Faculty Bibliography

Proteogenomics is an increasingly common method for species identification as it allows for rapid and inexpensive interrogation of an unknown organism's proteome-even when the proteome is partially degraded. The proteomic method typically uses tandem mass spectrometry to survey all peptides detectable in a sample that frequently contains hundreds or thousands of proteins. Species identification is based on detection of a small numbers of species-specific peptides. Genetic analysis of proteins by mass spectrometry, however, is a developing field, and the bone proteome, typically consisting of only two proteins, pushes the limits of this technology. Nearly 20% of highly confident spectra from modern human bone samples identify non-human species when searched against a vertebrate database-as would be necessary with a fragment of unknown bone. These non-human peptides are often the result of current limitations in mass spectrometry or algorithm interpretation errors. Consequently, it is difficult to know if a "species-specific" peptide used to identify a sample is actually present in that sample. Here we evaluate the causes of peptide sequence errors and propose an unbiased, probabilistic approach to determine the likelihood that a species is correctly identified from bone without relying on species-specific peptides.

Venous variants and pathologic abnormalities are the most common causes of pulsatile tinnitus. These conditions include causes of turbulence within normally located veins and sinuses, and abnormally enlarged or abnormally located veins in close transmissive proximity to the conductive auditory pathway. Such disorders include pathologic abnormalities of the lateral sinus (transverse sinus stenosis and sigmoid sinus wall anomalies), abnormalities and variants of the emissary veins, and anomalies of the jugular bulb and jugular vein. Despite being the most common causes for pulsatile tinnitus, venous variants and pathologic abnormalities are often overlooked in the workup of pulsatile tinnitus. Such oversights can result in delayed patient care and prolonged patient discomfort. Advances in both cerebrovascular imaging and endovascular techniques allow for improved diagnostic accuracy and an increasing range of endovascular therapeutic options to address pulsatile tinnitus. This review illustrates the venous causes of pulsatile tinnitus and demonstrates the associated endovascular treatment. © RSNA, 2021.

Lacunar stroke is a marker of cerebral small vessel disease and accounts for up to 25% of ischaemic stroke. In this narrative review, we provide an overview of potential lacunar stroke mechanisms and discuss therapeutic implications based on the underlying mechanism. For this paper, we reviewed the literature from important studies (randomised trials, exploratory comparative studies and case series) on lacunar stroke patients with a focus on more recent studies highlighting mechanisms and stroke prevention strategies in patients with lacunar stroke. These studies suggest that lacunar stroke is a heterogeneous disease with various mechanisms, including most commonly lipohyalinosis and less commonly atheromatous disease and cardioembolism, highlighting the importance of a careful review of brain and neurovascular imaging, a cardiac and systemic evaluation. A better understanding of pathomechanisms of neurological deterioration may lead to investigating the utility of novel treatment strategies and optimisation of short-term antithrombotic treatment strategies to reduce the risk of neurological deterioration and prevent long-term disability in patients with lacunar stroke.

BACKGROUND/UNASSIGNED:There are multiple factors that may cause end-of-life conflict in the critical care setting. These include severe illness, family distress, lack of awareness about a patient's wishes, prognostic uncertainty, and the participation of multiple providers in goals-of-care discussions. METHODS/UNASSIGNED:Case report and discussion of the associated ethical issues. RESULTS/UNASSIGNED:We present a case of a patient with a pontine stroke, in which the family struggled with decision-making about goals-of-care, leading to fluctuation in code status from Full Code to Do Not Resuscitate-Comfort Care, then back to Full Code, and finally to Do Not Resuscitate-Do Not Intubate. We discuss factors that contributed to this situation and methods to avoid conflict. Additionally, we review the effects of discord at the end-of-life on patients, families, and the healthcare team. CONCLUSION/UNASSIGNED:It is imperative that healthcare teams proactively collaborate with families to minimize end-of-life conflict by emphasizing decision-making that prioritizes the best interest and autonomy of the patient.

OBJECTIVE:Paroxysmal epileptiform abnormalities on electroencephalography (EEG) are the hallmark of epilepsies, but it is uncertain to what extent epilepsy and background EEG oscillations share neurobiological underpinnings. Here, we aimed to assess the genetic correlation between epilepsy and background EEG oscillations. METHODS:Confounding factors, including the heterogeneous etiology of epilepsies and medication effects, hamper studies on background brain activity in people with epilepsy. To overcome this limitation, we compared genetic data from a genome-wide association study (GWAS) on epilepsy (n = 12 803 people with epilepsy and 24 218 controls) with that from a GWAS on background EEG (n = 8425 subjects without epilepsy), in which background EEG oscillation power was quantified in four different frequency bands: alpha, beta, delta, and theta. We replicated our findings in an independent epilepsy replication dataset (n = 4851 people with epilepsy and 20 428 controls). To assess the genetic overlap between these phenotypes, we performed genetic correlation analyses using linkage disequilibrium score regression, polygenic risk scores, and Mendelian randomization analyses. RESULTS:Our analyses show strong genetic correlations of genetic generalized epilepsy (GGE) with background EEG oscillations, primarily in the beta frequency band. Furthermore, we show that subjects with higher beta and theta polygenic risk scores have a significantly higher risk of having generalized epilepsy. Mendelian randomization analyses suggest a causal effect of GGE genetic liability on beta oscillations. SIGNIFICANCE/CONCLUSIONS:Our results point to shared biological mechanisms underlying background EEG oscillations and the susceptibility for GGE, opening avenues to investigate the clinical utility of background EEG oscillations in the diagnostic workup of epilepsy.

Pediatric-onset multiple sclerosis (POMS), representing approximately 5% of all MS cases, affects the central nervous system during its ongoing development. POMS is most commonly diagnosed during adolescence but can occur in younger children as well. For pediatric patients with MS, it is critical to manage the full impact of the disease and monitor for any effects on school and social functioning. Disease management includes not only disease-modifying therapies but also strategies to optimize wellbeing. We review the interventions with the highest evidence of ability to improve the disease course and quality of life in POMS. High levels of vitamin D and a diet low in saturated fat are associated with lower relapse rates. Exercise ameliorates fatigue and sleep. Behavioral strategies for sleep hygiene and mood regulation can also improve fatigue and perceived health. POMS management should be addressed holistically, including assessing overall symptom burden as well as the psychological and functional impact of the disease.

The neural mechanisms underlying conscious recognition remain unclear, particularly the roles played by the prefrontal cortex, deactivated brain areas and subcortical regions. We investigated neural activity during conscious object recognition using 7 Tesla fMRI while human participants viewed object images presented at liminal contrasts. Here, we show both recognized and unrecognized images recruit widely distributed cortical and subcortical regions; however, recognized images elicit enhanced activation of visual, frontoparietal, and subcortical networks and stronger deactivation of the default-mode network. For recognized images, object category information can be decoded from all of the involved cortical networks but not from subcortical regions. Phase-scrambled images trigger strong involvement of inferior frontal junction, anterior cingulate cortex and default-mode network, implicating these regions in inferential processing under increased uncertainty. Our results indicate that content-specific activity in both activated and deactivated cortical networks and non-content-specific subcortical activity support conscious recognition.

OBJECTIVE:To determine the long-term safety and tolerability profile of M207 in the acute treatment of migraine. BACKGROUND:M207 is an investigational microneedle-based system for intracutaneous delivery of zolmitriptan for the treatment of migraine attacks. Following on the positive results of a Phase 2/3 placebo-controlled efficacy study (ZOTRIP), this study was designed to evaluate the safety of this novel product during repeated use for the treatment of migraine attacks. METHODS:In this 6-12 month open-label, multicenter observational study, participants used an eDiary to record headache symptoms and adverse events at specified intervals up to 48 h following treatment of a qualifying attack with M207 3.8 mg (intracutaneous zolmitriptan). Participants underwent clinical evaluations at specified intervals up to 12 months. RESULTS:Among 335 participants who treated ≥1 migraine attack, 257 completed 6 months and 127 completed 1 year of treatment. The most common reason for withdrawal from the study was a low frequency of reported attacks post randomization. Overall, 5963 migraine attacks were treated. Most participants (96%) experienced at least 1 adverse event, the vast majority of which concerned the application site, and > 95% of which were mild. Fifteen participants (4%) withdrew due to adverse events; 4 withdrew due to 7 application site reactions, 6 of which were mild. Participants achieved pain freedom in 2477/5617 (44%) of attacks, most bothersome symptom freedom in 3315/5330 (62%) of attacks, and pain relief 2 h post-dose in 4552/5617 (81%) of attacks. Sustained pain freedom 2-24 h was seen in 1761/4698 (38%) of attacks, and 2-48 h in 1534/4429 (35%) of attacks. CONCLUSIONS:The majority of participants experienced cutaneous adverse reactions such as application site erythema, swelling, and bleeding, and most reactions were scored as mild. These results are consistent with what was observed in the single migraine attack treatment ZOTRIP trial indicating that M207 is well tolerated in the setting of longer-term repeated use. Efficacy findings were also similar to those in the ZOTRIP trial. TRIAL REGISTRATION/BACKGROUND:Clinicaltrials.gov on September 13, 2017 ( NCT03282227 ).