Medullary Tegmental Cap Dysplasia: Fetal and Postnatal Presentations of a Unique Brainstem Malformation

BACKGROUND AND PURPOSE

Medullary tegmental cap dysplasia is a rare brainstem malformation, first described and defined by James Barkovich in his book Pediatric Neuroimaging from 2005 as an anomalous mass protruding from the posterior medullary surface. We describe the neuroimaging, clinical, postmortem, and genetic findings defining this unique malformation.

MATERIALS AND METHODS

This is a multicenter, international, retrospective study. We assessed the patients' medical records, prenatal ultrasounds, MR images, genetic findings, and postmortem results. We reviewed the medical literature for all studies depicting medullary malformations and evaluated cases in which a dorsal medullary protuberance was described.

RESULTS

We collected 13 patients: 3 fetuses and 10 children. The medullary caps had multiple characteristics. Associated brain findings were a rotated position of the medulla, a small and flat pons, cerebellar anomalies, a molar tooth sign, and agenesis of the corpus callosum. Systemic findings included the following: polydactyly, hallux valgus, large ears, and coarse facies. Postmortem analysis in 3 patients revealed that the cap contained either neurons or white matter tracts. We found 8 publications describing a dorsal medullary protuberance in 27 patients. The syndromic diagnosis was Joubert-Boltshauser syndrome in 11 and fibrodysplasia ossificans progressiva in 14 patients.

CONCLUSIONS

This is the first study to describe a series of 13 patients with medullary tegmental cap dysplasia. The cap has different shapes: distinct in Joubert-Boltshauser syndrome and fibrodysplasia ossificans progressive. Due to the variations in the clinical, imaging, and postmortem findings, we conclude that there are multiple etiologies and pathophysiology. We suggest that in some patients, the pathophysiology might be abnormal axonal guidance.

Characterizing Determinants of Near-Road Ambient Air Quality for an Urban Intersection and a Freeway Site

INTRODUCTION

Near-road ambient air pollution concentrations that are affected by vehicle emissions are typically characterized by substantial spatial variability with respect to distance from the roadway and temporal variability based on the time of day, day of week, and season. The goal of this work is to identify variables that explain either temporal or spatial variability based on case studies for a freeway site and an urban intersection site. The key hypothesis is that dispersion modeling of near-road pollutant concentrations could be improved by adding estimates or indices for site-specific explanatory variables, particularly related to traffic. Based on case studies for a freeway site and an urban intersection site, the specific aims of this project are to (1) develop and test regression models that explain variability in traffic-related air pollutant (TRAP) ambient concentration at two near-roadway locations; (2) develop and test refined proxies for land use, traffic, emissions and dispersion; and (3) prioritize inputs according to their ability to explain variability in ambient concentrations to help focus efforts for future data collection and model development.

The key pollutants that are the key focus of this work include nitrogen oxides (NOx), carbon monoxide (CO), black carbon (BC), fine particulate matter (PM2.5; PM ≤ 2.5 μm in aerodynamic diameter), ultrafine particles (UFPs; PM ≤ 0.1 μm in aerodynamic diameter), and ozone (O3). NOx, CO, and BC are tracers of vehicle emissions and dispersion. PM2.5 is influenced by vehicle table emissions and regional sources. UFPs are sensitive to primary vehicle emissions. Secondary particles can form near roadways and on regional scales, influencing both PM2.5 and UFP concentrations. O3 concentrations are influenced by interaction with NOx near the roadway. Nitrogen dioxide (NO2), CO, PM2.5, and O3 are regulated under the National Ambient Air Quality Standards (NAAQS) because of demonstrated health effects. BC and UFPs are of concern for their potential health effects. Therefore, these pollutants are the focus of this work.

METHODS

The methodological approach includes case studies for which variables are identified and assesses their ability to explain either temporal or spatial variability in pollutant ambient concentrations. The case studies include one freeway location and one urban intersection. The case studies address (1) temporal variability at a fixed monitor 10 meters from a freeway; (2) downwind concentrations perpendicular to the same location; (3) variability in 24-hour average pollutant concentrations at five sites near an urban intersection; and (4) spatiotemporal variability along a walking path near that same intersection.

The study boundary encompasses key factors in the continuum from vehicle emissions to near-road exposure concentrations. These factors include land use, transportation infrastructure and traffic control, vehicle mix, vehicle (traffic) flow, on-road emissions, meteorology, transport and evolution (transformation) of primary emissions, and production of secondary pollutants, and their resulting impact on measured concentrations in the near-road environment. We conducted field measurements of land use, traffic, vehicle emissions, and near-road ambient concentrations in the vicinity of two newly installed fixed-site monitors. One is a monitoring station jointly operated by the U.S. Environmental Protection Agency (U.S. EPA) and the North Carolina Department of Environmental Quality (NC DEQ) on I-40 between Airport Boulevard and I-540 in Wake County, North Carolina. The other is a fixed-site monitor for measuring PM2.5 at the North Carolina Central University (NCCU) campus on E. Lawson Street in Durham, North Carolina. We refer to these two locations as the freeway site and the urban site, respectively. We developed statistical models for the freeway and urban sites.

RESULTS

We quantified land use metrics at each site, such as distances to the nearest bus stop. For the freeway site, we quantified lane-by-lane total vehicle count, heavy vehicle (HV) count, and several vehicle-activity indices that account for distance from each lane to the roadside monitor. For the urban site, we quantified vehicle counts for all 12 turning movements through the intersection. At each site, we measured microscale vehicle tailpipe emissions using a portable emission measurement system.

At the freeway site, we measured the spatial gradient of NOx, BC, UFPs, and PM, quantified particle size distributions at selected distances from the roadway and assessed partitioning of particles as a function of evolving volatility. We also quantified fleet-average emission factors for several pollutants.

At the urban site, we measured daily average concentrations of nitric oxide (NO), NOx, O3, and PM2.5 at five sites surrounding the intersection of interest; we also measured high resolution (1-second to 10-second averages) concentrations of O3, PM2.5, and UFPs along a pedestrian transect. At both sites, the Research LINE-source (R-LINE) dispersion model was applied to predict concentration gradients based on the physical dispersion of pollution.

Statistical models were developed for each site for selected pollutants. With variables for local wind direction, heavy-vehicle index, temperature, and day type, the multiple coefficient of determination (R2) was 0.61 for hourly NOx concentrations at the freeway site. An interaction effect of the dispersion model and a real-time traffic index contributed only 24% of the response variance for NOx at the freeway site. Local wind direction, measured near the road, was typically more important than wind direction measured some distance away, and vehicle-activity metrics directly related to actual real-time traffic were important. At the urban site, variability in pollutant concentrations measured for a pedestrian walk-along route was explained primarily by real-time traffic metrics, meteorology, time of day, season, and real-world vehicle tailpipe emissions, depending on the pollutant. The regression models explained most of the variance in measured concentrations for BC, PM, UFPs, NO, and NOx at the freeway site and for UFPs and O3 at the urban site pedestrian transect.

CONCLUSIONS

Among the set of candidate explanatory variables, typically only a few were needed to explain most of the variability in observed ambient concentrations. At the freeway site, the concentration gradients perpendicular to the road were influenced by dilution, season, time of day, and whether the pollutant underwent chemical or physical transformations. The explanatory variables that were useful in explaining temporal variability in measured ambient concentrations, as well as spatial variability at the urban site, were typically localized real-time traffic-volume indices and local wind direction. However, the specific set of useful explanatory variables was site, context (e.g., next to road, quadrants around an intersection, pedestrian transects), and pollutant specific. Among the most novel of the indicators, variability in real-time measured tailpipe exhaust emissions was found to help explain variability in pedestrian transect UFP concentrations. UFP particle counts were very sensitive to real-time traffic indicators at both the freeway and urban sites. Localized site-specific data on traffic and meteorology contributed to explaining variability in ambient concentrations. HV traffic influenced near-road air quality at the freeway site more so than at the urban site. The statistical models typically explained most of the observed variability but were relatively simple. The results here are site-specific and not generalizable, but they are illustrative that near-road air quality can be highly sensitive to localized real-time indicators of traffic and meteorology.

Controlling the parameters of focused ion beam for ultra-precise fabrication of nanostructures

At present, the focused ion beam method is an effective technique for nanoscale profiling of a solid surface and prototyping of micro- and nanoscale structures. The article reveals the results of experimental studies on improving the accuracy and resolution of nanoscale profiling of the surface of solids with a focused ion beam. Investigations of the regularities of the influence of the focused ion beam current, beam dwell time and overlap on the parameters of nanoscale structures and the surface profile have been carried out. The influence of the FIB parameters on the deviation of the structure profile from the specified by the template was estimated. Experimental studies have been carried out to determine the influence of the direction of scanning of the ion beam by the template on the magnitude of the error that occurs when the structure of the graphic template is transferred to the substrate. The optimal relationships between the FIB current and the dimensions of the structures being formed have been determined, thus making it possible to ensure the highest accuracy and rate of formation of nanoscale structures. The results can be used to optimize the choice of the ion-beam milling parameters to achieve the maximum accuracy of reproduction of the given sizes of structures.

Psychometric validation and responder definition of the sleep disturbance numerical rating scale in moderate-to-severe atopic dermatitis

Background

Sleep disturbance (SD) is an important part of the burden of atopic dermatitis (AD), but patient‐reported outcomes that are easy to understand and interpret in the target population have been lacking. A daily, single‐item, self‐reported SD 11‐point numerical rating scale (NRS) was recently developed to assess SD for patients with moderate‐to‐severe AD, but its psychometric properties have not yet been described.

Objectives

To assess the psychometric properties of the SD NRS in patients with moderate‐to‐severe AD.

Methods

The psychometric properties of the SD NRS were assessed using data from a phase IIb clinical trial in 218 adults with moderate‐to‐severe AD.

Results

Test–retest reliability of the SD NRS was substantial to almost perfect (interclass correlation 0·66–1·00) in participants who had stable SD or stable pruritus scores over 1 week. Baseline correlations were moderate to large (r > 0·30) between SD NRS and pruritus or sleep loss scores, but were small (r = −0·11 to 0·17) between SD NRS and EQ‐5D‐3L index and visual analogue scores, Hospital Anxiety and Depression Scale, Scoring Atopic Dermatitis, and Investigator’s Global Assessment. The SD NRS could discriminate groups of participants in the expected direction according to different quality‐of‐life scores but not according to different clinician‐reported disease severity scores. SD NRS scores significantly decreased as sleep loss, itch and quality‐of‐life scores improved. Analysis of meaningful change suggested a 2–5‐point improvement as the initial range of responder definition in the SD NRS score.

Conclusions

The SD NRS is a reliable, valid and responsive measure of SD in adults with moderate‐to‐severe AD.

Whatis already known about this topic?

Sleep disturbance (SD) is a dynamic, multidimensional concept resulting in daytime fatigue and subsequent changes in physical and mental health that vary from day to day.

SD is an important part of the burden of atopic dermatitis, but ways of effectively and reliably measuring it from the patient perspective have been lacking.

A self‐reported, daily, 11‐point SD numerical rating scale (NRS) was recently developed for assessing SD in patients with moderate‐to‐severe atopic dermatitis, and its content validity was previously established.

Whatdoes this study add?

The study showed that the SD NRS is reliable, valid and responsive and can measure day‐to‐day fluctuations in SD related to atopic dermatitis.

The study also established an initial responder definition (i.e. meaningful interpatient change) for the SD NRS score.

Whatare the clinical implications of this work?

The SD NRS is a brief, simple, easy‐to‐interpret and validated patient‐reported global measure for the daily assessment of SD related to atopic dermatitis.

The SD NRS can be used in clinical trials and clinical practice to assess changes in sleep quality in patients with atopic dermatitis.

Plain language summary available online

Left atrial appendage closure in the presence of thrombus: incidence, technique and outcomes

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with left atrial appendage (LAA) thrombus are excluded for LAA occlusion (LAAO) in clinical trials. However, some of them may require this therapy due to repeated thromboembolisms despite accurate anticoagulation. 

Aim

The aim of the study is to describe the prevalence of LAA thrombosis in patients submitted for LAAO in a high-volume center of LAAO procedures, explaining the employed technique and results in this scenario.

Methods

Single-center retrospective analysis including all consecutive patients referred for LAAO.

Results

LAA thrombus was detected by TEE in 8/76 patients referred for LAAO (10.5%). Five of them underwent LAAO despite the presence of thrombus due to clinical conditions. All the procedures were successfully performed with  Amulet devices (Table). The following preventive measures were putting in place during the implants: avoidance of contrast injection into the LAA during the procedure (non-touch technique), TEE measure for device size election; and TEE device deployment guidance with special care to the the sheath orientation and depth enabling a slow and single implant of the device partially released in the LAA before complete implantation at the entrance of the LAA (Figure. A&B: Large LAA thrombus partially occupying the landing zone. C: Thrombus sealed by LAAO device. D&E: Non-touch technique: echo-guided progressive deployment of the LAAO device without thrombus shifting). No cerebral protection devices were used. TEE performed one month after the procedure ruled out the presence of residual thrombi or leaks in all cases. There were no events after a median follow-up of 17.1 months (range: 32.3-1.1)

Conclusion

LAAO in patient with LAA thrombus can be effectively and safely performed, in high-volume centers  and with an accurate technique, under accurate TEE guidance. Abstract Figure. LAA thrombus and occlusion technique

Healthcare professionals and patient information: a fresh look from the new italian law on consent

ABSTRACT

This article discusses the importance of providing patients with adequate information and creating the care relationship, particularly focusing on the role of healthcare professionals in this activity. It examines the main legislative references on this topic at a European level and the new law, No. 219/2017, in Italy on informed consent that serves as a starting point for recalling important legal and ethical principles regarding the information to be provided to patients in the therapeutic relationship.

A-21 Inhibition of Overlearned Verbal Responses and Quantity of Speech Among Age Cohorts

Objective

Off-topic speech (OTS) has been linked with deficits in executive functioning, and specifically inhibition. OTS research has focused primarily on tangentiality, whereas in this study we focused on quantity of speech. The purpose of this study was to investigate the relationship between inhibition of overlearned responses using a Stroop task and quantity of speech.

Method

A college sample of young adults (n = 63; age 18-28) and healthy, community-dwelling older adults (n = 76; age 60-99) completed the Delis-Kaplan Executive Function Systems (D-KEFS) Color-Word Interference Test and provided a verbal sample in which they recounted a procedural memory and an episodic memory. These samples were transcribed and rated for quantity of speech by three independent judges.

Results

Among all participants, longer time to complete color naming (r = -.21, p = .02) and inhibition (r = -.21, p = .01) was associated with lower quantity of speech on procedural memory. Among young adults, longer time to complete inhibition was associated with lower quantity of speech (r = -.26, p = .04). Among older adults, longer time to complete color naming (r = -.32, p = .005), word reading (r = -.27, p = .02), and inhibition (r = -.35, p = .002) was associated with lower quantity of speech. No relationships were found between performance on Stroop conditions and quantity of speech for episodic memory.

Conclusions

Results suggest that among both age cohorts, difficulty inhibiting overlearned verbal responses is associated with lower quantity of speech regarding a procedural memory but not an episodic memory.

A-13 Sustained Attention, Impulsivity, and Tangentiality of Speech Among Young Adults and Older Adults

Objective

Previous research has linked off-topic verbosity (OTV) among older adults with lower performance on neuropsychological tests tapping attention and executive functioning. However, most of this research has utilized relatively brief neurocognitive measures. Continuous performance tests (CPTs) measure sustained attention and impulsivity. The purpose of this study was to investigate relationships between sustained attention, impulsivity, and tangentiality of speech among young adults and older adults.

Method

Young adult college students (age 18-29; n= 61) and healthy, community-dwelling older adults (age 60-99; n = 81) were administered the Conners’ Continuous Performance Test – 3 and provided a sample of speech (one episodic memory and one procedural memory). These speech samples were transcribed and rated for tangentiality by three independent reviewers.

Results

Among all participants, greater tangentiality of speech was associated with omission errors (r = .22, p = .01) but not with commission errors. This same pattern was found among older adults: omission errors (r = .23, p = .04) were associated with greater tangentiality but commission errors were not. Among young adults, these relationships were not statistically significant.

Conclusions

Results suggest that tangentiality of speech is associated with inattentiveness but not impulsivity, and this relationship may be more marked among older adults than young adults. OTV among older adults may stem from difficulty sustaining attention over time rather than diminished capacity for inhibiting impulses.