Llewellyn Padayachy

Clinical characteristics and neurodevelopmental outcomes of children with tuberculous meningitis and hydrocephalus

Tuberculous meningitis (TBM) is a lethal and commonly occurring form of extra‐pulmonary tuberculosis in children, often complicated by hydrocephalus which worsens outcome. Despite high mortality and morbidity, little data on the impact on neurodevelopment exists. We examined the clinical characteristics, and clinical and neurodevelopmental outcomes of TBM and hydrocephalus.

Non-invasive intracranial pressure assessment

Assessing intracranial pressure (ICP) remains a cornerstone in neurosurgical care. Invasive techniques for monitoring ICP remain the gold standard. The need for a reliable, safe and reproducible technique to non-invasively assess ICP in the context of early screening and in the neurocritical care environment is obvious. Numerous techniques have been described with several novel advances. While none of the currently available techniques appear independently accurate enough to quantify raised ICP, there is some promising work being undertaken.

Pulsatile Dynamics of the Optic Nerve Sheath and Intracranial Pressure: An Exploratory In Vivo Investigation.

BACKGROUND: Raised intracranial pressure (ICP) may lead to increased stiffness of the optic nerve sheath (ONS). OBJECTIVE: To develop a method for analyzing ONS dynamics from transorbital ultrasound and investigate a potential difference between patients with raised ICP vs normal ICP. METHODS: We retrospectively analyzed data from 16 patients (≤12 years old) for whom ultrasound image sequences of the ONS had been acquired from both eyes just before invasive measurement of ICP. Eight patients had an ICP ≥20 mm Hg. The transverse motion on each side of the ONS was estimated from ultrasound, and Fourier analysis was used to extract the magnitude of the displacement corresponding to the heart rate. By calculating the normalized absolute difference between the displacements on each side of the ONS, a measure of ONS deformation was obtained. This parameter was referred to as the deformability index. According to our hypothesis, because deformability is inversely related to stiffness, we expected this parameter to be lower for ICP ≥20 mm Hg compared with ICP <20 mm Hg. The one-sided Mann-Whitney U test was used for statistical comparison. RESULTS: The deformability index was significantly lower in the group with ICP ≥20 mm Hg (median value 0.11 vs 0.24; P = .002). CONCLUSION: We present a method for assessment of ONS pulsatile dynamics using transorbital ultrasound imaging. A significant difference was noted between the patient groups, indicating that deformability of the ONS may be relevant as a noninvasive marker of raised ICP. The clinical implications are promising and should be investigated in future clinical studies. ABBREVIATIONS: AUC, area under curve ICP, intracranial pressure ONS, optic nerve sheath ONSD, optic nerve sheath diameter ROC, receiver operating characteristic

Spina bifida: a multidisciplinary perspective on a many-faceted condition.

Open spina bifida or myelomeningocele (SBM) is the most common birth defect involving the central nervous system, second only in incidence to congenital cardiac disease. Outcomes in this disorder were poor until the mid-20th century, when modern neurosurgical techniques (closing the lesion and treating hydrocephalus) and treatment for the neuropathic bladder addressed the major causes of mortality, although SBM may still be poorly treated in the developing world. Initial management - or mismanagement - has a profound impact on survival and long-term quality of life.

Intraoperative ultrasound-guidance in neurosurgery.

ince the first recorded use of the “ultrasonoscope” for localizing subcortical intracerebral neoplasms in postmorS tem specimens in 1950 (4), technological advances in ultrasound have seen a transformation from poor-quality, A-mode wave forms to superb-quality, real-time images in 2 (2D) and 3 (3D) dimensions. As a result, intraoperative ultrasonography (IOUS) has undergone remarkable development, particularly in the last 2 decades.

Neuroschistosomiasis due to schistosoma haematobium presenting as spinal cord tumor

Schistosomiasis is rarely encountered in the United States, but immigration and travel to endemic areas make it important to know its various presentations to improve diagnosis and treatment. We present our experience with a child with Schistosoma haematobium pseudotumor, initially diagnosed as a cord neoplasm.

125 Transorbital Ultrasound Measurement as a Noninvasive Marker of Intracranial Pressure.

INTRODUCTION Reliable assessment of intracranial pressure (ICP) remains crucial in managing neurosurgical conditions in children. The present study examined the relationship between transorbital ultrasound measurement of the optic nerve sheath diameter (ONSD) and invasively measured ICP in children. METHODS This was a prospective, observational study comparing ONSD measurement with invasive ICP measurement. All patients were under general anesthesia and physiological variables, including systolic and diastolic blood pressure, mean arterial pressure, pulse rate, temperature, respiratory rate, and end-tidal carbon dioxide level, were recorded at the time of ONSD measurement. The ONSD measurements were analyzed for intra- and interobserver variability. The diagnostic accuracy of ONSD measurement for detecting ICP at thresholds of 20, 15, 10, and 5 mm Hg was analyzed, including evaluation of age-related thresholds in children. RESULTS One hundred ninety-six children were evaluated. The median age was 36 months (interquartile range, 8-82). Etiology included, hydrocephalus (52.9%), traumatic brain injury (17.2%), tumor (9.2%), craniosynostosis (9.2%), cystic malformation (6.9%), other (4.6%). ONSD measurement demonstrated good correlation with ICP across the entire patient cohort (r = 0.66, P < .001), but was better in children >1 year or with a closed anterior fontanelle (AF) (r = 0.7, P < .001). The ONSD values with the best diagnostic accuracy for detecting ICP above 20 mm Hg in older children was 5.75 mm, with a sensitivity of 85.9%, specificity of 70.4%, positive predictive value of 77.5%, negative predictive value of 80.9%, and area under the receiver operating characteristic of 0.78. The diagnostic odds ratio was 14.5. Diagnostic testing was performed at ICP thresholds of 15, 10, and 5 mm Hg as well. CONCLUSION Measurement of the ONSD is a sensitive surrogate marker of raised ICP with limited specificity. This relationship was more reliable in older children, particularly when the AF was closed. This study provides the first data supporting the relationship between ONSD measurement and invasively measured ICP at various thresholds.

Optic nerve sheath diameter as criteria for endoscopic third ventriculostomy failure in children

Dear Editor, We appreciate the comments made on our recent paper by Dr. Jimenez-Guerra, and find his enthusiasm for this technique very inspiring. We agree completely with his sentiment regarding the frustration in determining outcome after performing an ETV, especially in children. In response to specific elements in his commentary: The main reason for describing the change in ONSD as a percentage, relates to the individual baseline variation, making recommendations based on absolute change in diameter quite challenging. The benefit of measuring ONSD as a surrogate marker for raised ICP has become more apparent recently, and hopefully as we start to understand more about the expansile nature of the ONS, we will refine the accuracy of this technique, simplify image acquisition and better define its relationship with ICP. While it is quite logical to assume that the reduction in ICP after ETVwould not be as dramatic as it would be after a VPS, as mentioned by Dr. Jimenez-Guerra; I would add that the degree to which the ICP is raised during either procedure has as much of an impact on the change in ONSD as the type of procedure, i.e. higher ICP at treatment would likely lead to a greater change in ONSD after treatment. The fact that ‘60 % of patients experiencing failed procedures’ also had a decrease in ONSD is not really that surprising, given that a failed ETV does not imply that the ICP is the same as during the original procedure, hence the ONS distension, while increased, may well be less than the original value, even though the stoma may not be working optimally. The number of failed procedures in our study was quite small, as acknowledged in the paper, making absolute interpretation in this group quite difficult [1]. The overall potential of change in ONSD as a radiological marker for outcome in ETV, however, was highlighted. With repeated episodes of significantly raised ICP, the ability of the ONS to return to its baseline measurement is likely altered; hence, the elasticity of the ONSmay play a muchmore important role in its ability to distend thanwe currently appreciate. Elasticity of the ONS is a formidable parameter to quantify in vivo, but improved understanding of the extent to which the sheath is stretched would help us better understand the variation in individual diameter readings. Particular factors like previous distension, hysteresis, baseline diameter, age and length of time that ICP is increased for, all therefore act in concert to determine the actual measureable ONSD [2]. The concept of an age-related upper limit of ONSD is certainly intuitive and physiological [3], but as we see more high quality work on this topic emerging in children, particularly comparing ONSD to invasively measured ICP, these absolute, historic values may be challenged somewhat. We certainly agree that ONSD measurement is poised to enjoy a more useful role not only in determining outcome from ETV, but potentially for a number of other conditions relating to raised ICP and its management. There are however specific factors limiting its use, like poor specificity, lack of consensus regarding the optimal ONSD cut-off value and ICP threshold and disparity amongst * Llewellyn C. Padayachy L.Padayachy@uct.ac.za

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.

Infections in the immunocompromised child

Prevention and management of opportunistic infections in children is particularly relevant in an era demonstrating an increased prevalence of immunocompromising conditions. The presence of an unusual organism which results in serious infection in a child should therefore always raise the consideration of immune compromise. The more common opportunistic infections have become easier to recognize in recent times due to improved awareness and more refined diagnostic testing. Targeted treatment is usually followed by long-term prophylactic medication. The impact of these conditions on patient outcome is of clear significance and certainly warrants further discussion.