Faculty Bibliography

Psychiatric and behavioral disorders are important aspects of epilepsy and have received increasing attention in the last several years. The literature upon which most of the field relies contains some biases that must be carefully examined and resolved in future studies. First, in the pediatric epilepsy literature, many reports find that children with epilepsy have high levels of behavioral and psychiatric disorders when compared to appropriate controls. Most of these studies rely on parent-proxy completed instruments to assess these behavioral endpoints. Parents' reports are not objective but reflect parents' reactions and emotions. Increasing evidence suggests inherent biases in proxy reports and highlights the need to assess children directly. Second, periictal phenomena may be mischaracterized as underlying mood disorders. Third, many studies report elevated levels of psychiatric morbidity before and after the diagnosis of epilepsy, suggesting an inherent relation between the two types of disorders. Psychogenic nonepileptic seizures, while widely recognized as posing a diagnostic dilemma in the clinic, may account for some of these research findings. Diagnostic errors between epilepsy and psychogenic nonepileptic seizures need careful consideration when evaluating studies demonstrating associations between psychiatric disorders and epilepsy or poorer seizure control in association with psychiatric disorders in people who have epilepsy. Mental health concerns are important for everyone. An accurate, undistorted understanding of the relation between mental health disorders and epilepsy is essential to ensure appropriate therapy and to avoid unnecessary and potentially harmful treatments and common misconceptions.

Objective: Assess the effect of adjunctive CBD for treatment of drug-resistant seizures in Dravet syndrome. Methods: This double-blind, placebo-controlled trial randomized 120 children aged 2-18 years with Dravet syndrome and drug-resistant seizures to receive CBD oral solution 20 mg/kg/ day (n=61) or placebo (n=59) for 14 weeks (2 week titration; 12 week maintenance). The primary endpoint was the percentage change from baseline in convulsive seizures (tonic-clonic, tonic, clonic, and atonic) frequency over the 14-week treatment period. Results: The groups were well-balanced at baseline for demographics. Mean age was 10 years, with 29% of patients <6 years. Patients had previously tried a median 4 AEDs, and were currently taking a median 3 AEDs. Convulsive seizure frequency per month decreased from a median of 12.4 to 5.9 (median reduction of 39%) with CBD versus 14.9 to 14.1 (median reduction of 13%) with placebo (difference between groups of 23%; p=0.012). The proportion of patients with e50% reduction in convulsive seizure frequency was 42.6% with CBD versus 27.1% with placebo (OR=2.0; p=0.078). Adverse events (AEs) occurred in 93.4% of CBD and 74.6% of placebo patients, and were mostly mild or moderate; the most common were somnolence, diarrhea, and decreased appetite. Serious AEs were reported in 16.4% of CBD and 5.1% of placebo patients, and were considered treatment-related in 8.2% of CBD patients, all of whom discontinued CBD. Some elevations in transaminases were noted without elevations of bilirubin; all were on concomitant valproate and all resolved. There were no deaths in the study. Conclusions: In this study, CBD resulted in a significantly greater reduction in convulsive seizure frequency than placebo; adverse events were more frequent with CBD, but it was generally well tolerated

In this exciting era, we are coming closer and closer to bringing an anti-inflammatory therapy to the clinic for the purpose of seizure prevention, modification, and/or suppression. At present, it is unclear what this approach might entail, and what form it will take. Irrespective of the therapy that ultimately reaches the clinic, there will be some commonalities with regard to clinical trials. A number of animal models have now been used to identify inflammation as a major underlying mechanism of both chronic seizures and the epileptogenic process. These models have demonstrated that specific anti-inflammatory treatments can be effective at both suppressing chronic seizures and interfering with the process of epileptogenesis. Some of these have already been evaluated in early phase clinical trials. It can be expected that there will soon be more clinical trials of both "conventional, broad spectrum" anti-inflammatory agents and novel new approaches to utilizing specific anti-inflammatory therapies with drugs or other therapeutic interventions. A summary of some of those approaches appears below, as well as a discussion of the issues facing clinical trials in this new domain.

Tuberous sclerosis complex (TSC) is a rare genetic disease causing multisystem growth of benign tumours and other hamartomatous lesions, which leads to diverse and debilitating clinical symptoms. Patients are born with TSC1 or TSC2 mutations, and somatic inactivation of wild-type alleles drives MTOR activation; however, second hits to TSC1/TSC2 are not always observed. Here, we present the genomic landscape of TSC hamartomas. We determine that TSC lesions contain a low somatic mutational burden relative to carcinomas, a subset feature large-scale chromosomal aberrations, and highly conserved molecular signatures for each type exist. Analysis of the molecular signatures coupled with computational approaches reveals unique aspects of cellular heterogeneity and cell origin. Using immune data sets, we identify significant neuroinflammation in TSC-associated brain tumours. Taken together, this molecular catalogue of TSC serves as a resource into the origin of these hamartomas and provides a framework that unifies genomic and transcriptomic dimensions for complex tumours.

Importance: Children with benign epilepsy with centrotemporal spikes (BECTS) have traditionally been considered to have a uniformly good prognosis. However, benign may be a misnomer because BECTS is linked to cognitive deficits, a more severe phenotype with intractable seizures, and the potential for sudden unexpected death in epilepsy (SUDEP). Objective: To determine if cases of BECTS are present in the North American SUDEP Registry (NASR). Design, Setting, and Participants: The NASR is a clinical and biospecimen repository established in 2011 to promote SUDEP research. The NASR database, which includes medical records, results of electroencephalographic tests, and interviews with family members of patients with epilepsy who died suddenly without other identifiable causes of death, was queried from June 3, 2011, to June 3, 2016, for cases of BECTS. The patients with epilepsy had died suddenly without other identifiable causes of death (eg, drowning, trauma, exposure to toxic substances, or suicide); SUDEP classification was determined by the consensus of 2 epileptologists. Main Outcomes and Measures: Cases of SUDEP among children who received a diagnosis of BECTS among patients reported in the NASR. Results: Three boys (median age at death, 12 years; range, 9-13 years) who received a diagnosis of BECTS by their pediatric epileptologist or neurologists were identified among 189 cases reported in the NASR. The median age of epilepsy onset was 5 years (range, 3-11 years), and the median duration of epilepsy was 4 years (range, 1-10 years). Two deaths were definite SUDEP, and 1 was probable SUDEP. Independent review of clinical and electroencephalographic data supported the diagnosis of BECTS in all 3 patients. None of the patients was prescribed antiseizure drugs, either owing to physician recommendation or mutual decision by the physician and parents. All 3 patients were found dead in circumstances typical of SUDEP. The 3 patients spanned the spectrum of BECTS severity: 1 had only a few seizures, 1 had more than 30 focal motor seizures, and 1 had 4 witnessed generalized tonic-clonic seizures and approximately 30 suspected generalized tonic-clonic seizures. Conclusions and Relevance: Sudden unexpected death in epilepsy is a very rare outcome in BECTS that clinicians should consider discussing in appropriate circumstances and possibly factoring into treatment decisions.

The classic epileptic encephalopathies, including infantile spasms (IS) and Lennox-Gastaut syndrome (LGS), are severe seizure disorders that usually arise sporadically. De novo variants in genes mainly encoding ion channel and synaptic proteins have been found to account for over 15% of patients with IS or LGS. The contribution of autosomal recessive genetic variation, however, is less well understood. We implemented a rare variant transmission disequilibrium test (TDT) to search for autosomal recessive epileptic encephalopathy genes in a cohort of 320 outbred patient-parent trios that were generally prescreened for rare metabolic disorders. In the current sample, our rare variant transmission disequilibrium test did not identify individual genes with significantly distorted transmission over expectation after correcting for the multiple tests. While the rare variant transmission disequilibrium test did not find evidence of a role for individual autosomal recessive genes, our current sample is insufficiently powered to assess the overall role of autosomal recessive genotypes in an outbred epileptic encephalopathy population

BACKGROUND: The Dravet syndrome is a complex childhood epilepsy disorder that is associated with drug-resistant seizures and a high mortality rate. We studied cannabidiol for the treatment of drug-resistant seizures in the Dravet syndrome. METHODS: In this double-blind, placebo-controlled trial, we randomly assigned 120 children and young adults with the Dravet syndrome and drug-resistant seizures to receive either cannabidiol oral solution at a dose of 20 mg per kilogram of body weight per day or placebo, in addition to standard antiepileptic treatment. The primary end point was the change in convulsive-seizure frequency over a 14-week treatment period, as compared with a 4-week baseline period. RESULTS: The median frequency of convulsive seizures per month decreased from 12.4 to 5.9 with cannabidiol, as compared with a decrease from 14.9 to 14.1 with placebo (adjusted median difference between the cannabidiol group and the placebo group in change in seizure frequency, -22.8 percentage points; 95% confidence interval [CI], -41.1 to -5.4; P=0.01). The percentage of patients who had at least a 50% reduction in convulsive-seizure frequency was 43% with cannabidiol and 27% with placebo (odds ratio, 2.00; 95% CI, 0.93 to 4.30; P=0.08). The patient's overall condition improved by at least one category on the seven-category Caregiver Global Impression of Change scale in 62% of the cannabidiol group as compared with 34% of the placebo group (P=0.02). The frequency of total seizures of all types was significantly reduced with cannabidiol (P=0.03), but there was no significant reduction in nonconvulsive seizures. The percentage of patients who became seizure-free was 5% with cannabidiol and 0% with placebo (P=0.08). Adverse events that occurred more frequently in the cannabidiol group than in the placebo group included diarrhea, vomiting, fatigue, pyrexia, somnolence, and abnormal results on liver-function tests. There were more withdrawals from the trial in the cannabidiol group. CONCLUSIONS: Among patients with the Dravet syndrome, cannabidiol resulted in a greater reduction in convulsive-seizure frequency than placebo and was associated with higher rates of adverse events. (Funded by GW Pharmaceuticals; ClinicalTrials.gov number, NCT02091375 .).

The differential contribution of medial-temporal lobe regions to verbal declarative memory is debated within the neuroscience, neuropsychology, and cognitive psychology communities. We evaluate whether the extent of surgical resection within medial-temporal regions predicts longitudinal verbal learning and memory outcomes. This single-center retrospective observational study involved patients with refractory temporal lobe epilepsy undergoing unilateral anterior temporal lobe resection from 2007 to 2015. Thirty-two participants with Engel Classes 1 and 2 outcomes were included (14 left, 18 right) and followed for a mean of 2.3 years after surgery (+/-1.5 years). Participants had baseline and postsurgical neuropsychological testing and high-resolution T1-weighted MRI scans. Postsurgical lesions were manually traced and coregistered to presurgical scans to precisely quantify resection extent of medial-temporal regions. Verbal learning and memory change scores were regressed on hippocampal, entorhinal, and parahippocampal resection volume after accounting for baseline performance. Overall, there were no significant differences in learning and memory change between patients who received left and right anterior temporal lobe resection. After controlling for baseline performance, the extent of left parahippocampal resection accounted for 27% (p = .021) of the variance in verbal short delay free recall. The extent of left entorhinal resection accounted for 37% (p = .004) of the variance in verbal short delay free recall. Our findings highlight the critical role that the left parahippocampal and entorhinal regions play in recall for verbal material.