Faculty Bibliography

PURPOSE: A UCB-IBM collaboration explored the application of machine learning to large claims databases to construct an algorithm for antiepileptic drug (AED) choice for individual patients. METHODS: Claims data were collected between January 2006 and September 2011 for patients with epilepsy >16years of age. A subset of patient claims with a valid index date of AED treatment change (new, add, or switch) were used to train the AED prediction model by retrospectively evaluating an index date treatment for subsequent treatment change. Based on the trained model, a model-predicted AED regimen with the lowest likelihood of treatment change was assigned to each patient in the group of test claims, and outcomes were evaluated to test model validity. RESULTS: The model had 72% area under receiver operator characteristic curve, indicating good predictive power. Patients who were given the model-predicted AED regimen had significantly longer survival rates (time until a treatment change event) and lower expected health resource utilization on average than those who received another treatment. The actual prescribed AED regimen at the index date matched the model-predicted AED regimen in only 13% of cases; there were large discrepancies in the frequency of use of certain AEDs/combinations between model-predicted AED regimens and those actually prescribed. CONCLUSIONS: Chances of treatment success were improved if patients received the model-predicted treatment. Using the model's prediction system may enable personalized, evidence-based epilepsy care, accelerating the match between patients and their ideal therapy, thereby delivering significantly better health outcomes for patients and providing health-care savings by applying resources more efficiently. Our goal will be to strengthen the predictive power of the model by integrating diverse data sets and potentially moving to prospective data collection.

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in individuals with chronic, uncontrolled epilepsy. Epidemiologists use information on death certificates to study SUDEP. Certification of seizure-related deaths varies. Multiple classification schemes have been proposed to categorize SUDEP type deaths. Nashef et al. recently proposed categorizing death into Definite SUDEP, Definite SUDEP Plus, Probable SUDEP, Possible SUDEP, Near-SUDEP, and Not SUDEP. This study analyzes certification of seizure-related deaths by our office and considers how it relates to Nashef's classifications. Investigative reports from 2011-2015 from the archives of the Jefferson County Coroner/Medical Examiner's Office were searched for the terms "seizure(s)" and "epilepsy." Cases (N=61) were categorized as Definite SUDEP (n=13), Definite SUDEP Plus (n=12), Probable SUDEP (n=1), Possible SUDEP (n=2), and Not SUDEP (n=33). The term SUDEP was only used in one case of Definite SUDEP. The other 12 cases were certified with variations of terms "seizure" and "epilepsy." Cases categorized as Definite SUDEP Plus were overwhelmingly certified as deaths due to heart disease. Categories Probable SUDEP or Possible SUDEP comprised three cases, and in one of those a seizure-related term was used on the death certificate. Thirty-three cases were classified as Not SUDEP. The finding that the majority of cases of Definite SUDEP were certified as some variation of "seizure" or "epilepsy" but not "SUDEP" has important implications for SUDEP research. Our study also suggests that cases of Definite SUDEP Plus would be difficult for epidemiologists to identify because cardiovascular diseases are more frequently implicated.

INTRODUCTION: Felbamate was approved in 1993 to treat partial seizures with and without secondary generalization in adults and in Lennox-Gastaut Syndrome in children. Its use was later restricted when rare but fatal cases of aplastic anemia and hepatic failure were identified. METHODS: This single center analysis retrospectively evaluated the safety and efficacy of felbamate in a cohort of children, adolescents, and adults with epilepsy. RESULTS: A chart review identified 103 patients taking felbamate. The range of felbamate dose was 300-4500mg (mean: 1800+/-900mg). The duration of therapy ranged from 1month to 20years (mean duration: 35+/-45months). Eighteen (17.5%) subjects experienced adverse events including insomnia, nausea, vomiting, decreased appetite, weight loss, gastric discomfort, diarrhea, mood and behavioral problems, high blood pressure, headache, and elevated liver enzymes. Out of these, 6 (5.9%) patients discontinued the therapy. No hepatic failure or agranulocytosis was observed. Fifty-nine (57.72%) patients achieved >/=50% reduction in seizure frequency, and 30 (29.12%) patients achieved seizure freedom. CONCLUSIONS: These findings suggest that felbamate is safe, well tolerated, and effective in treatment of various types of epilepsy syndromes.

BACKGROUND: Almost a third of patients with epilepsy have a treatment-resistant form, which is associated with severe morbidity and increased mortality. Cannabis-based treatments for epilepsy have generated much interest, but scientific data are scarce. We aimed to establish whether addition of cannabidiol to existing anti-epileptic regimens would be safe, tolerated, and efficacious in children and young adults with treatment-resistant epilepsy. METHODS: In this open-label trial, patients (aged 1-30 years) with severe, intractable, childhood-onset, treatment-resistant epilepsy, who were receiving stable doses of antiepileptic drugs before study entry, were enrolled in an expanded-access programme at 11 epilepsy centres across the USA. Patients were given oral cannabidiol at 2-5 mg/kg per day, up-titrated until intolerance or to a maximum dose of 25 mg/kg or 50 mg/kg per day (dependent on study site). The primary objective was to establish the safety and tolerability of cannabidiol and the primary efficacy endpoint was median percentage change in the mean monthly frequency of motor seizures at 12 weeks. The efficacy analysis was by modified intention to treat. Comparisons of the percentage change in frequency of motor seizures were done with a Mann-Whitney U test. RESULTS: Between Jan 15, 2014, and Jan 15, 2015, 214 patients were enrolled; 162 (76%) patients who had at least 12 weeks of follow-up after the first dose of cannabidiol were included in the safety and tolerability analysis, and 137 (64%) patients were included in the efficacy analysis. In the safety group, 33 (20%) patients had Dravet syndrome and 31 (19%) patients had Lennox-Gastaut syndrome. The remaining patients had intractable epilepsies of different causes and type. Adverse events were reported in 128 (79%) of the 162 patients within the safety group. Adverse events reported in more than 10% of patients were somnolence (n=41 [25%]), decreased appetite (n=31 [19%]), diarrhoea (n=31 [19%]), fatigue (n=21 [13%]), and convulsion (n=18 [11%]). Five (3%) patients discontinued treatment because of an adverse event. Serious adverse events were reported in 48 (30%) patients, including one death-a sudden unexpected death in epilepsy regarded as unrelated to study drug. 20 (12%) patients had severe adverse events possibly related to cannabidiol use, the most common of which was status epilepticus (n=9 [6%]). The median monthly frequency of motor seizures was 30.0 (IQR 11.0-96.0) at baseline and 15.8 (5.6-57.6) over the 12 week treatment period. The median reduction in monthly motor seizures was 36.5% (IQR 0-64.7). INTERPRETATION: Our findings suggest that cannabidiol might reduce seizure frequency and might have an adequate safety profile in children and young adults with highly treatment-resistant epilepsy. Randomised controlled trials are warranted to characterise the safety profile and true efficacy of this compound. FUNDING: GW Pharmaceuticals, Epilepsy Therapy Project of the Epilepsy Foundation, Finding A Cure for Epilepsy and Seizures.

Epilepsy is associated with a high rate of premature mortality from direct and indirect effects of seizures, epilepsy, and antiseizure therapies. Sudden unexpected death in epilepsy (SUDEP) is the second leading neurologic cause of total lost potential life-years after stroke, yet SUDEP may account for less than half of all epilepsy-related deaths. Some epilepsy groups are especially vulnerable: individuals from low socioeconomic status groups and those with comorbid psychiatric illness die more often than controls. Despite clear evidence of an important public health problem, efforts to assess and prevent epilepsy-related deaths remain inadequate. We discuss factors contributing to the underestimation of SUDEP and other epilepsy-related causes of death. We suggest the need for a systematic classification of deaths directly due to epilepsy (e.g., SUDEP, drowning), due to acute symptomatic seizures, and indirectly due to epilepsy (e.g., suicide, chronic effects of antiseizure medications). Accurately estimating the frequency of epilepsy-related mortality is essential to support the development and assessment of preventive interventions. We propose that educational interventions and public health campaigns targeting medication adherence, psychiatric comorbidity, and other modifiable risk factors may reduce epilepsy-related mortality. Educational campaigns regarding sudden infant death syndrome and fires, which kill far fewer Americans than epilepsy, have been widely implemented. We have done too little to prevent epilepsy-related deaths. Everyone with epilepsy and everyone who treats people with epilepsy need to know that controlling seizures will save lives.

The male:female ratio in autism spectrum disorder (ASD) averages greater than 4:1 while the male:female ratio of ASD with epilepsy averages less than 3:1. This indicates an elevated risk of epilepsy in females with ASD; yet, it is unknown whether phenotypic features of epilepsy and ASD differ between males and females with this comorbidity. The goal of this study is to investigate sex differences in phenotypic features of epilepsy and ASD in a prospective sample of 130 children and young adults with an initial ASD diagnosis and subsequent epilepsy diagnosis. All participants were characterized by standardized diagnostic inventories, parent/caregiver completed questionnaires, and medical/academic record review. Diagnostic classifications of epilepsy, ASD, and intellectual disability were performed by board certified neurologists and a pediatric neuropsychologist. Results demonstrated a lower male:female ratio (1.8:1) in individuals with ASD and treatment-resistant epilepsy relative to those with ASD and treatment-responsive epilepsy (4.9:1), indicating a higher risk of treatment-resistant epilepsy in females. Mild neuroimaging abnormalities were more common in females than males and this was associated with increased risk of treatment-resistance. In contrast, ASD symptom severity was lower in females compared with males. Findings distinguish females with ASD and epilepsy as a distinct subgroup at higher risk for a more severe epilepsy phenotype in the context of a less severe ASD phenotype. Increased risk of anti-epileptic treatment resistance in females with ASD and epilepsy suggests that comprehensive genetic, imaging, and neurologic screening and enhanced treatment monitoring may be indicated for this subgroup. Autism Res 2015. (c) 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Parents of children with chromosome 15q duplication syndrome (Dup15q) have anecdotally reported high pain threshold as a feature of the disorder. The purpose of this study was to document parental-reported estimates of the frequency of high pain tolerance and the stimuli that fail to evoke a normal pain response. We sent an online survey to 840 families with children with Dup15q to explore the frequency and clinical manifestations of high pain threshold. There were 216 respondents (25.7%). A high pain threshold was reported in 87% of children at some time. There was a trend (p=0.06) for high pain threshold to be more commonly observed among children with the isodicentric (85.6%) and other genetic variants (95%) than interstitial (69.6%) duplications. There was no association between reports of high pain threshold and reports of an intellectual disability (91% of cases), autism spectrum disorder (83% of cases), or self-injurious behavior (40% of cases). Reports included many dramatic cases such as severe burns, broken bones, and electrical traumas, which were associated with little or no evidence of a painful stimulus. A high pain threshold is reported in other disorders associated with intellectual disability and autism; the underlying mechanism in Dup15q and other disorders remains undefined.

INTRODUCTION: Depression and memory dysfunction significantly impact the quality of life of patients with epilepsy. Current therapies for these cognitive and psychiatric comorbidities are limited. We explored the efficacy and safety of transcranial direct current stimulation (TDCS) for treating depression and memory dysfunction in patients with temporal lobe epilepsy (TLE). METHODS: Thirty-seven (37) adults with well-controlled TLE were enrolled in a double-blinded, sham-controlled, randomized, parallel-group study of 5days of fixed-dose (2mA, 20min) TDCS. Subjects were randomized to receive either real or sham TDCS, both delivered over the left dorsolateral prefrontal cortex. Patients received neuropsychological testing and a 20-minute scalp EEG at baseline immediately after the TDCS course and at 2- and 4-week follow-up. RESULTS: There was improvement in depression scores immediately after real TDCS, but not sham TDCS, as measured by changes in the Beck Depression Inventory (BDI change: -1.68 vs. 1.27, p<0.05) and NDDI-E (-0.83 vs. 0.9091, p=0.05). There was no difference between the groups at the 2- or 4-week follow-up. There was no effect on delayed or working memory performance. Transcranial direct current stimulation was well-tolerated and did not increase seizure frequency or interictal discharge frequency. Transcranial direct current stimulation induced an increase in delta frequency band power over the frontal region and delta, alpha, and theta band power in the occipital region after real stimulation compared to sham stimulation, although the difference did not reach statistical significance. DISCUSSION: This study provides evidence for the use of TDCS as a safe and well-tolerated nonpharmacologic approach to improving depressive symptoms in patients with well-controlled TLE. However, there were no changes in memory function immediately following or persisting after a stimulation course. Further studies may determine optimal stimulation parameters for maximal mood benefit.

Purpose: Annegers et al. (2000) reported that the rate of sudden unexpected death in epilepsy (SUDEP) in patients undergoing VNS Therapy decreased from 5.5 per 1000 patient-years (PY) over the first 2 years to 1.7 per 1000 PY thereafter. Since that report, over 80,000 patients with drug-resistant epilepsy have been implanted worldwide, providing the opportunity to revisit the impact of VNS on SUDEP. Methods: This retrospective study included all US patients with drugresistant epilepsy who were implanted with VNS from 1988-2012 with known social security numbers. Exposure to VNS was calculated from date of implant until death, device explant, known date at which the device was disabled or the last follow-up date of December 31, 2012. Occurrence, date and cause of death were obtained from the Social Security Death Index Master File and the National Death Index, which provides ICD-9 or ICD-10 codes. A group of cause-of-death codes was selected as reflecting potential SUDEP and a sample categorized according to Annegers' SUDEP classification. Results: A total of 40,443 patients (mean age at implant: 30.8 years) with a median follow-up of 7.6 years, representing 277,661 PY, were included. A total of 3,689 deaths were recorded, translating into a 13.3/ 1000 PY all-cause mortality rate (SMR=4.58). 953(26%) corresponded to cause-of-death codes that potentially include SUDEP, with a decreasing trend as duration of VNS increased. A preliminary review of a random sample of 200 of these cases adjudicated 109 (54.5%) as possible/ probable/definite SUDEP (1.9/1000 PY). Conclusion: This large mortality study of patients with VNS therapy offers an 80 fold increase in available PY of follow-up as compared to published data. Preliminary findings show crude all-cause mortality rates consistent with those observed in drug-resistant epilepsy. Ongoing analyses will provide specific information regarding SUDEP risk and the impact of VNS therapy