Faculty Bibliography

OBJECTIVE:Sporadic brain arteriovenous malformation (BAVM) is a tangled vascular lesion characterized by direct artery-to-vein connections that can cause life-threatening intracerebral hemorrhage (ICH). Recently, somatic mutations in KRAS have been reported in sporadic BAVM, and mutations in other mitogen-activated protein kinase (MAPK) signaling pathway genes have been identified in other vascular malformations. The objectives of this study were to systematically evaluate somatic mutations in MAPK pathway genes in patients with sporadic BAVM lesions and to evaluate the association of somatic mutations with phenotypes of sporadic BAVM severity. METHODS:The authors performed whole-exome sequencing on paired lesion and blood DNA samples from 14 patients with sporadic BAVM, and 295 genes in the MAPK signaling pathway were evaluated to identify genes with somatic mutations in multiple patients with BAVM. Digital droplet polymerase chain reaction was used to validate KRAS G12V and G12D mutations and to assay an additional 56 BAVM samples. RESULTS:The authors identified a total of 24 candidate BAVM-associated somatic variants in 11 MAPK pathway genes. The previously identified KRAS G12V and G12D mutations were the only recurrent mutations. Overall, somatic KRAS G12V was present in 14.5% of BAVM lesions and G12D was present in 31.9%. The authors did not detect a significant association between the presence or allelic burden of KRAS mutation and three BAVM phenotypes: lesion size (maximum diameter), age at diagnosis, and age at ICH. CONCLUSIONS:The authors confirmed the high prevalence of somatic KRAS mutations in sporadic BAVM lesions and identified several candidate somatic variants in other MAPK pathway genes. These somatic variants may contribute to understanding of the etiology of sporadic BAVM and the clinical characteristics of patients with this condition.

BACKGROUND:Missed or delayed diagnosis of acute stroke, or false-negative stroke (FNS), at initial emergency department (ED) presentation occurs in ≈9% of confirmed stroke patients. Failure to rapidly diagnose stroke can preclude time-sensitive treatments, resulting in higher risks of severe sequelae and disability. In this study, we developed and tested a modified version of a structured medical record review tool, the Safer Dx Instrument, to identify FNS in a subgroup of hospitalized patients with stroke to gain insight into sources of ED stroke misdiagnosis. METHODS:We conducted a retrospective cohort study at 2 unaffiliated comprehensive stroke centers. In the development and confirmatory cohorts, we applied the Safer Stroke-Dx Instrument to report the prevalence and documented sources of ED diagnostic error in FNS cases among confirmed stroke patients upon whom an acute stroke was suspected by the inpatient team, as evidenced by stroke code activation or urgent neurological consultation, but not by the ED team. Inter-rater reliability and agreement were assessed using interclass coefficient and kappa values (κ). RESULTS:Among 183 cases in the development cohort, the prevalence of FNS was 20.2% (95% CI, 15.0-26.7). Too narrow a differential diagnosis and limited neurological examination were common potential sources of error. The interclass coefficient for the Safer Stroke-Dx Instrument items ranged from 0.42 to 0.91, and items were highly correlated with each other. The κ for diagnostic error identification was 0.90 (95% CI, 0.821-0.978) using the Safer Stroke-Dx Instrument. In the confirmatory cohort of 99 cases, the prevalence of FNS was 21.2% (95% CI, 14.2-30.3) with similar sources of diagnostic error identified. CONCLUSIONS:Hospitalized patients identified by stroke codes and requests for urgent neurological consultation represent an enriched population for the study of diagnostic error in the ED. The Safer Stroke-Dx Instrument is a reliable tool for identifying FNS and sources of diagnostic error.

Hypertension is a risk factor for cardiovascular disease. Black women have high rates of hypertension compared to women of other racial or ethnic groups and are disproportionately affected by psychosocial stressors such as racial discrimination, gender discrimination, and caregiving stress. Evidence suggests that stress is associated with incident hypertension and hypertension risk. Stress management is associated with improvements improved blood pressure outcomes. The purpose of this review is to synthesize evidence on effects of stress management interventions on blood pressure in Black women. A comprehensive search of scientific databases was conducted. Inclusion criteria included studies that were: (1) primary research that tested an intervention; (2) in the English language; (3) included African-American women; (4) incorporated stress in the intervention; (5) included blood pressure as an outcome; and (6) were US based. Eighteen studies met inclusion criteria. Ten (56%) studies tested meditation-based interventions, two (11%) tested coping and affirmation interventions, and six (33%) tested lifestyle modification interventions that included stress management content. Thirteen of the studies were randomized controlled trials. Reductions in blood pressure were observed in all of the meditation-based interventions, although the magnitude and statistical significance varied. Comprehensive lifestyle interventions were also efficacious for reducing blood pressure, although the relative contribution of stress management versus behavior modification could not be evaluated. Coping and affirmation interventions did not affect blood pressure. Most of the reviewed studies included small numbers of Black women and did not stratify results by race and gender, so effects remain unclear. This review highlights the urgent need for studies specifically focusing on Black women. Given the extensive disparities in cardiovascular disease morbidity and mortality, whether stress management can lower blood pressure and improve primary and secondary cardiovascular disease prevention among Black women is an important question for future research.

The function of neurons in afferent reception, integration, and generation of electrical activity relies on their strikingly polarized organization, characterized by distinct membrane domains. These domains have different compositions resulting from a combination of selective targeting and retention of membrane proteins. In neurons, most proteins are delivered from their site of synthesis in the soma to the axon via anterograde vesicular transport and undergo retrograde transport for redistribution and/or lysosomal degradation. A key question is whether proteins destined for the same domain are transported in separate vesicles for local assembly or whether these proteins are pre-assembled and co-transported in the same vesicles for delivery to their cognate domains. To assess the content of transport vesicles, one strategy relies on staining of sciatic nerves after ligation, which drives the accumulation of anterogradely and retrogradely transported vesicles on the proximal and distal side of the ligature, respectively. This approach may not permit confident assessment of the nature of the intracellular vesicles identified by staining, and analysis is limited to the availability of suitable antibodies. Here, we use dual color live imaging of proteins labeled with different fluorescent tags, visualizing anterograde and retrograde axonal transport of several proteins simultaneously. These proteins were expressed in rat dorsal root ganglion (DRG) neurons cultured alone or with Schwann cells under myelinating conditions to assess whether glial cells modify the patterns of axonal transport. Advantages of this protocol are the dynamic identification of transport vesicles and characterization of their content for various proteins that is not limited by available antibodies.

This is a summary report of clinical and regulatory issues discussed at the 2018 NINDS workshop, entitled "Accelerating Therapies for Antiepileptogenesis and Disease Modification". The intent of the workshop was to optimize and accelerate development of therapies for anti-epileptogenesis (AEG) and disease modification in the epilepsies. The working group discussed nomenclature for antiepileptogenic therapies, subdividing them into antiepileptogenic therapies" and "disease modifying therapies", both of which are urgently needed. We use the example of traumatic brain injury to explain issues and complexities in designing a trial for disease preventing antiepileptogenic therapies, including identifying timing of intervention, selecting the appropriate dose, and the need for biomarkers. We discuss the recent trials of vigabatrin to prevent onset and modify epilepsy outcome in children with tuberous sclerosis (Epistop and PreVeNT). We describe a potential approach to a disease modification trial in adults, using patients with Temporal Lobe Epilepsy. Finally, we discuss regulatory hurdles for antiepileptogenesis and disease modifying trials.

OBJECTIVE:Pain specialists treat patients with headache and interface with those who use opioids more so than neurologists and headache specialists. We assessed headache medicine knowledge and needs of pain specialists. DESIGN/SETTING/METHODS:Cross-sectional online survey. SUBJECTS/METHODS:Members of the American Academy of Pain Medicine. METHODS:Survey was based on a prior survey on primary care providers' knowledge and needs and was iteratively updated by four headache specialists, two with pain medicine affiliations. RESULTS:Of the 105 respondents, 71.4% were physicians, 34.3% were women, and they averaged 20.0 ± 13.6 years in practice. The most common specialty was anesthesia (36.1%, n = 35/97) followed by neurology (14.4%, n = 14/97). About half of providers (55.7%, n = 34/61 and 53.3%, n = 32/60) were familiar with the American Academy of Neurology Guidelines for pharmacological migraine prevention and the Choosing Wisely Campaign recommendations for limiting neuroimaging and opioids. Less than half of all providers (39.7%, n = 23/58) were familiar with the American Headache Society guidelines for emergency management of migraine. Providers were aware of Level A evidence-based nonpharmacological therapies, with over three-fourths recognizing cognitive behavioral therapy (80.7%, n = 50/62) and biofeedback (75.8%, n = 47/62) as evidence-based interventions. About 80% of providers (n = 50/64) estimate making migraine diagnoses in ≤ 50% of their patients with headache. Providers consider starting preventive headache therapy at 7.1 ± 3.9 days/month and report referring 34.3%±34.2% of patients to behavioral interventions. CONCLUSIONS:Dissemination and implementation of headache guidelines is needed for pain medicine specialists. Providers may need help diagnosing migraine based on currently accepted guidelines and referring for evidence-based behavioral therapies.

Traumatic brain injury (TBI) is one of the main causes of death worldwide. It is a complex injury that influences cellular physiology, causes neuronal cell death, and affects molecular pathways in the brain. This in turn can result in sensory, motor, and behavioral alterations that deeply impact the quality of life. Repetitive mild TBI can progress into chronic traumatic encephalopathy (CTE), a neurodegenerative condition linked to severe behavioral changes. While current animal models of TBI and CTE such as rodents, are useful to explore affected pathways, clinical findings therein have rarely translated into clinical applications, possibly because of the many morphofunctional differences between the model animals and humans. It is therefore important to complement these studies with alternative animal models that may better replicate the individuality of human TBI. Comparative studies in animals with naturally evolved brain protection such as bighorn sheep, woodpeckers, and whales, may provide preventive applications in humans. The advantages of an in-depth study of these unconventional animals are threefold. First, to increase knowledge of the often-understudied species in question; second, to improve common animal models based on the study of their extreme counterparts; and finally, to tap into a source of biological inspiration for comparative studies and translational applications in humans.