Faculty Bibliography

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.

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.

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.

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.

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

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.

Focal cortical dysplasia (FCD) is the most common cause of pediatric epilepsy and the third most common cause in adults with treatment-resistant epilepsy. Surgical resection of the lesion is the most effective treatment to stop seizures. Technical advances in MRI have revolutionized the diagnosis of FCD, leading to high success rates for resective surgery. However, 45% of histologically confirmed FCD patients have normal MRIs (MRI-negative). Without a visible lesion, the success rate of surgery drops from 66% to 29%. In this work, we cast the problem of detecting potential FCD lesions using MRI scans of MRI-negative patients in an image segmentation framework based on hierarchical conditional random fields (HCRF). We use surface based morphometry to model the cortical surface as a two-dimensional surface which is then segmented at multiple scales to extract superpixels of different sizes. Each superpixel is assigned an outlier score by comparing it to a control population. The lesion is detected by fusing the outlier probabilities across multiple scales using a tree-structured HCRF. The proposed method achieves a higher detection rate, with superior recall and precision on a sample of twenty MRI-negative FCD patients as compared to a baseline across four morphological features and their combinations.

Introduction: The role of sleep in learning and memory has gained significant attention in cognitive neuroscience. We report our experience with a healthy subject population at a sleep research center. Methods: We recruited subjects for a daytime nap and overnight sleep study by advertising at an urban university over one year. Subjects were eligible if aged 18 to 35, English-speaking, and scored above 26 on the Montreal Cognitive Assessment (MOCA). They were excluded for any diagnosis of a neurologic or psychiatric disorder, including a sleep disorder (as identified by the insomnia symptom questionnaire, STOP-BANG, and Morningness-Eveningness scale); used psychoactive medications, alcohol or recreational drugs; or recent travel across time zones. Subjects participated in cognitive tasks and slept with simultaneous EEG-PSG, which was scored by a board-certified sleep neurologist. Results: We obtained 40 nap studies and 20 nighttime studies. Screening questionnaires identified eligible subjects with a low risk of insomnia (0.22 +/- 0.52), low r isk of sleep apnea (0.82 +/- 0.75), and inter mediate ci rcadian preferences (47.15 +/- 0.75). There was a wide var iance in sleep efficiency (0.68 +/- 0.29) and total sleep time (TST, 69.86 +/- 33.78 min) during naps; with less variance seen during nocturnal studies (SD 0.84 +/- 0.08; TST 454.13 +/- 45.0 min). Three (15%) nap subjects demonstrated excessive daytime REM. Two nap subjects (5%) and three (15%) nighttime subjects were diagnosed with OSA. One nap subject (2.5%) and two nighttime subjects (10%) were diagnosed with periodic limb movements of sleep (PLMS). Conclusion: Our experience with a healthy subject population suggests a wide variance in daytime sleep behavior and a notable prevalence of sleep disorders such as OSA, PLMS, and excessive daytime REM. These variables should be considered in planning and analysis of sleep and cognition studies

Reports an error in "Cannabidiol in patients with treatment-resistant epilepsy: An open-label interventional trial" by Orrin Devinsky, Eric Marsh, Daniel Friedman, Elizabeth Thiele, Linda Laux, Joseph Sullivan, Ian Miller, Robert Flamini, Angus Wilfong, Francis Filloux, Matthew Wong, Nicole Tilton, Patricia Bruno, Judith Bluvstein, Julie Hedlund, Rebecca Kamens, Jane Maclean, Srishti Nangia, Nilika Shah Singhal, Carey A. Wilson, Anup Patel and Maria Roberta Cilio (The Lancet Neurology, 2016[Mar], Vol 15[3], 270-278). The appendix of this Article has been resupplied to include the correct number of patients at each study site in supplementary table 1. This correction has been made to the online version as of March 7, 2016. (The following abstract of the original article appeared in record 2016-09081-023). 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.