Ultrasound as a non-invasive diagnostic tool in paediatric neurosurgery : relationship between the optic nerve sheath diameter (ONSD) and intracranial pressure (ICP)

Includes bibliographical referencesBackground: Assessment of intracranial pressure (ICP) is an essential aspect in the management of most neurosurgical conditions in children. While invasive ICP monitoring is considered the criterion standard, the need for a reliable, non-invasive, easy-to-use and accurate method to detect and monitor raised ICP has inspired the development of many useful techniques. The present study examined the relationship between transorbital ultrasound measurement of the optic nerve sheath diameter (ONSD) and invasively measured ICP in children, as well as the influence of relevant physiological and demographic variables on this relationship. Methodology: ONSD measurement was performed using a high frequency, small footprint linear array probe, and prior to invasive ICP measurement. All patients were under general anaesthesia and being mechanically ventilated. Physiological variables including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse rate, temperature, respiratory rate and end tidal carbon dioxide (ETCO2) level were recorded at the time of ONSD measurement. The ONSD measurements were analysed for repeatability, intra- and inter-observer variability as well for correlation between images acquired in different planes and those obtained from either eye. The diagnostic accuracy of ONSD measurement for detecting ICP at different thresholds of 20, 15, 10 and 5 mmHg was analysed. This analysis included evaluation of age-related thresholds for defining different ONSD cut-off values in children. Dynamic image acquisition was performed and analysed to evaluate the relevant pulsatile motion of the ONS as a marker of the sheath stiffness. Results: One hundred and seventy four children undergoing diagnostic or therapeutic surgical procedures were included in this study. ONSD measurement demonstrated good correlation with ICP across the entire patient cohort (r = 0.66, p 1 year or with a closed anterior fontanelle (AF) (r = 0.7, p < 0.001). Age above and below 1 year was found to be an appropriate age threshold for defining two different sets of ONSD cut-off values. The study however, supported using patency of the AF as a stronger clinical marker for describing different ONSD cut-off values in children. The second part of this work described a dynamic technique for analysing the pulsatile motion of the ONS. Analysis of the deformability index (DI) as an indirect marker of ONS stiffness, revealed a statistically significant relationship with ICP (sensitivity of 90%, specificity of 87% for detecting ICP ≥ 20 mmHg). Conclusion: Measurement of the ONSD is a sensitive surrogate marker of raised ICP, but demonstrated poorer specificity. This relationship was more reliable in older children, particularly when the AF was closed. Analysis of the dynamic characteristics of the ONS appeared to provide useful additional information as an independent marker, and may contribute to our overall understanding of ONSD measurement in raised ICP

Non-invasive assessment of ICP in children: advances in ultrasound-based techniques

The assessment of intracranial pressure (ICP) in children with neurological disease remains a cornerstone in their routine management. The quest for a reliable, reproducible and radiation-free non-invasive technique for assessing ICP in children remains somewhat of a holy grail for neurosurgery. This work assesses some of the recent advances in ultrasound-based techniques, addressing both novel processes and modifications aimed at improving the accuracy of existing techniques.acceptedVersio

Perinatal management of spina bifida

The management of patients with myelomeningocele is largely dependent on the timing of the diagnosis, i.e. ante- or postnatally. Antenatal diagnosis can be made using a combination of maternal serum alpha-fetoprotein measurement, fetal ultrasonography and, where necessary, amniocentesis

Preventing the tower from toppling for women in surgery

In a rich qualitative analysis of interviews with women who left surgical training in Australia, Rhea Liang and colleagues report in The Lancet their study that applied insights from feminist and social theories to illuminate how various factors interact to disadvantage women. They persuasively argue that various stresses accumulate like a tower of stacked blocks. Eventually, an individual's tower can reach a height that it will topple in the absence of efforts to stabilise it; often the final toppling precipitator appears relatively minor. Their findings suggest that interventions seeking to improve retention and advancement of women in surgery must address the underlying multiple and constituent factors (blocks) rather than narrowly focus on the ultimate triggers. Ideally, such interventions should not overtly focus on women alone.The NIH, Doris Duke Charitable Foundation, Komen Foundation, Greenwall Foundation, and Blue Cross Blue Shield of Michigan for the Michigan Radiation Oncology Quality Consortium and personal fees from Vizient and Amgen.http://www.thelancet.comhj2020Surger

Optic nerve sheath diameter measured sonographically as non-invasive estimator of intracranial pressure: a systematic review and meta-analysis

Purpose: Although invasive intracranial devices (IIDs) are the gold standard for intracranial pressure (ICP) measurement, ultrasonography of the optic nerve sheath diameter (ONSD) has been suggested as a potential non-invasive ICP estimator. We performed a meta-analysis to evaluate the diagnostic accuracy of sonographic ONSD measurement for assessment of intracranial hypertension (IH) in adult patients. Methods: We searched on electronic databases (MEDLINE/PubMed\uae, Scopus\uae, Web of Science\uae, ScienceDirect\uae, Cochrane Library\uae) until 31 May 2018 for comparative studies that evaluated the efficacy of sonographic ONSD vs. ICP measurement with IID. Data were extracted independently by two authors. We used the QUADAS-2 tool for assessing the risk of bias (RB) of each study. A diagnostic meta-analysis following the bivariate approach and random-effects model was performed. Results: Seven prospective studies (320 patients) were evaluated for IH detection (assumed with ICP &gt; 20&nbsp;mmHg or &gt; 25 cmH2O). The accuracy of included studies ranged from 0.811 (95% CI 0.678\u20120.847) to 0.954 (95% CI 0.853\u20120.983). Three studies were at high RB. No significant heterogeneity was found for the diagnostic odds ratio (DOR), positive likelihood ratio (PLR) and negative likelihood ratio (NLR), with I2&lt; 50% for each parameter. The pooled DOR, PLR and NLR were 67.5 (95% CI 29\u2012135), 5.35 (95% CI 3.76\u20127.53) and 0.088 (95% CI 0.046\u20120.152), respectively. The area under the hierarchical summary receiver-operating characteristic curve (AUHSROC) was 0.938. In the subset of five studies (275 patients) with IH defined for ICP &gt; 20&nbsp;mmHg, the pooled DOR, PLR and NLR were 68.10 (95% CI 26.8\u2012144), 5.18 (95% CI 3.59\u20127.37) and 0.087 (95% CI 0.041\u20120.158), respectively, while the AUHSROC was 0.932. Conclusions: Although the wide 95% CI in our pooled DOR suggests caution, ultrasonographic ONSD may be a potentially useful approach for assessing IH when IIDs are not indicated or available (CRD42018089137, PROSPERO)

Microbiomics in collusion with the nervous system in carcinogenesis : diagnosis, pathogenesis and treatment

The influence of the naturally occurring population of microbes on various human diseases has been a topic of much recent interest. Not surprisingly, continuously growing attention is devoted to the existence of a gut brain axis, where the microbiota present in the gut can affect the nervous system through the release of metabolites, stimulation of the immune system, changing the permeability of the blood–brain barrier or activating the vagus nerves. Many of the methods that stimulate the nervous system can also lead to the development of cancer by manipulating pathways associated with the hallmarks of cancer. Moreover, neurogenesis or the creation of new nervous tissue, is associated with the development and progression of cancer in a similar manner as the blood and lymphatic systems. Finally, microbes can secrete neurotransmitters, which can stimulate cancer growth and development. In this review we discuss the latest evidence that support the importance of microbiota and peripheral nerves in cancer development and dissemination.The South African Medical Research Council (SAMRC).https://www.mdpi.com/journal/microorganismsam2022Surger

Cystic hemispheric medulloepithelioma

Medulloepithelioma is a rare primitive embryonal tumour of the central nervous system which typically occurs in early childhood. The histopathological appearance has been confused with primitive neuroectodermal tumours (PNETs), but medulloepitheliomas have a more aggressive clinical course. Imaging typically demonstrates a well-circumscribed, poorly or non-enhancing solid mass, with cyst formation being infrequent. We report the imaging findings in a case of a cystic hemispheric medulloepithelioma. The importance of considering this diagnosis is discussed in view of the propensity to aggressive recurrence in subtotal resection

Many voices in a choir: tumor-induced neurogenesis and neuronal driven alternative splicing sound like suspects in tumor growth and dissemination

During development, as tissues expand and grow, they require circulatory, lymphatic, and nervous system expansion for proper function and support. Similarly, as tumors arise and develop, they also require the expansion of these systems to support them. While the contribution of blood and lymphatic systems to the development and progression of cancer is well known and is targeted with anticancer drugs, the contribution of the nervous system is less well studied and understood. Recent studies have shown that the interaction between neurons and a tumor are bilateral and promote metastasis on one hand, and the formation of new nerve structures (neoneurogenesis) on the other. Substances such as neurotransmitters and neurotrophins being the main actors in such interplay, it seems reasonable to expect that alternative splicing and the different populations of protein isoforms can affect tumor-derived neurogenesis. Here, we report the different, documented ways in which neurons contribute to the development and progression of cancer and investigate what is currently known regarding cancer-neuronal interaction in several specific cancer types. Furthermore, we discuss the incidence of alternative splicing that have been identified as playing a role in tumor-induced neoneurogenesis, cancer development and progression. Several examples of changes in alternative splicing that give rise to different isoforms in nerve tissue that support cancer progression, growth and development have also been investigated. Finally, we discuss the potential of our knowledge in alternative splicing to improve tumor diagnosis and treatment.The South African Medical Research Council (SA-MRC)http://www.mdpi.com/journal/cancerspm2021SurgeryUrolog

Brain ultrasonography: methodology, basic and advanced principles and clinical applications. A narrative review

Brain ultrasonography can be used to evaluate cerebral anatomy and pathology, as well as cerebral circulation through analysis of blood flow velocities. Transcranial colour-coded duplex sonography is a generally safe, repeatable, non-invasive, bedside technique that has a strong potential in neurocritical care patients in many clinical scenarios, including traumatic brain injury, aneurysmal subarachnoid haemorrhage, hydrocephalus, and the diagnosis of cerebral circulatory arrest. Furthermore, the clinical applications of this technique may extend to different settings, including the general intensive care unit and the emergency department. Its increasing use reflects a growing interest in non-invasive cerebral and systemic assessment. The aim of this manuscript is to provide an overview of the basic and advanced principles underlying brain ultrasonography, and to review the different techniques and different clinical applications of this approach in the monitoring and treatment of critically ill patients

Brain ultrasonography: methodology, basic and advanced principles and clinical applications. A narrative review

Brain ultrasonography can be used to evaluate cerebral anatomy and pathology, as well as cerebral circulation through analysis of blood flow velocities. Transcranial colour-coded duplex sonography is a generally safe, repeatable, non-invasive, bedside technique that has a strong potential in neurocritical care patients in many clinical scenarios, including traumatic brain injury, aneurysmal subarachnoid haemorrhage, hydrocephalus, and the diagnosis of cerebral circulatory arrest. Furthermore, the clinical applications of this technique may extend to different settings, including the general intensive care unit and the emergency department. Its increasing use reflects a growing interest in non-invasive cerebral and systemic assessment. The aim of this manuscript is to provide an overview of the basic and advanced principles underlying brain ultrasonography, and to review the different techniques and different clinical applications of this approach in the monitoring and treatment of critically ill patients