Faculty Bibliography

Epileptic encephalopathies are a devastating group of severe childhood epilepsy disorders for which the cause is often unknown. Here we report a screen for de novo mutations in patients with two classical epileptic encephalopathies: infantile spasms (n = 149) and Lennox-Gastaut syndrome (n = 115). We sequenced the exomes of 264 probands, and their parents, and confirmed 329 de novo mutations. A likelihood analysis showed a significant excess of de novo mutations in the ∼4,000 genes that are the most intolerant to functional genetic variation in the human population (P = 2.9 × 10(-3)). Among these are GABRB3, with de novo mutations in four patients, and ALG13, with the same de novo mutation in two patients; both genes show clear statistical evidence of association with epileptic encephalopathy. Given the relevant site-specific mutation rates, the probabilities of these outcomes occurring by chance are P = 4.1 × 10(-10) and P = 7.8 × 10(-12), respectively. Other genes with de novo mutations in this cohort include CACNA1A, CHD2, FLNA, GABRA1, GRIN1, GRIN2B, HNRNPU, IQSEC2, MTOR and NEDD4L. Finally, we show that the de novo mutations observed are enriched in specific gene sets including genes regulated by the fragile X protein (P < 10(-8)), as has been reported previously for autism spectrum disorders.

Whole exome sequencing using a parent-child trio design to identify de novo mutations provides an efficient method to identify novel genes for rare diseases with low reproductive fitness that are difficult to study by more classical genetic methods of linkage analysis. We describe a 15 y old female with severe static encephalopathy, intellectual disability, and generalized epilepsy. After extensive metabolic and genetic testing, whole exome sequencing identified a novel de novo variant in Synaptosomal-associated protein-25 (SNAP25), c.142G > T p.Phe48Val alteration. This variant is predicted to be damaging by all prediction algorithms. SNAP25 is part of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein complex which is involved in exocytotic release of neurotransmitters. Genetic alterations in Snap25 in animal models can cause anxiety-related behavior, ataxia and seizures. We suggest that SNAP25 mutations in humans are a novel genetic cause of intellectual disability and epilepsy.

Advances in MRI have transformed the in vivo detection of brain abnormalities in neurological disease. However, many subtle structural abnormalities remain undetected, especially in individual patients, where clinical relevance is highest. We present a quantitative, multifeature morphometry approach combined with machine learning algorithms for detecting structural cortical abnormalities in epilepsy patients with focal cortical dysplasia (FCD). FCD is a malformation of cortical development and is the most common etiology in pediatric epilepsy and the second most common etiology in adults with treatment resistant epilepsy. Lesions may occur anywhere in cortex. Seizure freedom after surgery is reported at 66% with a detected lesion, but only 29% in MRI-negative patients. Yet, 70% to 80% of histologically confirmed FCD cases go undetected by visual inspection of the MRI. Sixty-one controls and 23 MRI-negative patients in whom no focal lesion was detected during routine visual radiological analysis and 7 MRI-positive patients were scanned before surgery at 3 T using a T1-weighted MRI sequence. All patients subsequently underwent intracranial EEG monitoring and resection of the epileptic focus and pathology confirmed FCD. Morphometric routines with surface-based spherical averaging techniques were used to align anatomical structures between individual brains and to calculate 6 features at each vertex, including cortical thickness, gray-white contrast, local gyrification, sulcal depth, Jacobian distance, and curvature. A logistic regression classifier was trained on normal control data and the data from the FCD region of MRI-positive patients to classify, in MRI-negative patients, vertices into lesional and nonlesional. The logistic regression approach correctly classified lesions within the resection zone in 14 out of the 24 (58%) MRInegative patients. The overall false positive rate (by vertex) was never greater than 1.05%. Quantitative MRI can aid in the presurgical detection of FCD lesions, even !

BACKGROUND: Epilepsy is a common neurological disorder that affects approximately 50 million people worldwide. Both risk of epilepsy and response to treatment partly depend on genetic factors, and gene identification is a promising approach to target new prediction, treatment, and prevention strategies. However, despite significant progress in the identification of genes causing epilepsy in families with a Mendelian inheritance pattern, there is relatively little known about the genetic factors responsible for common forms of epilepsy and so-called epileptic encephalopathies. Study design The Epilepsy Phenome/Genome Project (EPGP) is a multi-institutional, retrospective phenotype-genotype study designed to gather and analyze detailed phenotypic information and DNA samples on 5250 participants, including probands with specific forms of epilepsy and, in a subset, parents of probands who do not have epilepsy. RESULTS: EPGP is being executed in four phases: study initiation, pilot, study expansion/establishment, and close-out. This article discusses a number of key challenges and solutions encountered during the first three phases of the project, including those related to (1) study initiation and management, (2) recruitment and phenotyping, and (3) data validation. The study has now enrolled 4223 participants. CONCLUSIONS: EPGP has demonstrated the value of organizing a large network into cores with specific roles, managed by a strong Administrative Core that utilizes frequent communication and a collaborative model with tools such as study timelines and performance-payment models. The study also highlights the critical importance of an effective informatics system, highly structured recruitment methods, and expert data review.

About one-third of people with major depressive disorder (MDD) fail at least two antidepressant drug trials at 1 year. Together with clinical and experimental evidence indicating that the pathophysiology of MDD is multifactorial, this observation underscores the importance of elucidating mechanisms beyond monoaminergic dysregulation that can contribute to the genesis and persistence of MDD. Oxidative stress and neuroinflammation are mechanistically linked to the presence of neurovascular dysfunction with blood-brain barrier (BBB) hyperpermeability in selected neurological disorders, such as stroke, epilepsy, multiple sclerosis, traumatic brain injury, and Alzheimer's disease. In contrast to other major psychiatric disorders, MDD is frequently comorbid with such neurological disorders and constitutes an independent risk factor for morbidity and mortality in disorders characterized by vascular endothelial dysfunction (cardiovascular disease and diabetes mellitus). Oxidative stress and neuroinflammation are implicated in the neurobiology of MDD. More recent evidence links neurovascular dysfunction with BBB hyperpermeability to MDD without neurological comorbidity. We review this emerging literature and present a theoretical integration between these abnormalities to those involving oxidative stress and neuroinflammation in MDD. We discuss our hypothesis that alterations in endothelial nitric oxide levels and endothelial nitric oxide synthase uncoupling are central mechanistic links in this regard. Understanding the contribution of neurovascular dysfunction with BBB hyperpermeability to the pathophysiology of MDD may help to identify novel therapeutic and preventative approaches.

Rationale: Tuberous Sclerosis Complex (TSC) is a multisystem autosomal dominant disease caused by inactivating mutations in TSC1 or TSC2 genes. The most common neurological symptoms in TSC include treatment-resistant epilepsy, mental retardation and autism. There is now accumulating evidence that pro-inflammatory cytokines, produced and released mainly by reactive astrocytes and activated microglia, are implicated in a wide range of chronic neurological disorders, including refractory epilepsy. The purpose of this study was to evaluate the degree of inflammation in TSC brain lesions in human, with the hypothesis that activated glial cells and pro-inflammatory cytokines will be increased in both cortical tubers and peri-tuberal brain (PTB), possibly contributing to widespread network dysfunction. Methods: Human TSC specimens (n=10; ages 0-7 years) were prospectively collected following epilepsy surgery at NYULMC. Region-matched control autopsy brain samples from cases with normal neurological history were obtained from the Maryland Brain and Tissue Bank (n=7; ages 0-8 years). Tissue samples were collected and handled in accordance with the NYULMC Institutional Review Board. Fresh frozen specimens were used to prepare protein extracts for Western blotting. Blots were probed with the astrocytic and microglial markers GFAP and Iba1, as well as with the proinflammatory cytokines interleukin 1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha). To determine statistical significance (p<0.05), oneway ANOVA followed by Student's t-test were used. Results: GFAP and Iba1 levels were significantly elevated in both tubers (343+/-115% of control, n=5; p<0.05 for GFAP, and 346+/-35% of control, n=5; p<0.0001 for Iba1) and PTB (225+/-37% of control, n=5; p<0.001 for GFAP, and 247+/-37% of control, n=5; p<0.001 for Iba1). The inactive pro-IL-1beta was highly upregulated in tubers (319+/-114% of control, n=6; p<0.05) and in PTB (228+/-70% of control, n=4; p<0.001), and this was accompanied by a commensur!

Rationale: Autism spectrum disorders (ASDs), characterized by impaired social interactions, impaired communication and stereotyped behaviors, are highly associated with epilepsy (up to 38%). A shift in cortical excitatory/inhibitory balance towards increased excitation and/or decreased inhibition may play a key role in the pathophysiology of both ASDs and epilepsy. We hypothesized that differences in AMPA receptor (AMPAR) and NMDA receptor (NMDAR) subunit expression in ASD and epilepsy patients may represent a basis for distinct clinical neurological manifestations. Identifying specific synaptic mechanisms for autism and epilepsy will allow development of targeted therapies. Methods: Brain specimens from treatment-resistant temporal lobe epilepsy cases were collected prospectively during resective surgery at NYULMC (n=5; ages 21-37 years). Autopsy temporal and frontal lobe samples from ASD patients (n=5; ages 4-22 years) and regionmatched control specimens from cases with normal neurological history (n=10; ages 5-48 years) were obtained from Maryland Brain and Tissue Bank. All ASD cases met the standard diagnostic criteria (Autism Diagnostic Interview-Revised) and had no evidence of epilepsy, while none of the epilepsy patients were diagnosed with autism. The levels of the NMDAR and AMPAR subunits (NR1, NR2A, NR2B, GluR1 and GluR2) were quantified by Western blot and compared among groups (one-way ANOVA and t-tests). Results: Temporal lobe cortex analysis demonstrated a significant increase in NR1 expression in autism patients (288% of control; p<0.0001), but no significant change in epilepsy cases (96% of control; p>0.05). In both groups, NR2A was significantly decreased (ca. 40% of control; p<0.0001), while NR2B demonstrated a significant upregulation (255% of control in autism and 511% of control in epilepsy; p<0.0001). NR2B levels were significantly higher in epilepsy, relative to autism patients (p<0.001). GluR1 expression was increased in both autism (388% of control; p<0.0001) and epilep!

Rationale: Controversy remains as to whether or not neurologists should discuss SUDEP with all epilepsy patients or only those at high risk. We initiated a web-based survey to determine whether persons with epilepsy (PWE) and caregivers of PWE (C-PWE) want to know about SUDEP from their medical providers and when they want to learn about it. Methods: An online survey for adult PWE and C-PWE was designed based on a previous survey of neurologists (Friedman et al, 2012; AES abstract). Respondents were solicited from an email blast and newsletter sent to Epilepsy Therapy Project (ETP) members. A survey link was also posted on epilepsy.com. The survey was IRB approved. Results: 1,325 PWE and 574 C-PWE completed at least some of the survey. Demographic features and epilepsy-related factors are summarized in Table 1Attitudes and knowledge of SUDEP are summarized in Table 2Of the PWE respondents. 57% worry at least a little about dying from their epilepsy and 68% heard about SUDEP before the survey. of these 68%, 52% learned of SUDEP from the internet, only 9.6% from their epilepsy doctor; only 29% feel welleducated about it; 46% don't know whether they are at risk; and 69% never discussed SUDEP with their doctor. of the 32% who had not heard of SUDEP, 50% were scared, anxious or sad after reading the definition but only 3% did not want to ever be told about SUDEP. 65% will go to their epilepsy doctor for more information. of the responding C-PWE, 92% worry at least a little about the PWE dying from epilepsy. 80% had heard about SUDEP before our survey and 55% of these learned about it from the internet and 11.8% from the epilepsy doctor. Only 28% felt well-educated about it; 64% think the PWE is at risk for SUDEP; and 55% never discussed SUDEP with the doctor. of the 20% that had not heard of SUDEP prior to our survey, 92% were scared, anxious or sad after reading the definition but only 1% did not want to ever be told about SUDEP. 83% will go to their epilepsy doctor for more information. Conclusion!