Caregiver-reported outcomes with real-world use of cannabidiol in Lennox-Gastaut syndrome and Dravet syndrome from the BECOME survey.

PURPOSE: Plant-derived highly purified cannabidiol (CBD) reduced the frequency of seizures associated with Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) and improved the overall condition of patients in placebo-controlled phase 3 clinical trials. Anecdotal reports also suggest a positive effect on nonseizure outcomes. In this study, we aimed to identify, through a caregiver survey which nonseizure outcomes were most likely to change in these patients. METHODS: The BEhavior, COgnition, and More with Epidiolex® (BECOME) was a 20-minute, cross-sectional, online survey that was developed with extensive input from caregivers, healthcare professionals, and epilepsy researchers, and was based on questions from validated measures and previously published caregiver reports. US-based caregivers (from Jazz Pharmaceuticals patient/caregiver database) of people with LGS or DS who were treated with CBD (Epidiolex®, 100 mg/mL oral solution) for ≥3 months were asked to compare the past month to the period before CBD initiation and rate their impression of changes using symmetrical Likert scales. RESULTS: A total of 498 caregivers (97% parents) of patients with LGS (80%) or DS (20%) completed the survey. Mean (range) age of patients was 16 (1-73) years, and 52% were male. Patients were taking a median CBD dose of 14 mg/kg/d and median 4 concomitant antiseizure medications. A large proportion of respondents reported improvements in ≥1 survey question for all nonseizure-related domains: alertness, cognition, and executive function (85%); emotional functioning (82%); language and communication (79% in nonverbal patients and 74% in verbal); activities of daily living (51%); sleep (51%); and physical functioning (46%). Respondents reported improvements in seizure-related domains, including overall seizure frequency (85%), overall seizure severity (76%), seizure-free days per week for ≥1 seizure type (67%), and seizure freedom during the past month (16%). The majority of respondents who reported reduction in seizure frequency also reported improvements in nonseizure outcomes domains (51-80%). However, improvements in nonseizure outcomes (18-56%) were also reported in patients who either had no change or worsening of seizure frequency. CONCLUSIONS: This survey characterized and quantified caregiver impression of changes in the seizure and nonseizure outcomes in patients taking add-on CBD treatment. Overall, 93% of caregivers reported planning to continue CBD treatment, primarily because of reduced seizure burden but also because of improvements in nonseizure-related outcomes. Despite the limitations that are associated with a retrospective survey-based study design, these results support further evaluation of the effect of CBD treatment on nonseizure outcomes among patients with LGS or DS.

Caregivers' Perspectives on the Impact of Cannabidiol (CBD) Treatment for Dravet and Lennox-Gastaut Syndromes: A Multinational Qualitative Study.

OBJECTIVE: To increase understanding of the impact of cannabidiol (CBD) on outcomes beyond seizure control among individuals with Dravet syndrome or Lennox-Gastaut syndrome. METHODS: Qualitative interviews were conducted with caregivers of individuals with Dravet syndrome or Lennox-Gastaut syndrome treated with plant-derived, highly purified CBD medicine (Epidiolex in the USA; Epidyolex in Europe; 100 mg/mL oral solution). Symptoms and impacts of Dravet syndrome and Lennox-Gastaut syndrome on individuals were explored, as were the effects of CBD. Data were analyzed using thematic analysis. RESULTS: Twenty-one caregivers of individuals with Dravet syndrome (n = 14) and Lennox-Gastaut syndrome (n = 7) aged 4-22 years participated. Health-related quality of life improvements associated with CBD included cognitive function, communication, behavior, mobility, and participation in daily activities. Seizure frequency reduction was commonly reported (n = 12), resulting in caregivers having greater freedom and family life being less disrupted. Adverse events were reported by 10 caregivers. CONCLUSION: In addition to reduced seizure frequency, CBD may have a wide range of beneficial effects beyond seizure control that warrant further investigation.

Tonic Seizures in a Patient With Lennox-Gastaut Syndrome Manifest as "Icicles" Rather Than "Flames" on Quantitative EEG Analysis.

SUMMARY: Quantitative analysis of continuous electroencephalography (QEEG) is increasingly being used to augment seizure detection in critically ill patients. Typically, seizures manifest on QEEG as abrupt increases in power and frequency, a visual pattern often called "flames." Here, we present a case of a 16-year-old patient with intractable Lennox-Gastaut syndrome secondary to a pathogenic variant in the SCN2A gene who had tonic seizures that manifest as abrupt decreases in power on QEEG, a visual pattern we term "icicles." Recognition of QEEG patterns representative of different seizure types is important as QEEG use becomes more widespread including in pediatric populations.

A Case Report for Using Methylprednisolone for Severe ARDS Caused by SARS-CoV-2 Delta Variant in a Pediatric Patient With Lennox-Gastaut Syndrome.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in the coronavirus disease 2019 (COVID-19) pandemic. COVID-19 can result in fatal comorbidities, including acute respiratory distress syndrome (ARDS). Several reports suggest that children have milder illness, though severe cases have still been reported. We report a 9-year-old boy with ARDS caused by the SARS-CoV-2 delta (B.1.617.2) variant. He was admitted to our hospital and carefully observed due to underlying Lennox-Gastaut syndrome. He developed intractable seizures with a high fever. Although the seizures were controlled, his respiratory condition deteriorated to severe ARDS. High-dose methylprednisolone was administered with high positive end-expiratory pressure and low tidal volume. After ARDS treatment, oxygenation improved sufficiently to permit extubation. This case suggests that close observation is required in pediatric patients with neurologic comorbidities because of an increased risk for severe COVID-19.

Endoscopic Total Corpus Callosotomy and Pan Commissurotomy for Lennox-Gastaut Syndrome.

Background: Corpus callosotomy (CC) is a major disconnection procedure that functionally isolates the cerebral hemispheres, thereby interrupting the spread of epileptic activity from one hemisphere to the other. It is extremely useful in children suffering from non-localized drug refractory epilepsy, especially drop attacks. The technique has evolved from microscopic to minimally invasive endoscopic surgery. The extent of callosotomy also varies based on the institutional practices ranging from anterior 1/3rd to total corpus callosotomies (TCC). The performance of TCC in conjunction with anterior, posterior, and hippocampal commissurotomies was described for the first time by the senior author from our institution. Objective: To describe the technique of performing endoscopic total corpus callosotomy, and pan commissurotomy using the interhemispheric corridor. Methods: A seven-year-old right-handed male child with seizure onset at the age of six months presented with three types of semiologies consisting of myoclonic jerks, frequent head drops and tonic posturing involving right upper and lower limbs with secondary generalization. Results: Video electroencephalography (VEEG) revealed diffuse slowing of the background, and slow spike and wave pattern. Generalized paroxysmal fast activity (GPFA) was noted in the VEEG, suggestive of LGS. MRI brain revealed bilateral parieto-occipital gliosis and gross brain atrophy. Ictal SPECT localized to left temporo-occipital area, while magnetoencephalography revealed bilateral temporal localization. Patient underwent TCC with pancommissurotomy. The patient was seizure-free (ILAE Class 3) at one-year follow up with no drop attacks, and significant reduction noted in other seizure types. Conclusion: Endoscopic corpus callosotomy and pan commissurotomy using the interhemispheric corridor is an elegant and minimally invasive technique best suited for appropriately selected children with refractory epilepsy.

Children With Trisomy 21 and Lennox-Gastaut Syndrome With Predominant Myoclonic Seizures.

INTRODUCTION: Lennox-Gastaut syndrome is a severe form of pediatric epilepsy that is classically defined by a triad of drug-resistant seizures, including atonic, tonic, and atypical absence seizures; slow spike-and-wave discharges and paroxysmal fast activity on electroencephalography (EEG); and cognitive and behavioral dysfunction. In the vast majority, Lennox-Gastaut syndrome develops in patients with an identified etiology, including genetic or structural brain abnormalities. Long-term prognosis is generally poor with progressive intellectual deterioration and persistent seizures. At present, there are few reported cases of Lennox-Gastaut syndrome and trisomy 21 in the literature. To further delineate the spectrum of epilepsy in trisomy 21, we reviewed children with trisomy 21 and Lennox-Gastaut syndrome at one center over 28 years. METHODS: This is a retrospective case series. At our institution, all EEG results are entered into a database, which was queried for patients with trisomy 21 from 1992 to 2019. Pertinent electroclinical data was obtained from medical records. RESULTS: Of 63 patients with trisomy 21 and epilepsy, 6 (10%) had Lennox-Gastaut syndrome and were included in the study. Four of the 6 patients were male and 5 of 6 had neuroimaging, which was normal. Follow-up ranged from 3 to 20 years. Notably, 5 of 6 had predominant myoclonic seizures throughout the course of their epilepsy, associated with generalized spike-wave discharges, <100 milliseconds. CONCLUSION: We observed myoclonic seizures to be a predominant seizure type in patients with trisomy 21, suggestive that trisomy 21 patients may have a unique pattern of Lennox-Gastaut syndrome.

Hypercalcemia in Children Using the Ketogenic Diet: A Multicenter Study.

CONTEXT: The ketogenic diet is associated with progressive skeletal demineralization, hypercalciuria, and nephrolithiasis. Acute hypercalcemia has been described as a newly recognized complication of this treatment. OBJECTIVE: To describe the clinical characteristics of acute hypercalcemia in children on the ketogenic diet through analysis of the presentation, response to treatment, and natural history in a large cohort of patients. DESIGN: A multicenter case series was performed including children who developed acute hypercalcemia while treated with the ketogenic diet. Information on clinical presentation, treatment, and course of this complication was collated centrally. RESULTS: There were 14 patients (median (range) age 6.3 (0.9 to 18) years) who developed hypercalcemia 2.1 (range, 0.2-12) years after starting the ketogenic diet. All had low levels of parathyroid hormone and levels of 1,25-dihydroxyvitamin D were low in all except one. Seven (50%) had impaired renal function at presentation. All except the 2 oldest had low alkaline phosphatase levels for age. Once normocalcemia was achieved, hypercalcemia recurred in only 2 of these patients over observation of up to 9.8 years. One patient discontinued the ketogenic diet prior to achieving normocalcemia while 4 more stopped the diet during follow-up after resolution of hypercalcemia. CONCLUSIONS: Ketotic hypercalcemia can occur years after starting the ketogenic diet, especially in the setting of renal impairment. The mechanism is unknown but appears to be due to reduced osteoblast activity and impaired bone formation. We recommend close attention to optimizing bone health in these children, and screening for the development of ketotic hypercalcemia.

Completion Corpus Callosotomy with Stereotactic Radiosurgery for Drug-Resistant, Intractable Epilepsy.

BACKGROUND: Stereotactic radiosurgery (SRS) offers a noninvasive technique for division of the corpus callosum, which can confer improved seizure control to patients suffering from frequent atonic seizures due to rapid interhemispheric generalization. This noninvasive approach is well-suited for use in a palliative intervention for improved seizure control in this patient population. To our knowledge, this is the first report of radiosurgical completion corpus callosotomy in an adult in the United States. CASE DESCRIPTION: A 20-year-old ambidextrous nonverbal man with a history of refractory generalized epilepsy status post open anterior corpus callosotomy at age 10 years, Lennox-Gastaut syndrome, and autism presented after 2 years of incremental, progressive deterioration in seizure control and behavior including 1 year. The family decided to pursue SRS corpus callosotomy. Under general anesthesia, a volume of interest encompassing a full midsagittal plane of the corpus callosum was defined to deliver 60 Gy to the 50% isodose line fully encompassing the target. Gamma Knife was used with 2 isocenters at 90° and 1 at 110° and isodose lines of 60, 20, and 12 Gy. Treatment was carried out without difficulty or complications while the patient remained under close monitoring. The patient was discharged the next day with a 2-week taper of dexamethasone. CONCLUSIONS: Eight months postradiosurgical corpus callosotomy, the patient is free of atonic seizures and is ambulatory. In carefully selected cases and with protective radiosurgical planning, SRS for completion corpus callosotomy represents an effective option for refractory seizure control.

Electroclinical pattern in the transition from West to Lennox-Gastaut syndrome.

AIM: The aim of this study was to analyze electroclinical features of a group of patients with West syndrome (WS) who subsequently developed Lennox-Gastaut syndrome (LGS) during the transition between both syndromes. METHODS: A retrospective and descriptive study was conducted of a series of patients diagnosed with WS who developed LGS seen at Hospital de Pediatría Prof. Dr. JP Garrahan between January 2012 and January 2019. The medical charts of 170 patients with WS were analyzed. In 63 (37 %) of the children WS evolved to LGS. RESULTS: During the transition from WS to LGS four well-defined electroclinical patterns were recognized. The first corresponded to a group of patients with multiple seizure types, including epileptic spasms associated with multifocal paroxysms; the electroclinical pattern in second group showed mainly focal seizures associated with focal discharges in the EEG; the third group showed predominance of epileptic spasms and myoclonic seizures associated with diffuse spike-and-wave and polyspike-and-wave paroxysms; and the remaining group was characterized by a mixed electroclinical pattern including features of the other three groups. All patients had a neuropsychological deficit. Worsening of cognition and behavior was observed during the transition period in 11, 8, and 5 patients of groups 1, 3, and 4, respectively. CONCLUSION: Our study of the transition period from WS to LGS allowed us to recognize four well-defined electroclinical patterns. The early recognition of the different patterns could, in the future, support a more precocious prognostic evaluation.

Centromedian thalamic responsive neurostimulation for Lennox-Gastaut epilepsy and autism.

The RNS System is not approved in patients under 18, although a critical need for novel treatment modalities in this vulnerable population persist. We present two pediatric patients with drug-resistant epilepsy secondary to Lennox-Gastaut Syndrome (LGS) and autism spectrum disorder (ASD) treated with the RNS System. Both patients have experienced 75-99% clinical seizure reductions in >1 year of follow-up. We illustrate that children with diffuse onset, multifocal epilepsy, including frontal and thalamic circuits thought to exist in the generation of LGS seizures, can be treated with responsive neurostimulation safely and effectively, targeting thalamic networks, and avoiding palliative disconnections and resections.

Cannabidiol efficacy independent of clobazam: Meta-analysis of four randomized controlled trials.

OBJECTIVE: The efficacy of cannabidiol (CBD) with and without concomitant clobazam (CLB) was evaluated in stratified analyses of four large randomized controlled trials, two in Lennox-Gastaut syndrome, and two in Dravet syndrome. METHODS: Each trial of CBD (Epidiolex® in the US; Epidyolex® in the EU; 10 and 20 mg/kg/day) was evaluated by CLB use. The treatment ratio was analyzed using negative binomial regression for changes in seizure frequency and logistic regression for the 50% responder rate, where the principle analysis combined both indications and CBD doses in a stratified meta-analysis. Pharmacokinetic data were examined for an exposure/response relationship based on CLB presence/absence. Safety data were analyzed using descriptive statistics. RESULTS: The meta-analysis favored CBD vs. placebo regardless of CLB use. The treatment ratio (95% CI) of CBD over placebo for the average reduction in seizure frequency was 0.59 (0.52, 0.68; P < .0001) with CLB and 0.85 (0.73, 0.98; P = .0226) without CLB, and the 50% responder rate odds ratio (95% CI) was 2.51 (1.69, 3.71; P < .0001) with CLB and 2.40 (1.38, 4.16; P = .0020) without CLB. Adverse events (AEs) related to somnolence, rash, pneumonia, or aggression were more common in patients with concomitant CLB. There was a significant exposure/response relationship for CBD and its active metabolite. CONCLUSIONS: These results indicate CBD is efficacious with and without CLB, but do not exclude the possibility of a synergistic effect associated with the combination of agents. The safety and tolerability profile of CBD without CLB show a lower rate of certain AEs than with CLB.

EEF1A2 mutations in epileptic encephalopathy/intellectual disability: Understanding the potential mechanism of phenotypic variation.

EEF1A2 encodes protein elongation factor 1-alpha 2, which is involved in Guanosine triphosphate (GTP)-dependent binding of aminoacyl-transfer RNA (tRNA) to the A-site of ribosomes during protein biosynthesis and is highly expressed in the central nervous system. De novo mutations in EEF1A2 have been identified in patients with extensive neurological deficits, including intractable epilepsy, globe developmental delay, and severe intellectual disability. However, the mechanism underlying phenotype variation is unknown. Using next-generation sequencing, we identified a novel and a recurrent de novo mutation, c.294C>A; p.(Phe98Leu) and c.208G>A; p.(Gly70Ser), in patients with Lennox-Gastaut syndrome. The further systematic analysis revealed that all EEF1A2 mutations were associated with epilepsy and intellectual disability, suggesting its critical role in neurodevelopment. Missense mutations with severe molecular alteration in the t-RNA binding sites or GTP hydrolysis domain were associated with early-onset severe epilepsy, indicating that the clinical expression was potentially determined by the location of mutations and alteration of molecular effects. This study highlights the potential genotype-phenotype relationship in EEF1A2 and facilitates the evaluation of the pathogenicity of EEF1A2 mutations in clinical practice.

Lennox-Gastaut Syndrome in Mitochondrial Disease.

PURPOSE: Previous studies have shown that neurologic symptoms are dominant in patients with mitochondrial diseases, and most of these patients have seizure-related disorders. The epileptic classification of these patients as Lennox-Gastaut syndrome (LGS) is as high as 25%. This study aimed to investigate the clinical manifestations, diagnoses, treatments, and epilepsy in LGS, which is associated with mitochondrial disease. MATERIALS AND METHODS: A retrospective study was conducted on 372 patients who were diagnosed with mitochondrial disease between 2006 and 2016. Of these 372 patients, 40 patients diagnosed with LGS were selected, and they were classified into two groups based on the history of West syndrome. Patient characteristics were reviewed, and associations between clinical factors and outcomes after the treatment were analyzed. RESULTS: The proportion of individuals with mitochondrial disease with LGS with a history of West syndrome was 32.5%. Among the patients with mitochondrial disease with LGS, neonatal seizure (p=0.029), seizure as the first symptom (p=0.018), and generalized paroxysmal fast activity frequency on electroencephalogram (p=0.018) in the group with a history of West syndrome were statistically significantly high. The first symptom onset (0.6±0.4 yrs vs. 1.6±0.9 yrs, p=0.003) and first seizure onset (0.9±0.7 yrs vs. 3.9±3.1 yrs, p<0.001) were significantly faster in patients with a history of West syndrome. CONCLUSION: Close monitoring of the medical condition and early intervention might improve the prognosis of individuals with mitochondrial disease with LGS and a history of West syndrome.

[Why the diagnosis of Lennox-Gastaut syndrome is a rare one?] / Pochemu tak redko stavitsia diagnoz sindroma Lennoksa-Gasto?

The review addresses the problem of the diagnosis of Lennox-Gastaut syndrome, a severe epileptic encephalopathy. Despite the presence of a vivid clinical and encephalographic picture, classical Lennox-Gastaut syndrome, which meets all of its diagnostic criteria, is quite rare. Many authors believe that the diagnosis of the syndrome is possible if the patient has tonic seizures and typical ictal and interictal patterns on the electroencephalogram (EEG). The diagnosis of the syndrome is considered probable if there are typical EEG patterns of wakefulness and sleep, but no tonic seizures are recorded. Diagnosis of the syndrome is complicated by its polyetiology (clinical and EEG manifestations can vary significantly), the evolution of seizure types and EEG characteristics as the patient matures, the presence of other epileptic syndromes similar to Lennox-Gastaut syndrome.

Diagnosis switching and outcomes in a cohort of patients with potential epilepsy with myoclonic-atonic seizures.

INTRODUCTION: There is overlap in the electroclinical features of many childhood epilepsy syndromes, especially those presenting with multiple seizure types, such as epilepsy with myoclonic-atonic seizures (EMAS) and Lennox-Gastaut syndrome (LGS). This study aimed to determine the frequency of diagnosis switching and the factors influencing epilepsy syndrome diagnosis in a cohort of children with possible EMAS, as well as to explore the relationship between epilepsy syndrome diagnoses, key electroclinical features, and clinically relevant outcomes. METHODS: This is a cross-sectional retrospective chart review of children treated at the Children's Hospital of Colorado with a potential diagnosis of EMAS. RESULTS: There were 77 patients that met eligibility criteria, including 39% (n = 30) with an initial diagnosis of EMAS and 74% (n = 57) with a final diagnosis of EMAS. On average, for the 65% of patients who received more than one epilepsy diagnosis, the first, second, and third diagnoses were received within one year, three years, and ten years after epilepsy onset, respectively. Final diagnosis was significantly related to obtaining at least a six-month period of seizure freedom, p = 0.03. Classic LGS traits, including paroxysmal fast activity, slow spike-and-wave, and tonic seizures were present in 50% of the overall cohort, although a minority of these patients had a final diagnosis of LGS. However, the presence of more LGS traits was associated with a higher likelihood of ongoing seizures. Adjusted for age of epilepsy onset, seizure freedom was half as likely for every additional LGS trait observed (0.49[0.31, 0.77], p = 0.002). CONCLUSION: Current epilepsy syndrome classification has reduced applicability due to overlapping features. This results in diagnosis switching and limited prognostic value for patients with an overlapping clinical phenotype. Future studies should attempt to stratify patients based not only on epilepsy syndrome diagnosis, but also on the presence of various electroclinical traits to more accurately predict outcome.

Effect of Cannabidiol on Drop Seizures in the Lennox-Gastaut Syndrome.

BACKGROUND: Cannabidiol has been used for treatment-resistant seizures in patients with severe early-onset epilepsy. We investigated the efficacy and safety of cannabidiol added to a regimen of conventional antiepileptic medication to treat drop seizures in patients with the Lennox-Gastaut syndrome, a severe developmental epileptic encephalopathy. METHODS: In this double-blind, placebo-controlled trial conducted at 30 clinical centers, we randomly assigned patients with the Lennox-Gastaut syndrome (age range, 2 to 55 years) who had had two or more drop seizures per week during a 28-day baseline period to receive cannabidiol oral solution at a dose of either 20 mg per kilogram of body weight (20-mg cannabidiol group) or 10 mg per kilogram (10-mg cannabidiol group) or matching placebo, administered in two equally divided doses daily for 14 weeks. The primary outcome was the percentage change from baseline in the frequency of drop seizures (average per 28 days) during the treatment period. RESULTS: A total of 225 patients were enrolled; 76 patients were assigned to the 20-mg cannabidiol group, 73 to the 10-mg cannabidiol group, and 76 to the placebo group. During the 28-day baseline period, the median number of drop seizures was 85 in all trial groups combined. The median percent reduction from baseline in drop-seizure frequency during the treatment period was 41.9% in the 20-mg cannabidiol group, 37.2% in the 10-mg cannabidiol group, and 17.2% in the placebo group (P=0.005 for the 20-mg cannabidiol group vs. placebo group, and P=0.002 for the 10-mg cannabidiol group vs. placebo group). The most common adverse events among the patients in the cannabidiol groups were somnolence, decreased appetite, and diarrhea; these events occurred more frequently in the higher-dose group. Six patients in the 20-mg cannabidiol group and 1 patient in the 10-mg cannabidiol group discontinued the trial medication because of adverse events and were withdrawn from the trial. Fourteen patients who received cannabidiol (9%) had elevated liver aminotransferase concentrations. CONCLUSIONS: Among children and adults with the Lennox-Gastaut syndrome, the addition of cannabidiol at a dose of 10 mg or 20 mg per kilogram per day to a conventional antiepileptic regimen resulted in greater reductions in the frequency of drop seizures than placebo. Adverse events with cannabidiol included elevated liver aminotransferase concentrations. (Funded by GW Pharmaceuticals; GWPCARE3 ClinicalTrials.gov number, NCT02224560 .).

Few individuals with Lennox-Gastaut syndrome have autism spectrum disorder: a comparison with Dravet syndrome.

BACKGROUND: Autism spectrum disorder (ASD) in epilepsy has been a topic of increasing interest, which in general occurs in 15-35% of the patients with epilepsy, more frequently in those with intellectual disability (ID). Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are two typical forms of intractable epileptic encephalopathy associated with ID. We previously reported that ASD was diagnosed in 24.3% of patients with DS, higher in those with profound ID. Given the severe epilepsy and high frequency of ID in LGS, it is necessary to know whether ASD is a common psychomotor co-morbidity of LGS. This study evaluated the autistic behaviors and intelligence in patients with LGS and further compared that between LGS and DS, aiming to understand the complex pathogenesis of epilepsy-ASD-ID triad. METHODS: A total of 50 patients with LGS and 45 patients with DS were enrolled and followed up for at least 3 years. The clinical characteristics were analyzed, and evaluations of ASD and ID were performed. RESULTS: No patients with LGS fully met the diagnostic criteria for ASD, but three of them exhibited more or less autistic behaviors. Majority (86%) of LGS patients presented ID, among which moderate to severe ID was the most common. Early onset age and symptomatic etiology were risk predictors for ID. The prevalence of ASD in LGS was significantly lower than that in DS (0/50 vs. 10/45, p < 0.001), while the prevalence and severity of ID showed no significant difference between the two forms of epileptic encephalopathy. CONCLUSIONS: This study demonstrated a significant difference in the co-morbidity of ASD between LGS and DS, although they had a similar prevalence and severity of ID, refuting the proposal that the prevalence of ASD in epilepsy is accounted for by ID. These findings suggest that the co-morbidity of ASD, ID, and epilepsy may result from multifaceted pathogenic mechanisms.

Hemiconvulsion-hemiplegia-epilepsy evolving to contralateral hemi-Lennox-Gastaut-like phenotype.

BACKGROUND: Hemiconvulsion-hemiplegia-epilepsy (HHE) involves infantile-onset acute hemiconvulsive febrile status epilepticus with subsequent unilateral cerebral atrophy and hemiparesis. Chronic epilepsy later develops, typically involving refractory focal seizures; however, the underlying pathophysiology of this epilepsy is not well understood. PATIENT: We present a boy who had a typical acute presentation of HHE at 23 months, but an unusual evolution to chronic epilepsy in which the initially unaffected hemisphere was significantly abnormal. His initial acute presentation was right-sided hemiconvulsive febrile status epilepticus, with subsequent left cerebral hemiatrophy and hemiparesis affecting the right face, arm and leg. Focal seizures began at 5 years and were refractory to medical treatment. At 9 years, video EEG monitoring showed a striking pattern of interictal slow spike-wave and paroxysmal fast activity, maximal over the right, initially unaffected, hemisphere. He had primarily focal tonic seizures involving left-sided stiffening, also appearing to originate from the right hemisphere. Following left functional hemispherotomy he became seizure-free and parents reported improved cognitive function, attention and quality of life. DISCUSSION: This boy had classic features of Lennox-Gastaut syndrome, but expressed almost exclusively over the right hemisphere, which was initially unaffected in his acute presentation of HHE. His evolution to "hemi-Lennox-Gastaut-like phenotype" illustrates the importance of monitoring chronic epilepsy in patients with HHE; early surgical intervention might prevent pathologic recruitment of bilateral secondary networks leading to the refractory seizures and cognitive impairment associated with Lennox-Gastaut syndrome.