Idiopathic Neonatal Subpial Hemorrhage with Underlying Cerebral Infarct: Imaging Features and Clinical Outcome

BACKGROUND AND PURPOSE

Neonatal subpial hemorrhage with underlying cerebral infarct is a previously described but poorly understood clinicoradiographic syndrome. We sought to further characterize the cranial ultrasound and MR imaging characteristics and associated outcomes of this condition across the full range of gestational ages, including extreme and very preterm neonates.

MATERIALS AND METHODS

This was a single tertiary pediatric center retrospective case series. Brain MR imaging and cranial ultrasound of neonates with subpial hemorrhage with underlying cerebral infarct were identified from a population-based radiology registry (2006-2020). Original images were reviewed by 2 neuroradiologists blinded to history and outcome. Clinical presentation, course, and outcome at >12 months were abstracted from medical records. The diagnostic utility of cranial ultrasound was compared with that of MR imaging.

RESULTS

Sixteen patients were included (median gestational age, 36.5 weeks; range, 27-41 weeks; 31% premature). MR images were obtained acutely at the time of presentation between days 0 and 9 of life. On T2WI and DWI, a consistent presence of a hypointense subpial bleed and an underlying hyperintense cerebral cortex were recognized, which created a distinct MR imaging pattern resembling the yin-yang symbol. Findings of all the MRAs and MRVs were normal. Cranial ultrasound detected 6 of 7 MR imaging lesions with sonographic features correlating well with MR imaging. The 3 extreme or very preterm neonates did not survive. The remainder survived with relatively mild neurologic deficits.

CONCLUSIONS

Subpial hemorrhage with underlying infarction is a recognizable condition with unique MR imaging and sonographic features. Improved recognition may advance understanding of risk factors and outcomes.

Designing a flexible tool for rapid implementation of brain-computer interfaces (BCI) in game development

Early neurological injury or disease can lead to severe life-long physical impairments, despite normal cognitive function. For such individuals, brain-computer interfaces (BCI) may provide a means to regain access to the world by offering control of systems through directly processing brain patterns. However, current BCI applications are often research driven and consequently seen as uninteresting, particularly for prolonged use and younger BCI-users. To help mitigate this concern, this paper establishes a tool for researchers and game developers alike to rapidly incorporate a BCI control scheme (the P300 oddball response) into a gaming environment. Preliminary results indicate the proposed P300 Dynamic Cube (PDC) asset works in online BCI environments (n=20, healthy adult participants), resulting in median classification accuracy of 75 ± 3.28%. Additionally, the PDC tool can be rapidly adapted for a variety of game designs, evidenced by its incorporation into submissions to the Brain-Computer Interface (BCI) Game Jam 2019 competition. These findings support the PDC as a useful asset in the design and development of BCI-based games.

A Child's Right to Play: Results from the Brain-Computer Interface Game Jam 2019 (Calgary Competition)

Children with severe neurological disabilities may be unable to communicate or interact with their environments, depriving them of their right to play. Brain-computer interfaces (BCI) offer a means for such children to control external devices using only their brain signals, thereby introducing new opportunities for interaction. We organized the first North American BCI Game Jam to incite the development of BCI-compatible games for children. Nine games were submitted by 30 participants across North America. Games were judged by researchers and disabled children currently using BCI. Preliminary results demonstrate variety in game criteria preferences amongst the children who judged the games. The BCI Game Jam demonstrated promising potential for the creation of enjoyable games to suit the individual needs and preferences of children with severe neurological disabilities.

A Case of Transcranial Direct-Current Stimulation for Childhood Stroke Hemiparesis: A Brief Report

Purpose: Survivors of childhood stroke incur lifelong physical disability. Treatment options are limited, however, models of motor reorganization after stroke are revealing cortical targets for neuromodulation. Transcranial direct-current stimulation (tDCS) enhances motor learning and may improve motor recovery in adult stroke, but remains uninvestigated in childhood-onset stroke. Here we documented the feasibility and safety of tDCS in an adolescent with chronic stroke-induced hemiparesis.Materials and methods: Over 10 days, the participant underwent occupational therapy paired with contralesional, primary motor cortex-targeting, cathodal tDCS. Clinical motor outcomes, and safety and tolerability measures were completed.Results: tDCS was well-tolerated with no adverse events. Motor outcomes did not regress post-intervention, with clinically significant changes still evident at 6 months.Conclusions: Application of controlled trials of non-invasive neuromodulation are safe and tolerability in childhood-onset stroke.

Safety and tolerability of transcranial magnetic and direct current stimulation in children: Prospective single center evidence from 3.5 million stimulations

BACKGROUND

Non-invasive brain stimulation is being increasingly used to interrogate neurophysiology and modulate brain function. Despite the high scientific and therapeutic potential of non-invasive brain stimulation, experience in the developing brain has been limited.

OBJECTIVE

To determine the safety and tolerability of non-invasive neurostimulation in children across diverse modalities of stimulation and pediatric populations.

METHODS

A non-invasive brain stimulation program was established in 2008 at our pediatric, academic institution. Multi-disciplinary neurophysiological studies included single- and paired-pulse Transcranial Magnetic Stimulation (TMS) methods. Motor mapping employed robotic TMS. Interventional trials included repetitive TMS (rTMS) and transcranial direct current stimulation (tDCS). Standardized safety and tolerability measures were completed prospectively by all participants.

RESULTS

Over 10 years, 384 children underwent brain stimulation (median 13 years, range 0.8-18.0). Populations included typical development (n = 118), perinatal stroke/cerebral palsy (n = 101), mild traumatic brain injury (n = 121) neuropsychiatric disorders (n = 37), and other (n = 7). No serious adverse events occurred. Drop-outs were rare (<1%). No seizures were reported despite >100 participants having brain injuries and/or epilepsy. Tolerability between single and paired-pulse TMS (542340 stimulations) and rTMS (3.0 million stimulations) was comparable and favourable. TMS-related headache was more common in perinatal stroke (40%) than healthy participants (13%) but was mild and self-limiting. Tolerability improved over time with side-effect frequency decreasing by >50%. Robotic TMS motor mapping was well-tolerated though neck pain was more common than with manual TMS (33% vs 3%). Across 612 tDCS sessions including 92 children, tolerability was favourable with mild itching/tingling reported in 37%.

CONCLUSIONS

Standard non-invasive brain stimulation paradigms are safe and well-tolerated in children and should be considered minimal risk. Advancement of applications in the developing brain are warranted. A new and improved pediatric NIBS safety and tolerability form is included.

Targeting of NAT10 enhances healthspan in a mouse model of human accelerated aging syndrome

Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare, but devastating genetic disease characterized by segmental premature aging, with cardiovascular disease being the main cause of death. Cells from HGPS patients accumulate progerin, a permanently farnesylated, toxic form of Lamin A, disrupting the nuclear shape and chromatin organization, leading to DNA-damage accumulation and senescence. Therapeutic approaches targeting farnesylation or aiming to reduce progerin levels have provided only partial health improvements. Recently, we identified Remodelin, a small-molecule agent that leads to amelioration of HGPS cellular defects through inhibition of the enzyme N-acetyltransferase 10 (NAT10). Here, we show the preclinical data demonstrating that targeting NAT10 in vivo, either via chemical inhibition or genetic depletion, significantly enhances the healthspan in a Lmna G609G HGPS mouse model. Collectively, the data provided here highlights NAT10 as a potential therapeutic target for HGPS.

Effects of transcranial direct-current stimulation on laparoscopic surgical skill acquisition

Background

Changes in medical education may limit opportunities for trainees to gain proficiency in surgical skills. Transcranial direct-current stimulation (tDCS) can augment motor skill learning and may enhance surgical procedural skill acquisition. The aim of this study was to determine the effects of tDCS on simulation-based laparoscopic surgical skill acquisition.

Methods

In this double-blind, sham-controlled randomized trial, participants were randomized to receive 20 min of anodal tDCS or sham stimulation over the dominant primary motor cortex, concurrent with Fundamentals of Laparoscopic Surgery simulation-based training. Primary outcomes of laparoscopic pattern-cutting and peg transfer tasks were scored at baseline, during repeated performance over 1 h, and again at 6 weeks. Intent-to-treat analysis examined the effects of treatment group on skill acquisition and retention.

Results

Of 40 participants, those receiving tDCS achieved higher mean(s.d.) final pattern-cutting scores than participants in the sham group (207·6(30·0) versus 186·0(32·7) respectively; P = 0·022). Scores were unchanged at 6 weeks. Effects on peg transfer scores were not significantly different (210·2(23·5) in the tDCS group versus 201·7(18·1) in the sham group; P = 0·111); the proportion achieving predetermined proficiency levels was higher for tDCS than for sham stimulation. Procedures were well tolerated with no serious adverse events and no decreases in motor measures.

Conclusion

The addition of tDCS to laparoscopic surgical training may enhance skill acquisition. Trials of additional skills and translation to non-simulated performance are required to determine the potential value in medical education and impact on patient outcomes. Registration number: NCT02756052 (https://clinicaltrials.gov/).

Clinical and Imaging Characteristics of Arteriopathy Subtypes in Children with Arterial Ischemic Stroke: Results of the VIPS Study

BACKGROUND AND PURPOSE

Childhood arteriopathies are rare but heterogenous, and difficult to diagnose and classify, especially by nonexperts. We quantified clinical and imaging characteristics associated with childhood arteriopathy subtypes to facilitate their diagnosis and classification in research and clinical settings.

MATERIALS AND METHODS

The Vascular Effects of Infection in Pediatric Stroke (VIPS) study prospectively enrolled 355 children with arterial ischemic stroke (2010-2014). A central team of experts reviewed all data to diagnose childhood arteriopathy and classify subtypes, including arterial dissection and focal cerebral arteriopathy-inflammatory type, which includes transient cerebral arteriopathy, Moyamoya disease, and diffuse/multifocal vasculitis. Only children whose stroke etiology could be conclusively diagnosed were included in these analyses. We constructed logistic regression models to identify characteristics associated with each arteriopathy subtype.

RESULTS

Among 127 children with definite arteriopathy, the arteriopathy subtype could not be classified in 18 (14%). Moyamoya disease (n = 34) occurred mostly in children younger than 8 years of age; focal cerebral arteriopathy-inflammatory type (n = 25), in children 8-15 years of age; and dissection (n = 26), at all ages. Vertigo at stroke presentation was common in dissection. Dissection affected the cervical arteries, while Moyamoya disease involved the supraclinoid internal carotid arteries. A banded appearance of the M1 segment of the middle cerebral artery was pathognomonic of focal cerebral arteriopathy-inflammatory type but was present in <25% of patients with focal cerebral arteriopathy-inflammatory type; a small lenticulostriate distribution infarct was a more common predictor of focal cerebral arteriopathy-inflammatory type, present in 76%. It remained difficult to distinguish focal cerebral arteriopathy-inflammatory type from intracranial dissection of the anterior circulation. We observed only secondary forms of diffuse/multifocal vasculitis, mostly due to meningitis.

CONCLUSIONS

Childhood arteriopathy subtypes have some typical features that aid diagnosis. Better imaging methods, including vessel wall imaging, are needed for improved classification of focal cerebral arteriopathy of childhood.

Variation in olfactory neuron repertoires is genetically controlled and environmentally modulated

The mouse olfactory sensory neuron (OSN) repertoire is composed of 10 million cells and each expresses one olfactory receptor (OR) gene from a pool of over 1000. Thus, the nose is sub-stratified into more than a thousand OSN subtypes. Here, we employ and validate an RNA-sequencing-based method to quantify the abundance of all OSN subtypes in parallel, and investigate the genetic and environmental factors that contribute to neuronal diversity. We find that the OSN subtype distribution is stereotyped in genetically identical mice, but varies extensively between different strains. Further, we identify cis-acting genetic variation as the greatest component influencing OSN composition and demonstrate independence from OR function. However, we show that olfactory stimulation with particular odorants results in modulation of dozens of OSN subtypes in a subtle but reproducible, specific and time-dependent manner. Together, these mechanisms generate a highly individualized olfactory sensory system by promoting neuronal diversity.

DOI:http://dx.doi.org/10.7554/eLife.21476.001

Smells are simply chemicals in the air that are recognized by nerves in our nose. Each nerve has a receptor that can identify a limited number of chemicals, and the nerve then relays this information to the brain. Animals have hundreds to thousands of different types of these nerves meaning that they can detect a wide array of smells.

Smell receptors are proteins, and the genes that encode these proteins can be very different in two unrelated people. This could partly explain, for example, why some people find certain odors intense and unpleasant while others do not. However, having different genes for smell receptors does not by itself completely explain why some people are more sensitive than others to particular smells. The amounts of each nerve type in the nose might also differ between people and have an effect, but to date it has not been possible to accurately count them all.

Ibarra-Soria et al. have now devised a new method to essentially count the number of each nerve type in the noses of mice from different breeds. The method makes use of a technique called RNA-sequencing, which can reveal which genes are active at any one time, and thus show how many nerves are producing each type of smell receptor. Ibarra-Soria et al. learned that different breeds of mice had remarkably different compositions of nerves in their noses. Further analysis revealed that this was due to changes to the DNA code near to the genes that encode the smell receptor.

Next, Ibarra-Soria et al. sought to find out how the amount of each nerve type is controlled by giving mice water with different smells for weeks and looking how this affected their noses. These experiments revealed that a small number of the nerve types became more or less common after exposure to a smell. The altered nerves were directly involved in recognizing the smells, proving that the very act of smelling can change the make-up of nerves in a mouse’s nose.

These results confirm that the diversity in the nose of each individual is not only dictated by the types of receptors found in there, but also by the number of each nerve type. The next challenge is to understand better how these differences change the way people perceive smells.

DOI:http://dx.doi.org/10.7554/eLife.21476.002

What is the potential for context aware communication aids?

Use of voice output communication aids (VOCAs) can be a very effective strategy to assist people with speech impairments in communicating. Despite this, people who use communication aids often express frustration with VOCAs-desiring devices that are simpler, quicker and more effective to use. Whilst it is not possible to resolve all these issues with technology, it is argued that significant progress can be made. The use of contextual information is one development that could improve the simplicity and effectiveness of communication aid design. Improving the effectiveness of communication aids, including through the use of context support, is a goal of the NIHR Devices for Dignity Assistive Technology Theme. This discussion paper examines the potential for creating 'context aware' communication aids. Three projects in which the authors have been involved are described to illustrate different approaches to the use of contextual information.

Seizure response dogs: evaluation of a formal training program

Evidence supporting seizure-related behaviors in dogs is emerging. The methods of seizure response dog (SRD) training programs are unstudied. A standardized survey was retrospectively applied to graduates of a large SRD program. Subjective changes in quality of life (QOL) parameters were explored. Data were captured on animal characteristics, training methods, response and alerting behaviors, effects on seizure frequency, and accuracy of epilepsy diagnosis. Twenty-two patients (88%) participated (median age=34, range=12-66, 73% female). Most had childhood-onset epilepsy (87%) that was refractory with averages of 36 seizures/month and 4.8 medications failed. All had neurologist-confirmed epilepsy, most being symptomatic partial (64%). SRD behaviors were reliable, including emergency response system activation in 27%. All reported SRD-related QOL improvements (major 82%, moderate 18%) across multiple parameters. Spontaneous alerting behavior developed in 59%. That SRD programs may select genuine epilepsy patients, instill valuable assistance skills, and generate meaningful QOL improvements supports further seizure dog research.

Role of maxi-K+ channels in endothelin-induced vasoconstriction of mesenteric and submucosal arterioles

The action of endothelin in small intestinal resistance vessels of the guinea pig was studied by examining submucosal arteriole vasoactivity in vitro and electrical properties of mesenteric arteriole smooth muscle cells. Endothelin-1 (ET-1) constricted submucosal arterioles with a half-maximal effective concentration of 170 pM. ET-3 caused detectable constriction with a minimum of 20 nM. The ET-1 response was prolonged, with a time to 90% relaxation of 41 +/- 2.8 min after washout. The ETA antagonist BQ-123 (200 nM) decreased the sensitivity to ET-1 approximately 40-fold. Arterioles preconstricted with prostaglandin F2 alpha did not relax when superfused with ET-1, ET-3, or an ETB agonist, IRL-1620, and pretreatment with the nitric oxide synthase inhibitor NG-monomethyl-L-arginine was ineffective in countering ET-1-induced constriction, indicating the absence of functional ETB receptors. Resting membrane potential in isolated cells was characterized by transient hyperpolarizing spikes (THs). ET-1 (20 nM) increased TH frequency and caused the emergence of a larger amplitude population. Under voltage clamp, spontaneous transient outward currents (STOCs) were seen that reversed at the K+ equilibrium potential. ET-1 increased STOC frequency and amplitude. Iberiotoxin (IBTX; 200 nM), a maxi-K+ channel antagonist, blocked the ET-1-induced THs and reduced STOC activity. IBTX or tetraethylammonium increased the rate and extent of ET-1-induced arteriole constriction. We suggest that ET-1-induced vasoactivity of ileal resistance arterioles involves ETA receptor-mediated early activation of maxi-K+ channels that serves to counter strong constriction.