Faculty Bibliography

To present a summary of current scientific evidence about the cannabinoid, cannabidiol (CBD) with regard to its relevance to epilepsy and other selected neuropsychiatric disorders. We summarize the presentations from a conference in which invited participants reviewed relevant aspects of the physiology, mechanisms of action, pharmacology, and data from studies with animal models and human subjects. Cannabis has been used to treat disease since ancient times. Delta9 -Tetrahydrocannabinol (Delta9 -THC) is the major psychoactive ingredient and CBD is the major nonpsychoactive ingredient in cannabis. Cannabis and Delta9 -THC are anticonvulsant in most animal models but can be proconvulsant in some healthy animals. The psychotropic effects of Delta9 -THC limit tolerability. CBD is anticonvulsant in many acute animal models, but there are limited data in chronic models. The antiepileptic mechanisms of CBD are not known, but may include effects on the equilibrative nucleoside transporter; the orphan G-protein-coupled receptor GPR55; the transient receptor potential of vanilloid type-1 channel; the 5-HT1a receptor; and the alpha3 and alpha1 glycine receptors. CBD has neuroprotective and antiinflammatory effects, and it appears to be well tolerated in humans, but small and methodologically limited studies of CBD in human epilepsy have been inconclusive. More recent anecdotal reports of high-ratio CBD:Delta9 -THC medical marijuana have claimed efficacy, but studies were not controlled. CBD bears investigation in epilepsy and other neuropsychiatric disorders, including anxiety, schizophrenia, addiction, and neonatal hypoxic-ischemic encephalopathy. However, we lack data from well-powered double-blind randomized, controlled studies on the efficacy of pure CBD for any disorder. Initial dose-tolerability and double-blind randomized, controlled studies focusing on target intractable epilepsy populations such as patients with Dravet and Lennox-Gastaut syndromes are being planned. Trials in other treatment-resistant epilepsies may also be warranted. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

IMPORTANCE: Sudden unexpected death in epilepsy (SUDEP) is a common cause of mortality in patients with the disease, but it is unknown how neurologists disclose this risk when counseling patients. OBJECTIVE: This study aimed at examining SUDEP discussion practices of neurologists in the U.S. and Canada. DESIGN: An electronic, web-based survey was sent to 17,558 neurologists in the U.S. and Canada. Survey questions included frequency of SUDEP discussion, reasons for discussing/not discussing SUDEP, timing of SUDEP discussions, and perceived patient reactions. We examined factors that influence the frequency of SUDEP discussion and perceived patient response using multivariate logistic regression. PARTICIPANTS: The participants of this study were neurologists who completed postgraduate training and devoted >5% of their time to patient care. RESULTS: There was a response rate of 9.3%; 1200 respondents met eligibility criteria and completed surveys. Only 6.8% of the respondents discussed SUDEP with nearly all (>90% of the time) of their patients with epilepsy/caregivers, while 11.6% never discussed it. Factors that independently predicted whether SUDEP was discussed nearly all of the time were the following: number of patients with epilepsy seen annually (OR=2.01, 95% CI=1.20-3.37, p<0.01) and if the respondent had a SUDEP case in the past 24months (OR=2.27, 95% CI=1.37-3.66, p<0.01). A majority of respondents (59.5%) reported that negative reactions were the most common response to a discussion of SUDEP. Having additional epilepsy/neurophysiology training was associated with an increased risk of a perceived negative response (OR=1.36, 95% CI=1.02-1.82, p=0.038), while years in practice (OR=0.85, 95% CI=0.77-0.95, p<0.005) and seeing both adults and children were associated with a decreased likelihood of negative response (OR=0.15, 95% CI=0.032-0.74, p=0.02). CONCLUSIONS: U.S. and Canadian neurologists rarely discuss SUDEP with all patients with epilepsy/caregivers though discussions are more likely among neurologists who frequently see patients with epilepsy or had a recent SUDEP in their practice. Perceived negative reactions to SUDEP discussions are common but not universal; more experienced neurologists may be less likely to encounter negative reactions, suggesting that there may be ways to frame the discussion that minimizes patient/caregiver distress.

OBJECTIVE: Genetic loss of Tsc1/Tsc2 function in tuberous sclerosis complex (TSC) results in altered mammalian target of rapamycin (mTOR) signaling and abnormal brain development. Although earlier studies have focused on characterization of cortical tubers, in this study we sought to examine the unique cellular and molecular features of the perituberal cortex in order to better understand its contribution to epileptogenesis, cognitive dysfunction, and autism. METHODS: Standard histologic and immunohistochemical labeling was used to assess structural abnormalities and cell-specific pattern of mTORC1 activation in surgically resected cortical tubers and perituberal cortex. Western blotting was performed to quantify the expression of the mTORC1 and mTORC2 biomarkers phospho-S6 (Ser235/236), phospho-S6 (Ser240/244), and phospho-Akt (Ser473), in addition to evaluating the differential expression levels of several neuronal and glial-specific proteins in tubers and peritubers, as compared to non-TSC epilepsy specimens. RESULTS: Tubers demonstrated mild to severe disruption of cortical lamination, the presence of pS6-positive dysplastic neurons and giant cells, an overall increase in mTORC1 and a decrease in mTORC2 activity, increased axonal connectivity and growth, and hypomyelination. Perituberal cortex presented similar histologic, immunohistochemical, and molecular features; however, they were overall milder. Axonal growth was specific for TSC and was negatively correlated with deficient myelination. SIGNIFICANCE: Our results show an extension of cellular dysplasia and dysregulated mTOR signaling in the perituberal tissue, and demonstrate for the first time aberrant connectivity in human TSC brain. This study provides new insights into the pathophysiology of neurologic dysfunction associated with TSC and supports the intrinsic epileptogenicity of normal-appearing perituberal cortex.

OBJECTIVE: We examined the complex relationship between depression, anxiety, and seizure control and quality of life (QOL) outcomes after epilepsy surgery. METHODS: Seven epilepsy centers enrolled 373 patients and completed a comprehensive diagnostic workup and psychiatric and follow-up QOL evaluation. Subjects were evaluated before surgery and then at 3, 6, 12, 24, 48, and 60 months after surgery. Standardized assessments included the Quality of Life in Epilepsy Inventory-89, Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI). A mixed-model repeated-measures analysis was used to analyze associations of depression, anxiety, seizure outcome, and seizure history with overall QOL score and QOL subscores (cognitive distress, physical health, mental health, epilepsy-targeted) prospectively. RESULTS: The groups with excellent and good seizure control showed a significant positive effect on the overall QOL compared to the groups with fair and poor seizure control. The BDI and BAI scores were both highly and negatively associated with overall QOL; increases in BDI and BAI scores were associated with decreased overall QOL score. CONCLUSIONS: Depression and anxiety are strongly and independently associated with worse QOL after epilepsy surgery. Interestingly, even partial seizure control, controlling for depression and anxiety levels, improved QOL. Management of mood and anxiety is a critical component to postsurgical care.

Historically, the study of speech processing has emphasized a strong link between auditory perceptual input and motor production output. A kind of 'parity' is essential, as both perception- and production-based representations must form a unified interface to facilitate access to higher-order language processes such as syntax and semantics, believed to be computed in the dominant, typically left hemisphere. Although various theories have been proposed to unite perception and production, the underlying neural mechanisms are unclear. Early models of speech and language processing proposed that perceptual processing occurred in the left posterior superior temporal gyrus (Wernicke's area) and motor production processes occurred in the left inferior frontal gyrus (Broca's area). Sensory activity was proposed to link to production activity through connecting fibre tracts, forming the left lateralized speech sensory-motor system. Although recent evidence indicates that speech perception occurs bilaterally, prevailing models maintain that the speech sensory-motor system is left lateralized and facilitates the transformation from sensory-based auditory representations to motor-based production representations. However, evidence for the lateralized computation of sensory-motor speech transformations is indirect and primarily comes from stroke patients that have speech repetition deficits (conduction aphasia) and studies using covert speech and haemodynamic functional imaging. Whether the speech sensory-motor system is lateralized, like higher-order language processes, or bilateral, like speech perception, is controversial. Here we use direct neural recordings in subjects performing sensory-motor tasks involving overt speech production to show that sensory-motor transformations occur bilaterally. We demonstrate that electrodes over bilateral inferior frontal, inferior parietal, superior temporal, premotor and somatosensory cortices exhibit robust sensory-motor neural responses during both perception and production in an overt word-repetition task. Using a non-word transformation task, we show that bilateral sensory-motor responses can perform transformations between speech-perception- and speech-production-based representations. These results establish a bilateral sublexical speech sensory-motor system.

OBJECTIVE: Seizures are common in individuals with duplications of chromosome 15q11.2-q13 (Dup15q). The goal of this study was to examine the phenotypes and treatments of seizures in Dup15q in a large population. METHODS: A detailed electronic survey was conducted through the Dup15q Alliance containing comprehensive questions regarding seizures and their treatments in Dup15q. RESULTS: There were 95 responses from Dup15q families. For the 83 with idic(15), 63% were reported to have seizures, of which 81% had multiple seizure types and 42% had infantile spasms. Other common seizure types were tonic-clonic, atonic, myoclonic, and focal. Only 3 of 12 individuals with int dup(15) had seizures. Broad spectrum antiepileptic drugs (AEDs) were the most effective medications, but carbamazepine and oxcarbazepine were also effective, although typical benzodiazepines were relatively ineffective. There was a 24% response rate (>90% seizure reduction) to the first AED tried. For those with infantile spasms, adrenocorticotropic hormone (ACTH) was more effective than vigabatrin. SIGNIFICANCE: This is the largest study assessing seizures in Duplication 15q syndrome, but because this was a questionnaire-based study with a low return rate, it is susceptible to bias. Seizures are common in idic(15) and typically difficult to control, often presenting with infantile spasms and progressing to a Lennox-Gastaut-type syndrome. Seizures in those with int dup(15) are less common, with a frequency similar to the general autism population. In addition to broad spectrum AED, medications such as carbamazepine and oxcarbazepine are also relatively effective in controlling seizures in this population, suggesting a possible multifocal etiology, which may also explain the high rate of infantile spasms. Our small sample suggests a relative lack of efficacy of vigabatrin and other gamma-aminobutyric acid (GABA)ergic medications, such as typical benzodiazepines, which may be attributable to abnormal GABAergic transmission resulting from the duplication of a cluster of GABAbeta3 receptor genes in the 15q11.2-13 region.

There is a lack of consensus regarding how health-care providers should address SUDEP with patients. The purpose of this study was to describe various health-care providers' practices regarding discussion of SUDEP with patients. Separate focus groups were conducted with epileptologists, neurologists, and advanced practice nurses. Across all disciplines, reasons for discussing SUDEP included Practical Accountability, Moral Accountability, Proactivity, and Reactivity. For nurses only, an additional reason was Patient Advocacy. In terms of when not to discuss SUDEP, for all disciplines, and especially the physicians, the theme Not at First emerged. Additional themes that emerged for this question included, in the case of neurologists and epileptologists, Moral Accountability and Out of Options. Ways in which SUDEP is discussed included, in all groups, Discussion and Written Materials. In addition, prevalent in all groups was the finding that procedures for discussing SUDEP with patients and families need to be somewhat standardized. Implications for practice are discussed.

BACKGROUND:: Surgical resection of epileptic foci relies on accurate localization of the epileptogenic zone, often achieved by subdural and depth electrodes. Our epilepsy center has treated selected children with poorly localized medically refractory epilepsy with a staged surgical protocol, with at least one phase of invasive monitoring for localization and resection of epileptic foci. OBJECTIVE:: To evaluate the safety of staged surgical treatments for refractory epilepsy among children. METHODS:: Data were retrospectively collected, including surgical details and complications of all patients who underwent invasive monitoring. RESULTS:: 161 children underwent 200 admissions including staged procedures (>1 surgery during one hospital admission), and 496 total surgeries. Average age at surgery was 7y (8m-16.5y). 250 surgeries included resections (and invasive monitoring), and 189 involved electrode placement only. Cumulative total number of surgeries per patient was 2-10 (average 3). Average duration of monitoring was 10 days (1-30). There were no deaths. Follow-up ranged from 1m to 10y. Major complications included unexpected new permanent mild neurological deficits (2%/admission), CNS or bone flap infections (1.5%/admission), intracranial hemorrhage, CSF leak, and a retained strip (each 0.5%/admission). Minor complications included bone absorption (5%/admission), positive surveillance sub/epidural cultures in asymptomatic patients (5.5%/admission), non-infectious fever (5%/admission), and wound complications (3%/admission). 30 complications necessitated additional surgical treatment. CONCLUSION:: Staged epilepsy surgery, with invasive electrode monitoring, is safe in children with poorly localized medically refractory epilepsy. The rate of major complications is low, and appears comparable to that associated with other elective neurosurgical procedures.

Introduction: About one-third of people with major depressive disorder (MDD) fail at least two antidepressant drug trials within the first year of treatment. 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. Methods: 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 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. We review accumulating evidence linking neurovascular dysfunction with BBB hyperpermeability to primary MDD without neurological comorbidity, and present a theoretical integration between these abnormalities to those involving oxidative stress and neuroinflammation in MDD. Results: Evidence of an association between MDD and neurovascular dysfunction is indirect, deriving primarily from studies assessing peripheral vascular endothelial dysfunction in MDD and from epidemiological data associating MDD with vascular disorders. The relative uptake ratio (RUR) of blood flow after hyperemic challenge has been validated as an index of endothelial function in clinical settings. A prospective cohort showed that the unadjusted mean RUR was significantly lower among 23 participants with MDD and 23 with minor depressive disorder compared with 277 nondepressed controls (P = .001); this effect remained significant after adjusting for age, sex, socioeconomic factors, medical comorbidity, andmedications (P!