Toxoplasma gondii infections in pediatric neurosurgery.

Toxoplasma gondii is a parasite that is estimated to infect one-third of the world's population. It is acquired by ingesting contaminated water and food specially undercooked meat, contact with domestic or wild feline feces, and during pregnancy by transplacental transmission.Immunocompetent hosts are usually asymptomatic, and infection will be self-limited, while those patients whose immune system is debilitated by HIV infection, immunosuppressive therapy, long-term steroid treatment, and fetuses infected during gestation will show evidence of systemic activity which is more severe in the central nervous system and eyes due to insufficient immune response caused by their respective blood barriers. Congenital toxoplasmosis has an estimated incidence of 8% in mothers who were seronegative at the beginning of their pregnancy. Infection in the first trimester may result in spontaneous abortion or stillbirth; however, it is estimated that the highest risk for vertical transmission is during the second and third trimesters when blood flow and placenta thickness favor parasitic transmission.Congenital toxoplasmosis can be detected with periodic surveillance in endemic areas, and with appropriate treatment, the risk of vertical transmission can be reduced, and the severity of the disease can be reversed in infected fetuses.While most infected newborns will show no evidence of the disease, those who suffer active intrauterine complications will present with cerebral calcifications in 8-12% of cases, hydrocephalus in 4-30%, and chorioretinitis in 12-15%. Also, seizure disorders, spasticity, and varying degrees of neurocognitive deficits can be found in 12%.Four distinct patterns of hydrocephalus have been described: aqueductal stenosis with lateral and third ventricle dilatation, periforaminal calcifications leading to foramen of Monro stenosis with associated asymmetrical ventricle dilatation, a mix of aqueductal and foramen of Monro stenosis, and overt hydrocephalus without clear evidence of obstruction with predominant dilatation of occipital horns (colpocephaly).While all patients diagnosed with congenital toxoplasmosis should undergo pharmacological treatment, those presenting with hydrocephalus have traditionally been managed with CSF shunting; however, there are reports of at least 50% success when selected cases are treated with endoscopic third ventriculostomy. Successful hydrocephalus management with appropriate treatment leads to better intellectual outcomes.

Case report: CSF hypotension secondary to a free syringo-subarachnoid-peritoneal shunt.

INTRODUCTION: Syringomyelia is present in 40% of pediatric patients with Chiari malformation. Typically treated with posterior fossa decompression, some cases require further intervention such as syrinx shunting. CASE REPORT: We report a 16-year-old female with Chiari type 1 malformation and syringomyelia who underwent posterior fossa decompression and subsequent free syringo-subarachnoid-peritoneal shunting. The patient developed symptoms of CSF overdrainage, and imaging indicated CSF hypotension. A distal catheter ligation temporarily improved symptoms, but eventually, a programmable ventricular shunt was necessary due to shunt dependence. CONCLUSION: This case highlights the rare complication of CSF overdrainage from syrinx shunting and the importance of shunt selection considerations.

Applied deep learning in neurosurgery: identifying cerebrospinal fluid (CSF) shunt systems in hydrocephalus patients.

BACKGROUND: Over the recent decades, the number of different manufacturers and models of cerebrospinal fluid shunt valves constantly increased. Proper identification of shunt valves on X-ray images is crucial to neurosurgeons and radiologists to derive further details of a specific shunt valve, such as opening pressure settings and MR scanning conditions. The main aim of this study is to evaluate the feasibility of an AI-assisted shunt valve detection system. METHODS: The dataset used contains 2070 anonymized images of ten different, commonly used shunt valve types. All images were acquired from skull X-rays or scout CT-images. The images were randomly split into a 80% training and 20% validation set. An implementation in Python with the FastAi library was used to train a convolutional neural network (CNN) using a transfer learning method on a pre-trained model. RESULTS: Overall, our model achieved an F1-score of 99% to predict the correct shunt valve model. F1-scores for individual shunt valves ranged from 92% for the Sophysa Sophy Mini SM8 to 100% for several other models. CONCLUSION: This technology has the potential to automatically detect different shunt valve models in a fast and precise way and may facilitate the identification of an unknown shunt valve on X-ray or CT scout images. The deep learning model we developed could be integrated into PACS systems or standalone mobile applications to enhance clinical workflows.

Acquired Chiari type I malformation: a late and misunderstood supratentorial over-drainage complication.

PURPOSE: Acquired Chiari I malformation is an uncommon but possible late complication of supratentorial shunting in children. This condition can be caused by an abnormal thickening of the cranial vault and consequent reduction of the posterior cranial fossa (PCF) volume especially in children with already a small PCF volume. The management of Acquired Chiari I malformation is very challenging, and several options have been proposed for this condition. These are aimed to expand the PCF volume both through decompression and PCF remodeling in order to relieve symptoms of acquired Chiari I malformation. A cranial vault remodeling or a standard Chiari decompression is two proposed techniques aimed to expand the PCF volume thus relieving symptoms . METHODS: We describe the case of a 16-year-old girl undergone surgical removal of sellar-suprasellar glioneuronal tumor and ventriculo-peritoneal shunting, who developed an acquired symptomatic Chiari type I malformation some years after ventricular-peritoneal shunting. For this condition, she underwent successful standard Chiari decompression with C0-C1 craniectomy and duroplasty. RESULTS: We retrospectively analyzed MRI and CT scan performed during follow-up, in order to evaluate the volume of the posterior cranial fossa and to measure the variation of skull thickness at different periods. MRI and CT scan analysis showed a progressive thickening of the calvaria, in particular of the occipital bone, leading to a progressive reduction of PCF volume with the establishment of acquired Chiari type I malformation. In this case, standard C0-C1 Chiari decompression was effective in restoring PCF volume and relieving symptoms. CONCLUSION: Acquired Chiari I malformation due to chronic overhunting could be a severe and late complication in patient undergone supratentorial shunting. These patients require careful clinical and radiological follow-up to avoid over-drainage. According to our analysis, a careful selection of pediatric patients for supratentorial shunting should be made according to pre-operative PCF volume in order to foresee higher odds of possible late complications from over-drainage.

Noninvasive CSF shunt patency evaluation by superb microvascular imaging.

Occlusion of a ventriculoperitoneal shunt system is a potentially life-threatening complication in patients suffering from hydrocephalus. However, there is no imaging established as standard approach in this acute setting. In the present study, we evaluate the use of superb microvascular imaging for investigation of the patency of ventriculoperitoneal shunt systems. Simulation of low flow rates of cerebrospinal fluid through a small diameter CSF shunt system was performed in a dedicated phantom in order to proof the principle of superb microvascular imaging (SMI) being feasible for the measurement of slow CSF flow through the dedicated CSF shunt system. SMI is able to detect low flow rates in CSF shunt systems effectively and fast. Visualization of a Duplex ultrasound flow and Doppler wave pattern in the VP shunt system after the reservoir has been pressed confirms patency. SMI is an effective method for evaluating CSF shunt patency and diagnosing shunt obstruction. This bears the potential to facilitate evaluation of clinically symptomatic VP shunt patients in an acute setting. Further evaluation of ultrasound flow patterns is granted.

Idiopathic membranous occlusion of the foramen of Monro: an unusual cause of hydrocephalus and headache in adults.

Occlusion of foramen of Monro is an uncommon clinical entity that usually presents in children. Common causes are obstructing mass, infectious etiologies or vascular malformation. Rarely, it may be an idiopathic stricture or membrane. We report a case of idiopathic membranous obstruction of the foramen of Monro in a 45-year-old male with no past medical or surgical history. He presented with new intermittent dull and burning bifrontal severe headache for 2 d, which was alleviated slightly by non-steroidal anti-inflammatory medication. Imaging showed marked dilation of the lateral ventricles with normal third and fourth ventricles. The patient was discharged initially with conservative medical management and close follows up; however, the headache continued to progress and neurosurgical intervention was offered. The patient underwent endoscopic exploration, fenestration of the septum pellucidum, and right ventriculoperitoneal shunt placement. Bilateral membranous obstruction of foramina of Monro and an auto-fenestrated cavum septum pellucidum were identified intraoperatively. The patient reported resolution of headache post-operatively without recurrence on 1-month follow up. This case is unusual in that the patient presented without any known neurologic history or prior intracranial infections. It became apparent at the time of surgery that chronic obstruction of the bilateral foramina with collapse of the third ventricle had developed, and the safest durable treatment for him was septostomy and cerebrospinal fluid (CSF) shunt placement.

Management of Hydrocephalus in Children: Anatomic Imaging Appearances of CSF Shunts and Their Complications.

OBJECTIVE. This article addresses the management of hydrocephalus and the CSF shunts used to treat this entity. CONCLUSION. CSF shunts have a high failure rate. Imaging plays a pivotal role in assessing CSF shunt failure and determining the need for surgical revision. An in-depth knowledge of CSF shunt components, their failure modes, and the corresponding findings on anatomic imaging studies is necessary to ensure timely diagnosis and prevent permanent neurologic damage.

Shunt technology for infants and a lifetime.

The use of cerebrospinal fluid (CSF) shunts remains a fundamental therapeutic modality in the management of hydrocephalus. Nowadays, neurosurgeons have an arsenal of different shunt technologies on their hands, with several companies producing many different configurations of them. The greatest difficulty of treating a child with hydrocephalus is to deal with a brain that will enormously change its size and hydrodynamic conditions and a body that will multiply its height and weight in a short time. Detailed knowledge of the hydrodynamic properties of shunts is mandatory for any neurosurgeon and much more for those taking care of pediatric patients. It is necessary to know that these properties of the valve may influence the evolution of the patient after shunting and it is recognized that a patient physiology-specific valve selection may yield better outcomes and decrease complications. This article provides a summary of the most common available CSF valves and overdrainage control devices, their technology, and possible combinations. The objective is to offer a quick overview of the armamentarium to facilitate the recognition of the implanted device and improve the selection of the most suitable valve for each patient.

Low-pressure CSF shunt malfunction without preceding lumbar puncture treated by epidural blood patch: report of 2 cases.

Low-pressure CSF shunt malfunction is a poorly understood complication of hydrocephalus affecting patients of all ages. Treatment commonly requires external drainage of CSF to subatmospheric pressures for days to weeks in an intensive care setting. The current communication describes the repurposing of an established therapeutic technique, epidural blood patch, for successful initial management in 2 cases of low-pressure shunt malfunction in the absence of a recognized spinal CSF fistula. This technique may shorten length of stay and obviate potential morbidity in the management of what is otherwise a vexatious clinical problem.

Machine learning predicts risk of cerebrospinal fluid shunt failure in children: a study from the hydrocephalus clinical research network.

PURPOSE: While conventional statistical approaches have been used to identify risk factors for cerebrospinal fluid (CSF) shunt failure, these methods may not fully capture the complex contribution of clinical, radiologic, surgical, and shunt-specific variables influencing this outcome. Using prospectively collected data from the Hydrocephalus Clinical Research Network (HCRN) patient registry, we applied machine learning (ML) approaches to create a predictive model of CSF shunt failure. METHODS: Pediatric patients (age < 19 years) undergoing first-time CSF shunt placement at six HCRN centers were included. CSF shunt failure was defined as a composite outcome including requirement for shunt revision, endoscopic third ventriculostomy, or shunt infection within 5 years of initial surgery. Performance of conventional statistical and 4 ML models were compared. RESULTS: Our cohort consisted of 1036 children undergoing CSF shunt placement, of whom 344 (33.2%) experienced shunt failure. Thirty-eight clinical, radiologic, surgical, and shunt-design variables were included in the ML analyses. Of all ML algorithms tested, the artificial neural network (ANN) had the strongest performance with an area under the receiver operator curve (AUC) of 0.71. The ANN had a specificity of 90% and a sensitivity of 68%, meaning that the ANN can effectively rule-in patients most likely to experience CSF shunt failure (i.e., high specificity) and moderately effective as a tool to rule-out patients at high risk of CSF shunt failure (i.e., moderately sensitive). The ANN was independently validated in 155 patients (prospectively collected, retrospectively analyzed). CONCLUSION: These data suggest that the ANN, or future iterations thereof, can provide an evidence-based tool to assist in prognostication and patient-counseling immediately after CSF shunt placement.

Lung destruction secondary to intrapulmonary migration of a ventriculoperitoneal shunt catheter: report of an unusual case and literature review.

Ventriculoperitoneal shunt placement for the treatment of hydrocephalus is one of the most common pediatric neurosurgical procedures. Complications, including infections, catheter obstruction, shunt breakdown, and hemorrhage, have been described in the literature. Occasionally, however, uncommon and devastating complications occur. We report a case of a 10-year-old female patient who at birth underwent surgical closure of lumbar myelomeningocele and placement of a CSF shunt at another center. Her neurosurgical follow-up was poor. She presented at our institution with a history of recurrent pneumonia. Control chest X-rays showed a right pulmonary infiltrate with lung retraction and mediastinal shift. Chest and brain CT scans confirmed the intrapulmonary location of the distal catheter tip and ventricular dilation. Surgical shunt revision was performed with removal of the intrapulmonary catheter and placement of a new intraperitoneal catheter. Subsequently, right pneumonectomy was performed with good postoperative recovery of the patient. Intrathoracic migration of the distal catheter of the CSF shunt is an extremely rare complication that may produce severe morbidity. To our knowledge, there have been no previous reports on extensive lung destruction secondary to intrathoracic and intrapulmonary ventriculoperitoneal shunt migration. In patients with CSF shunts and pulmonary symptoms, intrapulmonary catheter migration should be considered.

Complications of CSF Shunts in Pediatrics: Functional Assessment With CSF Shunt Scintigraphy-Performance and Interpretation.

OBJECTIVE. The purpose of this article is to review the performance method and criteria for interpretation of CSF shunt scintigraphy studies. CONCLUSION. Interpretation of CSF shunt scintigraphy studies requires an in-depth understanding of hydrocephalus, the functioning of CSF shunts and their components, and the mechanisms of failure of such devices. Application of strict interpretive criteria when evaluating CSF shunt scintigraphy studies improves diagnostic yield, providing valuable functional information to the neurosurgical team who manages patients with shunted hydrocephalus.

Visual failure and sinus thrombosis following depressed skull fracture: management with single session lumboperitoneal shunt and sinus decompression -case report.

Elevation of a depressed skull fracture (DSF) overlying a venous sinus is generally avoided due to risk of sinus injury. Rarely, the sinus may be compressed by the fractured segment, causing intracranial hypertension (IH) or encephalopathy and can only be diagnosed with cerebral angiography or MR imaging techniques. The posterior third of the superior sagittal sinus (SSS) was found involved in all the reported cases. There is no consensus on its management, but most patients did not have any sinus thrombosis and improved after elevation of the compressing DSF alone. There are isolated reports of improvement with serial lumbar punctures or ventriculoperitoneal shunt.We report for the first time, a single session lumboperitoneal shunt and DSF elevation for a patient with thrombosis of the posterior part of SSS due to an overlying DSF, causing florid papilledema and impending blindness. Elevation of the DSF alone would not have achieved patency of the thrombosed sinus immediately to save his vision. Hence a lumboperitoneal shunt was done for immediate relief of IH. This CSF diversion alone was insufficient to achieve patency of the thrombosed sinus in the presence of significant external compression by the DSF; even if anticoagulants were used. Hence we elevated the DSF after craniotomy using a technical modification; by making a wide gutter circumferentially around the DSF with a high speed drill, to avoid sinus injury; prior to its elevation. The patient's vision improved in 48 hours and anticoagulants were used till 2 months when sinuses were found normal on MRI. Serial CT &MR images showing progression to thrombosis and recovery after decompression are presented. Both CSF diversion and DSF elevation are necessary when vision is threatened by IH due to sinus thrombosis with an overlying DSF.

Integrated fundal assessment pathway for patients with suspected shunt malfunction via digital retinal images.

Introduction: Papilloedema is an important clinical sign in the assessment of neurosurgical patients presenting with suspected shunt malfunction.Methods: We describe our 18-month experience using a newly acquired nonmydriatic digital retinal camera to acquire fundal photographs for this purpose.Results: It was used to take digital photographs in 67 patients presenting with suspected shunt malfunction and 54% of these images were discussed with the on-call ophthalmology team for advice. Of these 81% had instant input provided by ophthalmology and the remainder were sent to the ophthalmology department for formal assessment. Of all shunt related regional referrals in the same time period, we found that only 13% of the referred patients were discussed with the on-call ophthalmology team. The rest had decisions made by the on-call neurosurgical team.Conclusions: We believe this new integrated pathway is clinically and cost-effective and recommend it as a useful tool in other neurosurgical units.

Cerebrospinal fluid diversion versus bariatric surgery in the management of idiopathic intracranial hypertension.

Background: Idiopathic intracranial hypertension (IIH) is a condition affecting predominantly young women with increased body mass index (BMI). Obesity with the related metabolic and biochemical complications are thought to be involved in the pathogenesis of the condition. The aim of this study is to evaluate the safety, outcomes and economic implications of two treatment options for IIH.Methods: We retrospectively analysed cases of morbidly obese IIH patients treated by cerebrospinal fluid (CSF) shunting procedures between 2006 and 2016 in our department and compared their outcome with that of 69 patients undergoing bariatric surgery between 2015 and 2016.Results: A total of 42 female patients with IIH underwent de-novo shunting procedures during the study period. There was a high rate of shunt revisions (67%) and further weight gain in the majority of patients who had the insertion of CSF shunts. Of the 69 female patients undergoing bariatric surgery 4.3% required interventions related to their surgery with a significantly fewer number of hospital inpatient days. Furthermore, in the patients undergoing bariatric surgery, there was a significant improvement in all obesity-related complications.Conclusions: CSF shunting procedures do not address the aetiological factor of IIH and are associated with high rates of morbidity and further weight gain. Bariatric surgery is not only efficacious in the management of patients with IIH but is associated with significant improvements in other obesity-related comorbidities. Bariatric surgery is safe and more cost-effective than CSF shunting.

Idiopathic intracranial hypertension VISION (venous intervention versus shunting in IIH for optic nerve disc swelling) trial: patient perspective questionnaire.

INTRODUCTION: Headaches, visual problems and tinnitus are symptoms of Idiopathic Intracranial Hypertension (IIH) which resolve with reduction of CSF pressure. Impaired cranial venous outflow has been implicated in the pathogenesis and there is evidence of good treatment results in IIH using venous sinus stenting. We are currently initiating a multi-centre randomised controlled trial, the VISION study (Venous Intervention versus Shunting in IIH for Optic Disc Swelling) comparing radiological (venous sinus stenting) to surgical intervention (CSF shunting). As part of the preparations for VISION we made a basic questionnaire available to members of the website IIH UK ( www.iih.org.uk ). METHODS: 10-point questionnaire pertaining to IIH diagnosis, symptoms and management using www.surveymonkey.com . RESULTS: 250 questionnaires were returned. 95.6% of respondents were female, mostly ≤40 years of age. 70% were diagnosed in the last 5 years, but only 35% were diagnosed less than a year after onset of symptoms. 59.4% of patients had not undergone any radiological/surgical intervention, 34.9% had had CSF diversion, 3.6% venous stenting and 2.0% had stent plus shunt. 16.8% indicated their lives were most affected by tinnitus and 18.1% by visual problems, but 49.6% said they were most affected by their headaches. 81% of patients indicated they would be happy to participate in a randomised trial comparing the two treatment options of venous stenting and CSF shunting. CONCLUSION: IIH patients want to be actively involved in their treatment and are favourably disposed towards clinical research. Variation exists in treatment modalities offered. There are individual differences regarding impact of symptoms.

Impact of Serum Vancomycin Trough Levels in the Treatment of Central Nervous System Shunt Infections Caused by Coagulase-Negative Staphylococci.

Coagulase-negative staphylococci (CoNS) are a common cause of pediatric ventricular shunt infections. The Infectious Diseases Society of America recommends vancomycin serum troughs of 15-20 µg/mL when treating CoNS shunt infections in adult patients. We report a series of pediatric cases of CoNS shunt infections in which clinical cure was obtained with troughs < 15 µg/mL. These findings question the relevance of this recommendation in pediatric patients.

Transitioning in hydrocephalus: Current practices in Canadian Paediatric Neurosurgery centres.

INTRODUCTION: Advances in perinatal care in the developed world have resulted in more children living into adulthood with complex chronic health conditions. Transition is a process to improve and maximize the functional status of adolescents via the provision of adequate and appropriate health services in adulthood. This process is frequently disjointed, fragmented and inconsistent and inadequate transition increases morbidity, hospital admissions and urgent interventions. Ten thousand children are diagnosed with hydrocephalus annually in North America. Most survive to adulthood yet there are few transitioning programs and little research data on successful programs for this population. METHODS: An email survey of paediatric neurosurgical centres in Canada was carried out to establish current transition practices and attitudes for adolescents with hydrocephalus. Data were analyzed descriptively. RESULTS: Eleven out of 12 centres responded. The age of transition ranged from 16 to 18 years. Four centres have access to a dedicated Adult Hydrocephalus Clinic. Referral practices vary between centres and we highlight inconsistencies in care to this cohort of patients in Canada. There is little satisfaction among neurosurgeons with current transition arrangements in Canada. Several suggestions were made on how to improve this process. CONCLUSION: We recommend research into the needs of patients with hydrocephalus in order to formalize appropriate standards for transitioning patients with a view to developing national guidelines to standardize the transition process. This will require input from patients, families and the wider medical and allied health professional groups.

Management of Ventriculoperitoneal Shunt Infections in Adults: Analysis of Risk Factors Associated With Treatment Failure.

Background: Little is known regarding the optimal treatment of ventriculoperitoneal (VP) shunt infections in adults. Our aim was to assess the efficacy of treatment strategies and to identify factors that predict failure. Methods: Retrospective, observational study of patients aged ≥12 years with VP shunt infections (1980 -2014). Therapeutic approaches were classified under 4 headings: only antibiotics (OA), one-stage shunt replacement (OSSR), two-stage shunt replacement (TSSR), and shunt removal without replacement (SR). The primary endpoint was failure of the treatment strategy, defined as the absence of definite cerebrospinal fluid (CSF) sterilization or related mortality. The parameters that predicted failure were analyzed using logistic regression. Results: Of 108 episodes (51% male, median age 50 years), 86 were analyzed. Intravenous antibiotics were administered for a median of 19 days. Eighty episodes were treated using strategies that combined antibiotic and surgical treatment (37 TSSR, 24 SR, 19 OSSR) and 6 with OA. Failure occurred in 30% of episodes, mostly due to lack of CSF sterilization in OSSR and OA groups. Twelve percent died of related causes and 10% presented superinfection of the CSF temporary drainage/externalized peritoneal catheter. TSSR was the most effective strategy when VP shunt replacement was attempted. The only independent risk factor that predicted failure was retention of the VP shunt, regardless of the strategy. Conclusions: This is the largest series of VP shunt infections in adults reported to date. VP shunt removal, particularly TSSR when the patient is shunt dependent, remains the optimal choice of treatment and does not increase morbidity.

I can hear my shunt-audible noises associated with CSF shunts in hydrocephalic patients.

BACKGROUND: Cerebrospinal fluid (CSF) shunts are life-long implants, and patients have reported anecdotally on noises associated with their shunts. There is, however, a marked lack of information regarding acoustic phenomena related to CSF shunts. METHODS: We identified all patients who had been treated or followed in our neurosurgical department within a 15-year period from January 2000 up to the end of 2014. After approval of the local ethics committee all patients who were cognitively intact were explored by a questionnaire and by personal interview about acoustic phenomena related to their shunts. RESULTS: Three hundred forty-seven patients were eligible for the survey, and 260 patients completed the questionnaire. Twenty-nine patients (11.2%) reported on noises raised by their shunts. All of them experienced short-lasting noises while changing body posture, mainly from a horizontal to an upright position, or while reclining the head. Most of the patients reported on soft sounds, but loud and even very loud noises occurred in some patients. Seventy-six percent of the patients were not bothered by these noises as they considered it as a normal part of the therapy or as proof that the shunt device was functioning. Modern valves with gravitational units are prone to produce noises in young adults, but nearly all valve types can evoke noises. CONCLUSIONS: Noises caused by a shunt do occur in a considerable number of patients with shunts. One should be aware of this phenomenon, and these patients must be taken seriously.