new antiepileptic drug or a lapse in coverage of a currently-used antiepileptic drug, with a negative impact on seizure control.

The impact of hypsarrhythmia on infantile spasms treatment response: Observational cohort study from the National Infantile Spasms Consortium

OBJECTIVE

The multicenter National Infantile Spasms Consortium prospective cohort was used to compare outcomes and phenotypic features of patients with infantile spasms with and without hypsarrhythmia.

METHODS

Patients aged 2 months to 2 years were enrolled prospectively with new-onset infantile spasms. Treatment choice and categorization of hypsarrhythmia were determined clinically at each site. Response to therapy was defined as resolution of clinical spasms (and hypsarrhythmia if present) without relapse 3 months after initiation.

RESULTS

Eighty-two percent of patients had hypsarrhythmia, but this was not associated with gender, mean age, preexisting developmental delay or epilepsy, etiology, or response to first-line therapy. Infants with hypsarrhythmia were more likely to receive standard treatment (adrenocorticotropic hormone, prednisolone, or vigabatrin [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.4-4.7] and preexisting epilepsy reduced the likelihood of standard treatment (OR 3.2, 95% CI 1.9-5.4). Hypsarrhythmia was not a determinant of response to treatment. A logistic regression model demonstrated that later age of onset (OR 1.09 per month, 95% CI 1.03-1.15) and absence of preexisting epilepsy (OR 1.7, 95% CI 1.06-2.81) had a small impact on the likelihood of responding to the first-line treatment. However, receiving standard first-line treatment increased the likelihood of responding dramatically: vigabatrin (OR 5.2 ,95% CI 2-13.7), prednisolone (OR 8, 95% CI 3.1-20.6), and adrenocorticotropic hormone (ACTH; OR 10.2, 95% CI 4.1-25.8) .

SIGNIFICANCE

First-line treatment with standard therapy was by far the most important variable in determining likelihood of response to treatment of infantile spasms with or without hypsarrhythmia.

Cognitive and Social Outcomes of Epileptic Encephalopathies

The term "epileptic encephalopathy" denotes a disorder in which seizures or frequent interictal discharges exacerbate neurocognitive dysfunction beyond what would be expected on the basis of underlying etiology. However, many underlying causes of epileptic encephalopathy also result in neurocognitive deficits, and it can be challenging to discern to what extent these deficits can be improved with better seizure control. Additionally, as seizures in these conditions are typically refractory, children are often exposed to high doses of multiple antiepileptic drugs which further exacerbate these comorbidities. This review will summarize the neurocognitive and social outcomes in children with various epileptic encephalopathies. Prompt, accurate diagnosis of epilepsy syndrome and etiology allows selection of optimal therapy to maximize seizure control, limiting the impact of ongoing seizures and frequent epileptiform abnormalities on the developing brain. Furthermore, mandatory screening for comorbidities allows early recognition and focused therapy for these commonly associated conditions to maximize neurocognitive outcome.

Not all SCN1A epileptic encephalopathies are Dravet syndrome: Early profound Thr226Met phenotype

Objective:

To define a distinct SCN1A developmental and epileptic encephalopathy with early onset, profound impairment, and movement disorder.

Methods:

A case series of 9 children were identified with a profound developmental and epileptic encephalopathy and SCN1A mutation.

Results:

We identified 9 children 3 to 12 years of age; 7 were male. Seizure onset was at 6 to 12 weeks with hemiclonic seizures, bilateral tonic-clonic seizures, or spasms. All children had profound developmental impairment and were nonverbal and nonambulatory, and 7 of 9 required a gastrostomy. A hyperkinetic movement disorder occurred in all and was characterized by dystonia and choreoathetosis with prominent oral dyskinesia and onset from 2 to 20 months of age. Eight had a recurrent missense SCN1A mutation, p.Thr226Met. The remaining child had the missense mutation p.Pro1345Ser. The mutation arose de novo in 8 of 9; for the remaining case, the mother was negative and the father was unavailable.

Conclusions:

Here, we present a phenotype-genotype correlation for SCN1A. We describe a distinct SCN1A phenotype, early infantile SCN1A encephalopathy, which is readily distinguishable from the well-recognized entities of Dravet syndrome and genetic epilepsy with febrile seizures plus. This disorder has an earlier age at onset, profound developmental impairment, and a distinctive hyperkinetic movement disorder, setting it apart from Dravet syndrome. Remarkably, 8 of 9 children had the recurrent missense mutation p.Thr226Met.

Stiripentol in the Management of Epilepsy

Stiripentol is a structurally unique antiepileptic drug that has several possible mechanisms of action, including diverse effects on the gamma-aminobutyric acid (GABA)-_A receptor and novel inhibition of lactate dehydrogenase. Because of its inhibition of several cytochrome P450 enzymes, it has extensive pharmacokinetic interactions, which often necessitates reduction in doses of certain co-therapies, particularly clobazam. Stiripentol also has a neuroprotective action, by reducing calcium-mediated neurotoxicity. Evidence of its efficacy is most robust for Dravet syndrome, where stiripentol added to clobazam and valproic acid reduces seizure frequency and severity in the majority of cases. Small case series have also suggested benefit for malignant migrating partial seizures in infancy, super-refractory status epilepticus, and intractable focal epilepsy, although larger prospective studies are needed in these disorders.

Response to second treatment after initial failed treatment in a multicenter prospective infantile spasms cohort

OBJECTIVE

Infantile spasms (IS) represent a severe epileptic encephalopathy presenting in the first 2 years of life. Recommended first-line therapies (hormonal therapy or vigabatrin) often fail. We evaluated response to second treatment for IS in children in whom the initial therapy failed to produce both clinical remission and electrographic resolution of hypsarhythmia and whether time to treatment was related to outcome.

METHODS

The National Infantile Spasms Consortium established a multicenter, prospective database enrolling infants with new diagnosis of IS. Children were considered nonresponders to first treatment if there was no clinical remission or persistence of hypsarhythmia. Treatment was evaluated as hormonal therapy (adrenocorticotropic hormone [ACTH] or oral corticosteroids), vigabatrin, or "other." Standard treatments (hormonal and vigabatrin) were compared to all other nonstandard treatments. We compared response rates using chi-square tests and multivariable logistic regression models.

RESULTS

One hundred eighteen infants were included from 19 centers. Overall response rate to a second treatment was 37% (n = 44). Children who received standard medications with differing mechanisms for first and second treatment had higher response rates than other sequences (27/49 [55%] vs. 17/69 [25%], p < 0.001). Children receiving first treatment within 4 weeks of IS onset had a higher response rate to second treatment than those initially treated later (36/82 [44%] vs. 8/34 [24%], p = 0.040).

SIGNIFICANCE

Greater than one third of children with IS will respond to a second medication. Choosing a standard medication (ACTH, oral corticosteroids, or vigabatrin) that has a different mechanism of action appears to be more effective. Rapid initial treatment increases the likelihood of response to the second treatment.

Cognitive and neurodevelopmental comorbidities in paediatric epilepsy

Cognitive and behavioural comorbidities are often seen in children with epilepsy, and are more common and severe in refractory epilepsy. These comorbidities are associated with worse quality of life, increased behavioural and language problems and worse social skills, all of which adversely affect long-term psychosocial functioning. To enable early intervention and therapy, children and teens with epilepsy should be periodically screened for cognitive comorbidities. The location of the epileptic focus can, to a certain degree, predict the type(s) of comorbidity; however, the spectrum of disability is often broad, presumably because focal perturbations can cause network dysfunction. Comorbidities often result from underlying structural or functional pathology that has led to seizures. In selected cases, therapy targeting the underlying cause, such as the ketogenic diet for GLUT1 deficiency syndromes, may be remarkably effective in ameliorating both seizures and cognitive concerns. In many cases, however, cognitive impairment persists despite seizure control. In epileptic encephalopathies, frequent seizures and/or interictal epileptiform abnormalities exacerbate neurocognitive dysfunction, owing to synaptic reorganization or impaired neurogenesis, or to other effects on developing neural circuits, and prompt initiation of effective antiepileptic therapy is essential to limit cognitive comorbidities.

Usefulness of repeat review of head magnetic resonance images during presurgical epilepsy conferences

Surgical epilepsy conferences are an important part of the process of determining whether a patient is a candidate for resective epilepsy surgery. At these conferences, repeat review (re-review) of the magnetic resonance images (MRIs) of the patient's head often occurs. This study assessed how often radiologic re-review at a presurgical epilepsy conference resulted in a changed interpretation of the head MRI. Charts were reviewed for 239 patients who had been presented at presurgical epilepsy conferences between 2008 and 2012. Of the 233 patients whose MRIs were re-reviewed, resective surgery was performed in 94 patients (40.3%). Forty-one patients (17.6%) had a previously undiagnosed finding, and 18 of the 41 (43.9%) underwent resective surgery. For 4 of the 41 patients (9.8%) with a previously undiagnosed pertinent finding, re-review detected abnormalities that were not amenable to surgical resection (autoimmunity or significant bilateral pathology).

Routine vs extended outpatient EEG for the detection of interictal epileptiform discharges

OBJECTIVE

To compare the yield of epileptiform abnormalities on 30-minute recordings with those greater than 45 minutes.

METHODS

We performed a prospective observational cross-sectional study of all outpatient routine EEGs comparing the rate of interictal epileptiform discharges (IEDs) and clinical events during the initial 30 minutes (routine) with those occurring in the remaining 30-60 minutes (extended). A relative increase of 10% was considered clinically significant.

RESULTS

EEGs from 1,803 patients were included; overall EEG duration was 59.4 minutes (SD ±6.5). Of 426 patients with IEDs at any time during the EEG, 81 (19.1%, 95% confidence interval 15.6-23) occurred only after the initial 30 minutes. The rate of late IEDs was not associated with age, indication, IED type, or sleep deprivation. Longer recording times also increased event capture rate by approximately 30%.

CONCLUSIONS

The yield of IED and event detection is increased in extended outpatient EEGs compared to 30-minute studies.

Pediatric EEG

Electroencephalography (EEG) is an important part of the evaluation of many disorders in infants and children, including seizures, spells, transient central nervous system (CNS) symptoms, behavioral disorders, altered states of consciousness, and lesions or conditions resulting in a disturbance of cerebral function. As in adults, abnormal EEGs in children can be helpful in diagnosing epileptic vs. non-epileptic spells, determining the degree and extent of disturbance of cerebral function, and identifying underlying etiologies for neurological symptoms. This chapter discusses the normal developmental patterns in preterm infants, term neonates, infants, and children. Knowledge of the normal EEG patterns and how they change with maturation is essential in order to accurately interpret the EEG. Without this understanding, normal patterns may be erroneously thought of as abnormal, or abnormal patterns may be missed, leading to improper diagnosis and treatment of the child.

Response to treatment in a prospective national infantile spasms cohort

OBJECTIVE

Infantile spasms are seizures associated with a severe epileptic encephalopathy presenting in the first 2 years of life, and optimal treatment continues to be debated. This study evaluates early and sustained response to initial treatments and addresses both clinical remission and electrographic resolution of hypsarrhythmia. Secondarily, it assesses whether response to treatment differs by etiology or developmental status.

METHODS

The National Infantile Spasms Consortium established a multicenter, prospective database enrolling infants with new diagnosis of infantile spasms. Children were considered responders if there was clinical remission and resolution of hypsarrhythmia that was sustained at 3 months after first treatment initiation. Standard treatments of adrenocorticotropic hormone (ACTH), oral corticosteroids, and vigabatrin were considered individually, and all other nonstandard therapies were analyzed collectively. Developmental status and etiology were assessed. We compared response rates by treatment group using chi-square tests and multivariate logistic regression models.

RESULTS

Two hundred thirty infants were enrolled from 22 centers. Overall, 46% of children receiving standard therapy responded, compared to only 9% who responded to nonstandard therapy (p < 0.001). Fifty-five percent of infants receiving ACTH as initial treatment responded, compared to 39% for oral corticosteroids, 36% for vigabatrin, and 9% for other (p < 0.001). Neither etiology nor development significantly modified the response pattern by treatment group.

INTERPRETATION

Response rate varies by treatment choice. Standard therapies should be considered as initial treatment for infantile spasms, including those with impaired development or known structural or genetic/metabolic etiology. ACTH appeared to be more effective than other standard therapies.

Repeat resective surgery in complex pediatric refractory epilepsy: lessons learned

OBJECT Resection can sometimes offer the best chance of meaningful seizure reduction in children with medically intractable epilepsy. However, when surgery fails to achieve the desired outcome, reoperation may be an option. The authors sought to investigate outcomes following resective reoperation in pediatric patients with refractory epilepsy, excluding tumoral epilepsies. Differences in preoperative workup between surgeries are analyzed to identify factors influencing outcomes and complications in this complex group. METHODS Medical records were reviewed for all pediatric patients undergoing a repeat resective surgery for refractory epilepsy at the authors' institution between 2005 and 2012. Tumor and vascular etiologies were excluded. Preoperative evaluation and outcomes were analyzed for each surgery and compared. RESULTS Ten patients met all inclusion criteria. The median age at seizure onset was 4.5 months. Preoperative MRI revealed no lesion in 30%. Nonspecific gliosis and cortical dysplasia were the most common pathologies. The majority of preoperative workups included MRI, video-electroencephalography (EEG), and SISCOM. Intracranial EEG was performed for 60% for the first presurgical evaluation and 70% for the second evaluation. The goal of surgery was palliative in 4 patients with widespread cortical dysplasia. The final Engel outcome was Class I in 50%. The rate of favorable outcome (Engel Class I-II) was 70%. The complication rate for the initial surgery was 10%. However, the rate increased to 50% with the second surgery, and 3 of these 5 complications were pseudomeningoceles requiring shunt placement (2 of the 3 patients underwent hemispherotomy). CONCLUSIONS Resective reoperation for pediatric refractory epilepsy has a high rate of favorable outcome and should be considered in appropriate candidates, even as a palliative measure. Intracranial EEG monitoring should be considered on initial workup in cases where the results of imaging or EEG studies are ambiguous or conflicting. Epilepsy secondary to cortical dysplasia, especially if the dysplasia is not seen clearly on MRI, can be difficult to cure surgically. Therefore, in these cases, as large a resection as can be safely accomplished should be done, particularly when the goal is palliative. The rate of complications, particularly pseudomeningocele ultimately requiring shunt placement, is much higher following reoperation, and patients should be counseled accordingly.

Yield and Predictors of Epilepsy Surgery Candidacy in Children Admitted for Surgical Evaluation

OBJECTIVE

The aim of this study was to identify preadmission variables that are prognostic of epilepsy surgical candidacy for children admitted into an epilepsy-monitoring unit.

METHODS

This study is a retrospective review of patients 0-18 years who were admitted into the pediatric epilepsy-monitoring unit at Mayo Clinic between November 2010 and December 2013 to assess for surgery candidacy for medically intractable epilepsy. Demographic data, epilepsy details, treatments, electroencephalograph and imaging results, and the consensus notes of the epilepsy surgery conferences were collected.

RESULTS

One hundred and forty eight children underwent inpatient, prolonged video-electroencephalograph monitoring for presurgical evaluation, of which 136 had their typical events recorded. Five recommended for callosotomy alone were excluded and 131 composed the study group. Of these 131, the epilepsy surgery conference consensus deemed that 69 were surgical candidates, of which 45 (65%) underwent resective surgery. Chi-square analysis found seven preadmission predictors of surgical candidacy: single semiology at seizure onset (P < 0.001), structural etiology (P < 0.001), one or more interictal foci all in the same hemisphere (P < 0.004), focal background electroencephalograph slowing (P < 0.001), focal or hemispheric abnormality on magnetic resonance imaging (P < 0.001), male sex (P = 0.02), and normal development (P = 0.04).

CONCLUSIONS

The presence of fewer than four predictors was suggestive of low likelihood of candidacy (<31%), whereas if more than four factors were present, 91% were found to be surgical candidates. These findings facilitate clinical decision-making for providers in a cost-effective manner and provide realistic expectations for families.

Utility of an immunotherapy trial in evaluating patients with presumed autoimmune epilepsy

OBJECTIVE

To evaluate a trial of immunotherapy as an aid to diagnosis in suspected autoimmune epilepsy.

METHOD

We reviewed the charts of 110 patients seen at our autoimmune neurology clinic with seizures as a chief complaint. Twenty-nine patients met the following inclusion criteria: (1) autoimmune epilepsy suspected based on the presence of ≥ 1 neural autoantibody (n = 23), personal or family history or physical stigmata of autoimmunity, and frequent or medically intractable seizures; and (2) initiated a 6- to 12-week trial of IV methylprednisolone (IVMP), IV immune globulin (IVIg), or both. Patients were defined as responders if there was a 50% or greater reduction in seizure frequency.

RESULTS

Eighteen patients (62%) responded, of whom 10 (34%) became seizure-free; 52% improved with the first agent. Of those receiving a second agent after not responding to the first, 43% improved. A favorable response correlated with shorter interval between symptom onset and treatment initiation (median 9.5 vs 22 months; p = 0.048). Responders included 14/16 (87.5%) patients with antibodies to plasma membrane antigens, 2/6 (33%) patients seropositive for glutamic acid decarboxylase 65 antibodies, and 2/6 (33%) patients without detectable antibodies. Of 13 responders followed for more than 6 months after initiating long-term oral immunosuppression, response was sustained in 11 (85%).

CONCLUSIONS

These retrospective findings justify consideration of a trial of immunotherapy in patients with suspected autoimmune epilepsy.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that in patients with suspected autoimmune epilepsy, IVMP, IVIg, or both improve seizure control.

Chronic subthreshold subdural cortical stimulation for the treatment of focal epilepsy originating from eloquent cortex

Medically refractory epilepsy remains a major medical problem worldwide. Although some patients are eligible for surgical resection of seizure foci, a proportion of patients are ineligible for a variety of reasons. One such reason is that the foci reside in eloquent cortex of the brain and therefore resection would result in significant morbidity. This retrospective study reports our experience with a novel neurostimulation technique for the treatment of these patients. We identified three patients who were ineligible for surgical resection of the intracranially identified seizure focus because it resided in eloquent cortex, who underwent therapeutic trial of focal cortical stimulation delivered through the subdural monitoring grid. All three patients had a significant reduction in seizures, and two went on to permanent implantation, which resulted in long-term reduction in seizure frequency. In conclusion, this small case report provides some evidence of proof of concept of the role of targeted continuous neocortical neurostimulation in the treatment of medically refractory focal epilepsy, and provides support for ongoing investigations into this treatment modality.

What predicts enduring intractability in children who appear medically intractable in the first 2 years after diagnosis?

PURPOSE

In a population-based retrospective cohort of children with newly diagnosed epilepsy, to determine (1) what proportion meet criteria for early medical intractability, and (2) predictors of enduring intractability.

METHODS

Children with newly diagnosed epilepsy between 1980 and 2009 while resident in Olmsted County, MN, and followed >36 months, were stratified into groups based on both early medical intractability ("apparent" medical intractability in the first 2 years) and enduring intractability (persisting intractability at final follow-up or having undergone surgery for intractable epilepsy), and variables predicting these outcomes were evaluated.

KEY FINDINGS

Three hundred eighty-one children were included, representing 81% of our cohort with newly diagnosed epilepsy. Seventy five (19.7%) had early medical intractability, and predictors of this outcome on multivariable analysis were neuroimaging abnormality (risk ratio, 2.70; p = 0.0004), abnormal neurologic examination at diagnosis (risk ratio, 1.87; p = 0.015), and mode of onset (association was significant for focal vs. generalized onset [risk ratio, 0.25; p < 0.0001] but not unknown vs. generalized onset [p = 0.065]). After a median follow-up of 11.7 years, 49% remained intractable, 8% had rare seizures (≤ every 6 months), and the remainder were seizure-free. The only factor predicting enduring intractability on multivariable analysis was neuroimaging abnormality (risk ratio, 7.0; p = 0.0006).

SIGNIFICANCE

Although a significant minority of children with early medical intractability ultimately achieved seizure control without surgery, those with an abnormal imaging study did poorly. For this subgroup, early surgical intervention is strongly advised to limit comorbidities of ongoing, intractable seizures. Conversely, a cautious approach is suggested for those with normal imaging, as most will remit with time.

Pediatric epilepsy syndromes

Epilepsy syndromes denote specific constellations of clinical seizure type(s), EEG findings, and other characteristic clinical features. Most syndromes recognized in epilepsy are genetic and developmental disorders that begin in the pediatric years. Epilepsy syndromes are divided into idiopathic (primary) types, in which the presumed etiology is genetic, versus symptomatic (secondary) types, in which there is either an underlying etiology that is known or presumed based on other evidence of brain dysfunction. Epilepsies are also classified by those with generalized seizures and those with localization-related seizures. Identification of a specific syndrome is important to define the best treatment and accurately prognosticate long-term outcome for children with epilepsy. In this chapter, clinical and electrographic features as well as inheritance patterns of common pediatric epilepsy syndromes are discussed.

Epilepsy-related mortality is low in children: a 30-year population-based study in Olmsted County, MN

PURPOSE

Epilepsy is a common childhood neurologic disorder, affecting 0.5-1% of children. Increased mortality occurs due to progression of underlying disease, seizure-related accidents, suicide, status epilepticus, aspiration during seizures, and sudden unexplained death in epilepsy (SUDEP). Previous studies show mortality rates of 2.7-6.9 per 1,000 person-years. Potential risk factors include poor seizure control, intractable epilepsy, status epilepticus, tonic-clonic seizures, mental retardation, and remote symptomatic cause of epilepsy. Few population-based studies of mortality and SUDEP in childhood-onset epilepsy have been published. The purpose of this study is to report mortality and SUDEP from a 30-year population-based cohort of children with epilepsy.

METHODS

The Medical Diagnostic Index of the Rochester Epidemiology Project was searched for all codes related to seizure and convulsion in children living in Olmsted County, Minnesota and of ages birth through 17 years from 1980 through 2009. The medical records of these children were reviewed to identify all those with new-onset epilepsy, and to abstract other baseline and follow-up information. Potential risk factors including seizure type, epilepsy syndrome, history of status epilepticus, the presence and severity of neurologic impairment, and epilepsy outcome was reviewed. Epilepsy outcome was characterized by seizure frequency, number of antiseizure medications (antiepileptic drugs, AEDs) used, and number of AEDs failed due to lack of efficacy, and epilepsy intractability at 1 year and 2, 3, 5, 10, 15, and 20 years after epilepsy onset. We followed all children through their most recent visit to determine vital status, cause of death, and whether autopsy was performed.

KEY FINDINGS

From 1980 to 2009, there were 467 children age birth through 17 years diagnosed with epilepsy while residents of Olmsted County, Minnesota, and who had follow-up beyond the time of epilepsy diagnosis. Children were followed for a median of 7.87 years after the time of diagnosis (range 0.04-29.49 years) for a total of 4558.5 person-years. Sixteen (3.4%) of the children died, or 3.51 deaths per 1,000 person-years. Two deaths were epilepsy related (12.5%) for a rate of 0.44 per 1,000 person-years. One of these children died of probable SUDEP and one died of aspiration during a seizure. The remaining 14 deaths (87.5%) were caused by other complications of underlying disease. Several risk factors for mortality were found, including abnormal cognition, abnormal neurologic examination, structural/metabolic etiology for epilepsy, and poorly controlled epilepsy.

SIGNIFICANCE

Although mortality in children with epilepsy was higher than what would be expected in the general pediatric population, death occurred significantly more in children with neurologic impairment and poorly controlled epilepsy. Epilepsy-related death, including SUDEP, was rare and mortality due to epilepsy alone was similar to the expected mortality in the general population (observed deaths = 2, expected deaths = 1.77; standardized mortality ratio 1.13, 95% confidence interval 0.19-3.73, p = 0.86). By contrast, most children died of complications of the underlying neurologic disease or unrelated disease rather than the epilepsy.

Autoimmune epilepsy: clinical characteristics and response to immunotherapy

OBJECTIVE

To describe clinical characteristics and immunotherapy responses in patients with autoimmune epilepsy.

DESIGN

Observational, retrospective case series.

SETTING

Mayo Clinic Health System.

PATIENTS

Thirty-two patients with an exclusive (n=11) or predominant (n=21) seizure presentation in whom an autoimmune etiology was suspected (on the basis of neural autoantibody [91%], inflammatory cerebrospinal fluid [31%], or magnetic resonance imaging suggesting inflammation [63%]) were studied. All had partial seizures: 81% had failed treatment with 2 or more antiepileptic drugs and had daily seizures and 38% had seizure semiologies that were multifocal or changed with time. Head magnetic resonance imaging was normal in 15 (47%) at onset. Electroencephalogram abnormalities included interictal epileptiform discharges in 20; electrographic seizures in 15; and focal slowing in 13. Neural autoantibodies included voltage-gated potassium channel complex in 56% (leucine-rich, glioma-inactivated 1 specific, 14; contactin-associated proteinlike 2 specific, 1); glutamic acid decarboxylase 65 in 22%; collapsin response- mediator protein 5 in 6%; and Ma2, N-methyl-D-aspartate receptor, and ganglionic acetylcholine receptor in 1 patient each.

INTERVENTION

Immunotherapy with intravenous methylprednisolone; intravenous immune globulin; and combinations of intravenous methylprednisolone, intravenous immune globulin, plasmapheresis, or cyclophosphamide.

MAIN OUTCOME MEASURE

Seizure frequency.

RESULTS

After a median interval of 17 months (range, 3-72 months), 22 of 27 (81%) reported improvement postimmunotherapy; 18 were seizure free. The median time from seizure onset to initiating immunotherapy was 4 months for responders and 22 months for nonresponders (P<.05). All voltage-gated potassium channel complex antibody-positive patients reported initial or lasting benefit (P<.05). One voltage-gated potassium channel complex antibody-positive patient was seizure free after thyroid cancer resection; another responded to antiepileptic drug change alone.

CONCLUSION

When clinical and serological clues suggest an autoimmune basis for medically intractable epilepsy, early-initiated immunotherapy may improve seizure outcome.

Historic, clinical, and prognostic features of epileptic encephalopathies caused by CDKL5 mutations

Mutations within the X-linked cyclin-dependent kinase-like 5 (CDKL5) gene are important causes of early-onset epileptic encephalopathies. We sought to determine the historic, clinical, and prognostic features of epilepsy secondary to CDKL5 mutations. We performed retrospective chart reviews of children at our institution with epilepsy and CDKL5 mutations. Six children were identified. One manifested a deletion in exons 10-15 of the CDKL5 gene, another manifested a single base-pair duplication in exon 3, and the rest manifested base-pair exchanges. The mean age of seizure onset was 1.8 months (range, 1-3 months). Although the majority (4/6, 67%) presented with partial-onset seizures, all children developed infantile spasms. All children demonstrated developmental delay and visual impairment. Although such mutations are X-linked, two children were boys. They did not present with more severe phenotypes than their female counterparts. Despite trials of antiepileptic drugs (mean, 5; range, 3-7), steroids/adrenocorticotropic hormone (4/6; 67%), and the ketogenic diet (6/6; 100%), all children manifested refractory seizures at last follow-up. Although no treatment eliminated seizures, topiramate, vigabatrin, and the ketogenic diet were most helpful at reducing seizure frequency.

Incidence and classification of new-onset epilepsy and epilepsy syndromes in children in Olmsted County, Minnesota from 1980 to 2004: a population-based study

PURPOSE

To determine the incidence and classification of new-onset epilepsy, as well as the distribution of epilepsy syndromes in a population-based group of children, using the newly proposed Report of the ILAE Commission on Classification and Terminology 2005-2009.

METHODS

We identified all children residing in Olmsted County, MN, 1 month through 17 years with newly diagnosed epilepsy from 1980 to 2004. For each patient, epilepsy was classified into mode of onset, etiology, and syndrome or constellation (if present). Incidence rates were calculated overall and also separately for categories of mode of onset and etiology.

RESULTS

The adjusted incidence rate of new-onset epilepsy in children was 44.5 cases per 100,000 persons per year. Incidence rates were highest in the first year of life and diminished with age. Mode of onset was focal in 68%, generalized/bilateral in 23%, spasms in 3% and unknown in 5%. Approximately half of children had an unknown etiology for their epilepsy, and of the remainder, 78 (22%) were genetic and 101 (28%) were structural/metabolic. A specific epilepsy syndrome could be defined at initial diagnosis in 99/359 (28%) children, but only 9/359 (3%) had a defined constellation.

CONCLUSION

Nearly half of childhood epilepsy is of "unknown" etiology. While a small proportion of this group met criteria for a known epilepsy syndrome, 41% of all childhood epilepsy is of "unknown" cause with no clear syndrome identified. Further work is needed to define more specific etiologies for this group.

Neuronal voltage-gated potassium channel complex autoimmunity in children

Autoimmunity targeting voltage-gated potassium channel complexes have not been systematically documented in children. Identified in the Neuroimmunology Laboratory records of Mayo Clinic were 12 seropositive children, 7 among 252 Mayo Clinic pediatric patients tested on a service basis for serologic evidence of neurologic autoimmunity (June 2008-April 2010), 4 during the assay's preimplementation validation (before June 2008) and 1 non-Mayo patient with available clinical information. Neurologic manifestations were subacute and multifocal. Three had global developmental regression, 6 movement disorders, 4 dysarthria, 3 seizures, 1 Satoyoshi syndrome, 1 painful red feet, 2 insomnia, 2 gastrointestinal dysmotility, and 2 small fiber neuropathy. Neoplasia was found in 1 child. Treating physicians recorded improvement in all 7 children who received immunotherapy. Neurologic symptom relapse occurred in 3 of 6 children after ceasing immunotherapy. These findings highlight a diverse clinical spectrum of neuronal potassium channel complex autoimmunity in children, and they illustrate benefit from early initiated immunotherapy, with a tendency to relapse when therapy ceases. Diagnosis is generally delayed in the process of eliminating neurodegenerative causes. Currently 2.7% of pediatric sera evaluated for neurologic autoimmunity are positive for neuronal potassium channel complex-reactive immunoglobulin G. The frequency and full spectrum of neurologic accompaniments remains to be determined.

A population-based study of long-term outcomes of cryptogenic focal epilepsy in childhood: cryptogenic epilepsy is probably not symptomatic epilepsy

PURPOSE

To compare long-term outcome in a population-based group of children with cryptogenic versus symptomatic focal epilepsy diagnosed from 1980 to 2004 and to define the course of epilepsy in the cryptogenic group.

METHODS

We identified all children residing in Olmsted County, MN, 1 month through 17 years, with newly diagnosed, nonidiopathic focal epilepsy from 1980 to 2004. Children with idiopathic partial epilepsy syndromes were excluded. Medical records were reviewed to determine etiology, results of imaging and EEG studies, treatments used, and long-term outcome. Children were defined as having symptomatic epilepsy if they had a known genetic or structural/metabolic etiology, and as cryptogenic if they did not.

KEY FINDINGS

Of 359 children with newly diagnosed epilepsy, 215 (60%) had nonidiopathic focal epilepsy. Of these, 206 (96%) were followed for > 12 months. Ninety-five children (46%) were classified as symptomatic. Median follow-up from diagnosis was similar in both groups, being 157 months (25%, 75%: 89, 233) in the cryptogenic group versus 134 months (25%, 75%: 78, 220) in the symptomatic group (p = 0.26). Of 111 cryptogenic cases, 66% had normal cognition. Long-term outcome was significantly better in those with cryptogenic versus symptomatic etiology (intractable epilepsy at last follow-up, 7% vs. 40%, p < 0.001; seizure freedom at last follow-up, 81% vs. 55%, p < 0.001). Of those who achieved seizure freedom at final follow-up, 68% of the cryptogenic group versus only 46% of the symptomatic group were off antiepileptic medications (p = 0.01). One-third of the cryptogenic group had a remarkably benign disorder, with no seizures seen after initiation of medication, or in those who were untreated, after the second afebrile seizure. A further 5% had seizures within the first year but remained seizure-free thereafter. With the exception of perinatal complications, which predicted against seizure remission, no other factors were found to significantly predict outcome in the cryptogenic group.

SIGNIFICANCE

More than half of childhood nonidiopathic localization-related epilepsy is cryptogenic. This group has a significantly better long-term outcome than those with a symptomatic etiology, and should be distinguished from it.

EEG and neuroimaging studies in young children having epilepsy surgery

The aim of this study was to evaluate the yield of electroencephalography and structural and functional neuroimaging in children having resective epilepsy surgery before 5 years of age. Charts of all 28 children (54% male) having resective surgery before 60 months of age at the Mayo Clinic between January 2002 and June 2009 were reviewed. Mean age at seizure onset was 9.6 months (S.D. 12.7); mean age at surgery was 28.8 months (S.D. 17.7). Sixteen children (57%) had partial-onset seizures, 8 (29%) had partial-onset seizures and spasms, and 4 (14%) had spasms alone. Initial surgery type was hemispherectomy in 6 cases, multilobar resection in 8, temporal in 7, and extratemporal in 7. Only 10 of the 25 children (40%) with recorded seizures preoperatively had a well-localized, single ictal focus. Ictal discharge was generalized in 8/25 cases (32%), both generalized and focal in 1 case (4%), hemispheric in 4 cases (16%), and absent in 1 case (4%). Findings from magnetic resonance imaging were abnormal in 27 cases, and revealed focal pathology in 20. Surgical outcome was favorable, with 18 of the 27 survivors (67%) being free, or nearly free, of disabling seizures. In summary, electroencephalography frequently failed to indicate a single ictal focus in young children having epilepsy surgery. In contrast, magnetic resonance imaging was more helpful, revealing focal abnormalities in 74% of patients.

Testicular abnormalities in male rats after lactational exposure to nonylphenols

Lactational exposure of male rat pups to nonylphenols (NPs) decreased the size of their testes and male accessory glands. At 31 d of age, NP-treatment of male rats resulted in less cellular differentiation of the seminiferous tubules (STs) and increased intertubular space compared to controls. At maturity, NP-treated males showed varying degrees of abnormalities in the affected testes. In the moderately affected ones, about 20-30% of their STs had poorly differentiated germinal elements. Cell lineage was less organized. In extreme cases, all STs of the affected testis failed to differentiate into germinal elements. These abnormalities in germinal element differentiation might be the primary cause for a number of the NP-treated males having a lower epididymal sperm count and a lower percentage of motile sperm compared to age-matched control males. Zymogram analysis of testis homogenates by sodium dodecyl sulfate gelatin gels revealed two major forms (64-66 kDa and 50-52 kDa) of gelatinases. Only the 50-52-kDa form was greatly reduced or absent in the affected testis. Lactational exposure of male pups to NPs thus leads to various testicular abnormalities including lack of differentiation of STs, lowering of sperm count, and reduction in the percentage of motile sperm and modulation of a specific form of testicular proteinases.