Digital measurement of SARS-CoV-2 transmission risk from 7 million contacts.

How likely is it to become infected by SARS-CoV-2 after being exposed? Almost everyone wondered about this question during the COVID-19 pandemic. Contact-tracing apps1,2 recorded measurements of proximity3 and duration between nearby smartphones. Contacts-individuals exposed to confirmed cases-were notified according to public health policies such as the 2 m, 15 min guideline4,5, despite limited evidence supporting this threshold. Here we analysed 7 million contacts notified by the National Health Service COVID-19 app6,7 in England and Wales to infer how app measurements translated to actual transmissions. Empirical metrics and statistical modelling showed a strong relation between app-computed risk scores and actual transmission probability. Longer exposures at greater distances had risk similar to that of shorter exposures at closer distances. The probability of transmission confirmed by a reported positive test increased initially linearly with duration of exposure (1.1% per hour) and continued increasing over several days. Whereas most exposures were short (median 0.7 h, interquartile range 0.4-1.6), transmissions typically resulted from exposures lasting between 1 h and several days (median 6 h, interquartile range 1.4-28). Households accounted for about 6% of contacts but 40% of transmissions. With sufficient preparation, privacy-preserving yet precise analyses of risk that would inform public health measures, based on digital contact tracing, could be performed within weeks of the emergence of a new pathogen.

Clinical Features and the Use of Three-Dimensional Imaging for Unilateral Lambdoid Synostosis.

INTRODUCTION: True isolated lambdoid craniosynostosis is rare. It requires corrective surgery to prevent intracranial pressure and aesthetic stigma by significant dyscrania. We summarize our case series for lambdoid craniosynostosis outlining the pathophysiology, clinical findings and surgical approaches and outcomes. METHODOLOGY: A retrospective analysis of our data from 2010 to 2020 summarized our cases of true lambdoid synostosis. We have used the medical notes and the radiological findings from computed tomography scans to summarize a case series of isolated lambdoid synostosis. RESULTS: Our case series demonstrated 7 patients with true isolated lambdoid craniosynostosis. In most cases surgical intervention in the form of posterior cranial vault remodeling utilizing a bandeau, based on occipital advancement techniques, has demonstrated the most consistently favorable aesthetic outcome. CONCLUSIONS: Surgical referral to a craniofacial center should be sought early in difficult to diagnose cases. Although rare, surgical intervention is indicated to correct potentially increased intracranial pressure and to ameliorate cranial dyscrania.

A Simple Bedside Technique for Quantifying Volumetric Defects Prior to Hydroxyapatite Cranioplasty.

Contour irregularities following pediatric craniofacial surgery are common. Hydroxyapatite cranioplasty is a successful technique for optimizing the aesthetic outcome in these patients. We describe a simple technique that can be carried out at the bedside to calculate the volume of hydroxyapatite needed and therefore optimize the preoperative planning for hydroxyapatite cranioplasty.

Spinal cord anomalies in children with anorectal malformations: Ultrasound is a good screening test.

PURPOSE: The purpose of this study is to correlate spinal ultrasound (US) and magnetic resonance imaging (MRI) findings in patients with anorectal malformations (ARMs). METHODS: A retrospective analysis of records was performed for children with ARM presenting to two major pediatric hospitals between 2009 and 2017. The primary outcome analyzed was detection of spinal cord anomalies. Spinal US was performed up to 4 months and MRI within the first year of life. The conus medullaris was considered normal if it had a tapering contour and terminated at or above the Lumbar 2-3 disk space. RESULTS: One hundred ninety-three patients with ARM presented during the study period with a slight male preponderance (108, 56%). Spinal imaging was performed in 157(82%) - 137(87%) had US, 64(41%) had MRI and 44 (28%) had both. Of the 44 who had both; US was abnormal in 25 children-confirmed by MRI in 20 (80%). US was normal in 17 children- MRI showed a filum cyst in 1 and a lipoma in 2 children and was inconclusive in 2 children (p<0.001). All who required surgery except one child, were reported on spinal US to have a low lying cord, borderline low cord or tethered cord (p<.05). No child who was reported to have a normal spinal US required de-tethering at a later stage. Spinal US had an overall sensitivity of 91% and specificity of 75% compared to MRI for detecting spinal cord anomalies in children with ARM CONCLUSIONS: Spinal US performed in a tertiary pediatric imaging department was a good screening test for spinal cord anomalies in children with ARM. The finding of a low, borderline low or tethered cord on US mandates an MRI to confirm the findings and correlates with the need for operative correction of spinal cord tethering. STUDY TYPE: Clinical research paper. LEVEL OF EVIDENCE: 2.

Australian children undergoing selective dorsal rhizotomy: protocol for a national registry of multidimensional outcomes.

INTRODUCTION: Selective dorsal rhizotomy (SDR) is a neurosurgical intervention intended to permanently reduce spasticity in the lower limbs and improve mobility in selected children with cerebral palsy (CP). Despite SDR having been performed worldwide for the past 30 years, there is moderate quality of evidence that SDR is effective in reducing spasticity with low to very low evidence of its effectiveness in improving gait, function and participation, using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system. Published studies have described outcomes for groups that differ in selection, surgical technique and postoperative rehabilitation making it difficult for clinicians to use this information to advise families on best management. There is substantial community interest in SDR. A small number of children with CP undergo SDR in Australia each year and some families seek the intervention at international sites. Capturing clinical outcomes and adverse event (AE) data for Australian children undergoing SDR will provide clinicians with information to help guide families considering SDR. METHODS AND ANALYSIS: The Australian SDR Research Registry is a national registry of multidimensional outcomes for Australian children undergoing SDR in an Australian or overseas centre. Data will be collected for up to 10 years following the surgery, to include surgery and admission details, surgical and long-term AEs, and outcome measures across the body structure and functions, activity and participation domains of the International Classification of Functioning, Disability and Health. Data will be collected at baseline, during inpatient admission and at 1, 2, 5 and 10 years post. The aim of collecting these data is to improve understanding of short-, medium- and long-term outcomes and adverse effects of the intervention. ETHICS AND DISSEMINATION: This study was approved by the individual Human Research and Ethics committees at the five Australian tertiary hospitals involved. Results will be disseminated via peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: ACTRN12618000985280; Pre-results.

Trial of life: Well infants presenting more than 24 h after head injury with a scalp haematoma: A 10-year review.

AIM: To review the investigation, patterns of injury and short-term outcomes of infants younger than 12 months of age who presented more than 24 h after head injury with an isolated scalp haematoma. METHODS: A retrospective chart review of infants who presented with a head injury to the emergency department of a major paediatric hospital between 2006 and 2016. Patients were included if they presented more than 24 h after the injury, were clinically well and had a documented scalp haematoma. Charts were abstracted using a standardised instrument to yield patient characteristics, mechanism of injury, imaging performed, identified injuries and patient outcome. RESULTS: A total of 2433 records were reviewed, with 157 included in the study. The mean age was 7.5 months (standard deviation 2.6). Of the patients, 14 had a documented palpable skull fracture; 43 patients had a skull X-ray reported as a fracture; 13 patients had cranial ultrasounds with 3 reported as having a fracture; 124 patients had computed tomography head imaging, with 112 demonstrating a fracture; and 52 patients had acute intracranial abnormalities. There were nine unplanned representations (5.7%). No patients required any neurosurgical intervention. CONCLUSIONS: Infants presenting after 24 h with isolated scalp haematomas had good short-term outcomes despite a high prevalence of underlying injury on imaging. Expectant management, rather than imaging, may be a valid approach in this patient population. However, some of these injuries may have been the result of inflicted injury, and all of these patients require a robust assessment regardless of the decision to use a computed tomography scan.

Unilateral Pterional Polycraniosynostosis Treated with Craniectomy and Helmet Therapy.

Craniosynostosis is a condition in which one or more of the cranial sutures have fused prematurely, affecting the growth pattern and contours of the infant skull. The pterion is the junction of temporal, frontal, parietal, and sphenoid bones of the skull. We present a case of unilateral pterional craniosynostosis, which was treated with strip craniectomy and helmet therapy.

Spinal cord detethering procedures in children: a 5 year retrospective cohort study of the early post-operative course.

Tethered spinal cord can cause neurological, orthopaedic and sphincteric problems in children and detethering surgery may prevent or reverse these problems. This 5 year retrospective cohort study aimed to review our experience of detethering surgery at The Children's Hospital at Westmead, Sydney, Australia, particularly examining the early post-operative complications of this procedure. Between 2007 and 2012, 61 children underwent 63 detethering procedures. The median age at detethering surgery was 1.4 years old (interquartile range: 0.7-5.6 years). Fifty-five children (90.1%) had lumbosacral procedures, 31 (50.8%) were asymptomatic from tethering, 11 (18.0%) had motor or gait disturbance, 11 (18.0%) sphincteric disturbance, eight (13.1%) lower limb orthopaedic deformities, eight (13.1%) scoliosis, six (9.8%) back or leg pain and two (3.3%) sensory disturbance. The most common tethering pathologies were spinal lipomas in 32 children (52.5%), filum abnormalities in 23 (37.7%), dorsal sinus tracts in eight (13.1%) and diastematomyelia in seven (11.5%). Twenty-six children (42.6%) had either a syrinx or central canal dilatation preoperatively. The most common complications were wound infection and cerebrospinal fluid leak. Six children (9.8%) required reoperation for wound issues and two patients (3.3%) required subsequent reoperation for cord retethering during the study period. There were no deaths and no new neurological deficits. Of the children with the above preoperative deficits, 26.7% were documented to have improvement or resolution of their symptoms post-operatively. The highest rate of improvement occurred in children with motor or gait disturbance (36.4%) or sphincteric disturbance (27.3%).

miR-124a is frequently down-regulated in glioblastoma and is involved in migration and invasion.

Glioblastoma (GBM) represents a formidable clinical challenge for both patients and treating physicians. Due to better local treatments and prolonged patient survival, remote recurrences are increasingly observed, underpinning the importance of targeting tumour migration and attachment. Aberrant expression of microRNA (miRNA) is commonly associated with cancer and loss of miR-124a has previously been implicated to function as a tumour suppressor. The assessment of miR-124a in clinical specimens has been limited and a potential role in migration and invasion has been unexplored until now. We measured the expression levels of mature miR-124a in a retrospective series of 119 cases of histologically confirmed GBM and found its expression was markedly lower in over 80% of the GBM clinical specimens compared to normal brain tissue. The level of reduction in the clinical cohort varied significantly and patients with lower than the average miR-124a expression levels displayed shorter survival times. Endogenous miR-124a expression and the protein expression of three of its targets; IQ motif containing GTPase activating protein 1 (IQGAP1), laminin γ1 (LAMC1) and integrin ß1 (ITGB1) were significantly reciprocally associated in the majority of the clinical cases. We confirmed this association in our in vitro model. Functionally, the ectopic expression of mature miR-124a in a GBM cell line resulted in significant inhibition of migration and invasion, demonstrating a role for miR-124a in promoting tumour invasiveness. Our results suggest that miR-124a may play a role in GBM migration, and that targeted delivery of miR-124a may be a novel inhibitor of GBM invasion.

Schwannomatosis, sporadic schwannomatosis, and familial schwannomatosis: a surgical series with long-term follow-up. Clinical article.

OBJECT: The aim of this study was to provide disease-specific information about schwannomatosis in its different forms and to present 2 particular cases of malignant schwannomas in the context of familial schwannomatosis (FS). METHODS: The authors analyzed patients with pathologically defined schwannomas and identified those with varied forms of schwannomatosis. Each case was retrospectively analyzed for patient sex and age, number of operations and tumors excised, symptoms, location and size of tumors, extent of resection, nerve function pre- and postoperatively, complications, other nonsurgically treated tumors, malignancy, results of brain MR imaging, and follow-up data. RESULTS: One hundred fifty-eight patients underwent the excision of 216 schwannomas. One hundred forty-two patients presented with solitary schwannomas, 2 had neurofibromatosis Type 2 (NF2), and 14 presented with schwannomatosis. The average follow-up was 52 months. Six individuals had sporadic schwannomatosis, whereas 8 had the familial form of the disease. These 14 patients had an average age of 28.3 years at the time of disease onset (median 27.5 years) and 35.4 years at the time of the first operation (median 37 years) Thirteen of the 14 patients with schwannomatosis experienced pain as the first symptom. Eight (57%) of the 14 patients presented with at least 1 tumor in the spinal canal or attached to the spinal nerve roots. Malignant schwannomas developed in 2 patients from the same family during the follow-up. CONCLUSIONS: Patients suffering from schwannomatosis tend to be younger than those presenting with solitary schwannomas. Therefore, individuals presenting at a young age with multiple schwannomas but not meeting the criteria for NF2 should prompt the physician to suspect schwannomatosis. Patients with schwannomatosis who report pain should be exhaustively examined. The spine is affected in the majority of patients, and MR imaging of the spine should be part of the routine evaluation. Rapid enlargement of schwannomas in the context of FS should raise suspicion of malignant transformation.

Post-contrast enhancement as a clinical indicator of prognosis in patients with anaplastic astrocytoma.

Diagnosis of an anaplastic astrocytoma (World Health Organization grade III) is associated with a highly variable prognosis. The identification of clinical markers that allow a more careful delineation of this prognostic spectrum is urgently needed. In this study, we analysed 48 patients with a histological diagnosis of anaplastic astrocytoma and found peritumoral post-gadolinium contrast enhancement to be a clear prognostic marker of poor prognosis. Multivariate analysis also confirmed surgery type, Karnofsky Performance Status score (<70) and increasing age as independent adverse predictors of survival. The survival differences observed in the enhancing and non-enhancing lesions in patients diagnosed with anaplastic astrocytoma supports the existence of a broad anaplastic spectrum of disease, with enhancement being a clinical marker of tumour progression along this spectrum.