Open surgery for in utero repair of spina bifida: Microneurosurgery versus standard technique - A systematic review.

BACKGROUND/OBJECTIVES: Prenatal myelomeningocele (MMC) repair has been shown to improve neurological outcomes. It has been suggested that decreases in the hysterotomy diameter during surgery can improve perinatal outcomes without altering neurologic outcomes. The objective of this study is to describe and compare the main maternal and fetal outcomes of fetuses undergoing open surgery for MMC repair, through the different modifications (standard-classical, mini-hysterotomy, and microneurosurgery). DATA SOURCE: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Ovid, SciELO, LILACS, PROSPERO. RESULTS: From a total of 112 studies, seven case series were selected including 399 fetuses with open fetal surgery, five studies using the classical technique (n = 181), one with mini-hysterotomy (n = 176), and one with the microneurosurgery technique (n = 42). The mini-hysterotomy and microneurosurgery techniques presented a lower risk of preterm delivery (21.4% and 30%, respectively) compared to the classic technique (47.3%), premature rupture of membranes (78%, 62%, and 72.5 %, respectively), oligohydramnios (0% and 72.5%, respectively), dehiscence of hysterotomy, maintaining the same frequency of Chiari reversion (78%, 62%, and 72.5%, respectively), postnatal correction requirement (0%, 4.8%, and 5.8%, respectively), and lower frequency of requirement for a ventriculoperitoneal shunt placement (13.0%, 7.5%, and 29.1%, respectively). CONCLUSION: The least invasive techniques (minihysterotomy-microneurosurgery) are possible and reproduceable, as they are associated with better maternal and perinatal outcomes.

Characteristics and management of hydrocephalus associated with vestibular schwannomas: a systematic review.

Hydrocephalus (HC) can be associated with vestibular schwannoma (VS) at presentation. Although spontaneous resolution of HC after VS removal is reported, first-line treatment is varied including preoperative ventriculoperitoneal (VP) shunt, external ventricular drainage (EVD), or lumbar drainage (LD). We performed a systematic review to clarify optimal management of HC associated with VS at presentation, as well as characteristics of patients with initial and persistent HC after VS removal, and prevalence of HC associated with VS. Fourteen studies were included. Patients were grouped according to the timing of HC treatment. The overall rate of VP shunts was 19.4%. Among patients who received VS removal as first-line treatment, 6.9% underwent permanent shunts. In a subgroup of 132 patients (studies with no-aggregate data), t test analysis for mean tumor size (P = 0.02) and mean CSF protein level (P < 0.001) demonstrated statistically significant differences between patients with resolved HC (3.48 cm and 201 mg/dL) and patients with persistent HC (2.46 cm and 76.8 mg/dL) after VS resection. Transient treatment of HC using EVD or LD further resolved the HC in 87.5% and 82.9% of patients, respectively, before and after VS removal. The overall prevalence of HC associated with VS in a population of 2336 patients was 9.3%. Schwannoma removal as first-line treatment is justified by its low rate of persistent HC requiring VP shunt (roughly 7%). Patients with smaller VS and lower CSF proteins present higher risk of persistent HC after schwannoma removal. Temporary treatment of HC contributes to its resolution, both before and after VS removal.

Analysis of the Rate and Pattern of Ventriculoperitoneal Shunt Infection and Ventricular Catheter Culture Yield: A 10-Year Single-Institute Experience.

AIM: We aimed to study the rate and pattern of ventriculoperitoneal shunt (VPS) infections at the Jordan University Hospital (JUH) over 10 years and investigate the yield of ventricular catheter tip culture in the evaluation of shunt infection. PATIENTS AND METHODS: All patients operated on at our institution for ventriculoperitoneal shunt (VPS) insertion, reinsertion, and revision between 2009 and 2018 were included. Data (age, gender, pathology, and history of shunt infection) were collected from patients' files. Rates of infection and results of culture (cerebrospinal fluid and ventricular catheter tip) were obtained from laboratory records. RESULTS: According to our hospital database, 310 patients were eligible for this study. The rate of infection was 11.1% per ventriculoperitoneal procedure, and the most common -organism was coagulase-negative Staphylococcus (CoNS) which was the cause of infection in 51.4% of the cases. Twenty-one percent of proved shunt infection cases showed a positive ventricular catheter tip culture. CONCLUSION: The rate and pattern of shunt infections at our institution are comparable with the international figures and data. Methods of catheter tip culturing should be improved to increase the yield of this practice.

Usefulness of Brain Positron Emission Tomography with Different Tracers in the Evaluation of Patients with Idiopathic Normal Pressure Hydrocephalous.

Idiopathic normal pressure hydrocephalus (iNPH) is the only form of dementia that can be cured by surgery. Its diagnosis relies on clinical and radiological criteria. Identifying patients who can benefit from surgery is challenging, as other neurological diseases can be concomitant or mimic iNPH. We performed a systematic review on the role of positron emission tomography (PET) in iNPH. We retrieved 35 papers evaluating four main functional aspects with different PET radiotracers: (1) PET with amyloid tracers, revealing Alzheimer's disease (AD) pathology in 20-57% of suspected iNPH patients, could be useful in predictions of surgical outcome. (2) PET with radiolabeled water as perfusion tracer showed a global decreased cerebral blood flow (CBF) and regional reduction of CBF in basal ganglia in iNPH; preoperative perfusion parameters could predict surgical outcome. (3) PET with 2-Deoxy-2-[18F]fluoroglucose ([18F]FDG ) showed a global reduction of glucose metabolism without a specific cortical pattern and a hypometabolism in basal ganglia; [18F]FDG PET may identify a coexisting neurodegenerative disease, helping in patient selection for surgery; postsurgery increase in glucose metabolism was associated with clinical improvement. (4) Dopaminergic PET imaging showed a postsynaptic D2 receptor reduction and striatal upregulation of D2 receptor after treatment, associated with clinical improvement. Overall, PET imaging could be a useful tool in iNPH diagnoses and treatment response.

Diffuse intrinsic pontine glioma ventricular peritoneal shunt metastasis: a case report and literature review.

Dissemination of diffuse intrinsic pontine glioma (DIPG) outside the central nervous system is exceptional. Here, we present a child diagnosed with DIPG who developed seeding along the track of the ventriculoperitoneal shunt and review the literature on this unusual occurrence.

Predictive factors associated with ventriculoperitoneal shunting after posterior fossa tumor surgery in children.

PURPOSE: The aim of the study was to evaluate established risk factors and define new inflammation-associated factors associated with postoperative ventriculoperitoneal shunt placement. METHODS: The electronic medical records of children who underwent surgery for a tumor in the posterior fossa between January 2009 and January 2018 were retrospectively analyzed. Factors evaluated include age, clinical symptoms, tumor type, extent of surgical tumor resection, treatment with EVD and/or ETV, radiological findings, postoperative serum CRP, and leucocyte levels. Tumor tissue was stained immunohistochemically with antibodies against CD3, and leucocyte counts were performed. Patients with pre- or postoperative signs of infection or confirmation of a concurrent infection were excluded from some analyses. RESULTS: Seventy patients ages 0.4-20.8 years (median, 8.2) were included. Forty-five of 70 (65.3%) presented postoperative radiological signs of hydrocephalus. Fifteen of 70 (21.4%) patients required shunt placement postoperatively. Shunt placement was significantly associated with age < 3 years at diagnosis (p = 0.013), perioperative EVD placement (p < 0.001), signs of hydrocephalus in postoperative imaging (p = 0.047), a frontooccipital horn ratio (FOHR) > 0.46 within the first 72 h postoperatively (p < 0.001), and the presence of intraventricular blood postoperatively (p = 0.007). Six patients who underwent shunting had serum CRP levels > 40 mg/l (p = 0.030) within the first 48 h postoperatively. Tumor type or extent of resection did not correlate with shunt placement. CONCLUSIONS: Several established and new factors associated with shunt placement after posterior fossa tumor surgery could be identified. Additional studies are needed to explore the aseptic inflammation pathways involved with increased CRP levels and shunt placement.

Transventricular Migration of Choroid Plexus Carcinoma Causing an Intraoperative Conundrum: A Case Report with a Review of the Literature.

Migrating intracranial tumors are extremely rare occurrences in the neurosurgery literature. Introduction of any factor causing disequilibrium in cerebrospinal fluid circulation and pressure can potentially precipitate transventricular migration of pedunculated intraventricular lesions. The identification of such factors, prior to excision of intraventricular pedunculated tumors, is imperative to avoid intraoperative mismanagement. We report an extremely rare case of transventricular migration of a choroid plexus carcinoma in an infant, possibly precipitated by a ventriculoperitoneal (VP) shunt on the opposite side. This resulted in intraoperative confusion and a subsequent re-exploration of the opposite side for excision of the tumor. The literature provided only two similar occurrences in the past; however, in both cases, the migration was within the same ventricle and was documented prior to definitive resection. We report the first instance of transventricular migration of a tumor to the opposite ventricle following VP shunt which resulted in a negative intraoperative finding requiring a subsequent re-intervention on the opposite side. We believe that for any pedunculated intraventricular lesion, where an emergency management of hydrocephalus takes priority, a repeat neuroimaging is a must prior to definitive resection.

Association Between Possible Osteoporosis and Shunt-Dependent Hydrocephalus After Subarachnoid Hemorrhage.

Background and Purpose- Pathological obstruction in arachnoid granulations after subarachnoid hemorrhage (SAH) can impede cerebrospinal fluid flow outward to the venous sinus and causing hydrocephalus. Because bone and arachnoid granulations share the same collagen type, we evaluated the possible relation between bone mineral density and shunt-dependent hydrocephalus after SAH. Methods- We measured Hounsfield units of the frontal skull on admission brain computed tomography in patients with SAH. Receiver operating characteristic curve analysis was performed to determine the optimal cutoff Hounsfield unit in skull to predict osteopenia and osteoporosis in a large sample registry. According to the optimal cutoff skull Hounsfield unit values, study patients were then categorized as hypothetical normal, osteopenia, and osteoporosis. Odds ratios were estimated using logistic regression to determine whether the osteoporotic conditions are independent predictive factors for the development of shunt-dependent hydrocephalus after clipping for SAH. Results- A total of 447 patients (alive ≥14 days) with ruptured aneurysm SAH who underwent surgical clipping were retrospectively enrolled in this study during a 9-year period from 2 hospitals. We found that hypothetical osteoporosis was an independent predictor for shunt-dependent hydrocephalus after aneurysmal clipping for SAH after full adjustment for other predictive factors, including age (odds ratio, 2.08; 95% confidence interval, 1.06-4.08; P=0.032). Conclusions- Our study demonstrates a possible relation between possible osteoporosis and hydrocephalus after SAH. Hounsfield unit measurement on admission brain computed tomography may be helpful for predicting hydrocephalus during the clinical course of SAH in patients with osteoporosis or suspected osteoporosis.

Pediatric intracranial aneurysms: changes from previous studies.

PURPOSE: To develop a better understanding of pediatric intracranial aneurysms (PIAs). METHODS: All PIAs treated in our center from January 2012 to April 2017 were retrospectively included. Clinical data, treatment summaries, and follow-up outcomes were retrieved and analyzed. RESULTS: A total of 66 PIAs were found in 64 patients with a mean age of 11.4 ± 5.7 years, 68.8% of whom were male. The most common symptoms were seizure (n = 7, 63.6%) for the 0-5 age group and headache (n = 38, 71.7%) for the 6-18 age group. Fifty-one PIAs (77.3%) were located in the anterior circulation, with the middle cerebral artery (MCA) being the most common site (n = 28, 42.4%). Fifteen patients (23.4%) had PIAs that were pseudoaneurysms, and nine of them (60%) had a combined history of head trauma. Thirty-five patients (54.7%) had distal arterial aneurysms, and 21 of them (60%) presented with seizure. During a mean follow-up time of 1.6 ± 1.2 years, 79.7% of patients (n = 51) had favorable outcomes, 5 patients (7.8%) died, and the remaining 8 patients (12.5%) had unfavorable outcomes with severe neurological deficits. CONCLUSION: Apart from characteristics consistent with previous studies, several new findings regarding PIAs were reported, including a difference in the most common symptoms in different age groups, the MCA as the predominant location of PIAs, the high ratio of pseudoaneurysms and their head trauma etiology, and the incidence of distal arterial aneurysms and their relationship with the risk of seizures.

Implementing a digital real-time Hydrocephalus and Shunt Registry to evaluate contemporary pattern of care and surgical outcome in pediatric hydrocephalus.

OBJECTIVE: Treatment monitoring and outcome evaluation in pediatric hydrocephalus require gapless documentation regarding surgical and clinical follow-up data beginning from day 1 of treatment in order to apply high quality of care. Endoscopic procedures, shunt insertion and revision surgeries, and individual modifications of valve hardware or pressure settings during follow-up as well as established outcome measurements are highly relevant for complete illustration of the patient's hydrocephalus histories. A digital tool to capture, organize, and analyze comprehensive treatment-related data was estimated long overdue, consequentially developed, and implemented in daily pediatric neurosurgical routine. METHODS: We established a self-contained, network-capable database application to supply and back up clinical information of complete surgical treatment history with implant status and follow up for all institutional pediatric hydrocephalus patients from 1995 to date. The application content has been prospectively complemented since 2012 during daily pediatric neurosurgical routine. Beside surgical data, neurological outcome and quality of life assessment were integrated according to validated scales to be recordable 2, 3, and 5 years after initial surgical intervention for prospective administration. The application is in continuous and problem-free use since implementation offering homogeneous and structured real-time information of surgical and corresponding neurological hydrocephalus-related data. By using an automatized data extraction tool, an exemplary surgical outcome evaluation reviewing institutional ventriculo-peritoneal shunt (VPS) treatment in infants over a period of more than 20 years was performed. To validate applicability, the Registry was successfully implemented in an external institution under identical conditions continuously serving for the same purpose until today. RESULTS: Upon completion of the developing process, the application was successfully implemented into routine clinical workflow of our institution. In total, 579 pediatric hydrocephalus patients entered into the Registry with collectively 1874 corresponding hydrocephalus-related surgeries (9% neuro-endoscopic procedures, 18% temporary CSF-diversions, 73% shunt surgeries) so far. For exemplary surgical outcome analysis, the total volume of complex data sets could easily be reduced stepwise in regard to requested inclusion criteria. The selection process generated conclusive data of 256 institutional pediatric VPS patients providing a median follow-up of 8.5 years. Surgical outcome was evaluated in regard to hydrocephalus etiology, applied valve design, valve augmentation, cause of initial malfunction, time to initial shunt revision, and number of total revisions. CONCLUSION: The pediatric hydrocephalus registry application delivers easy access to contemporary and up-to-date clinical information during daily clinical routine and proves comprehensive value for various scientific purposes. Institutional hydrocephalus etiologies, treatment modalities, and surgical outcome could be reviewed for a selected pediatric patient collective during an interval of more than 20 years and confirmed initial shunt treatment within the first year of age, communicating hydrocephalus and a history of prematurity as significant variables for unfavorable shunt survival and long-term revision rate. At our institution, the Registry emerged to an essential and sustainable tool to capture, organize, and analyze patterns of care in pediatric hydrocephalus patients of all etiologies and treatment modalities. Because of its adaptable and reliable predicate, a prospective multi-center utilization is currently in preparation.

Chronic overdrainage syndrome: pathophysiological insights based on ICP analysis: a case-based review.

INTRODUCTION: Chronic overdrainage affects shunted patients producing a variety of symptoms that may be misdiagnosed. The best known symptoms are so-called shunt-related headaches. There is mounting evidence that changes in cerebrospinal venous system dynamics are a key factor to the pathophysiology of chronic overdrainage syndrome. CLINICAL PRESENTATION: We report the case of a 29-year-old woman with a shunt since the postnatal period suffering from chronic but the most severe intermittent headache attacks, despite an open shunt and with unchanged ventricular width during attacks. Intracranial pressure (ICP) recordings were performed during headache attacks and thereafter. DIAGNOSIS AND MANAGMENT: Massively increased ICPs, a continuous B wave "storm," and severely compromised intracranial compliance despite an open shunt were found, a scenario that was always self-limiting with the resolution of symptoms after several hours. When mobilized to the upright position, her ICPs dropped to - 17 mm Hg, proving shunt overdrainage. OUTCOME AND CONCLUSIONS: Symptomatology can only be explained by sudden venous entrapment following chronic venous distention as a result of chronic overdrainage. Subsequent therapeutic management with an overdrainage preventing shunt and satisfying clinical outcome with complete ceasing of headache attacks adds insight into the pathophysiology of chronic overdrainage syndrome.

Endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) in non-communicating hydrocephalus (NCH): comparison of outcome profiles in Nigerian children.

BACKGROUND: Endoscopic third ventriculostomy (ETV) and ventriculo-peritoneal shunt (VPS) although recognized surgical options for non-communicating hydrocephalus have debatable applications. OBJECTIVE: We analysed a prospective cohort of age-matched children with non-tumor, non-communicating hydrocephalus treated with the two surgical modalities using clinically measurable parameters. METHODS: A single institution analysis of age-matched patients with non-communicating hydrocephalus treated with VPS or ETV over a 3-year period. Occipitofrontal circumference (OFC), milestone, shunt independence as well as complication profiles of patients were recorded and analysed. Mean follow-up period was 1.27 ± 0.19 years 95%CI). Data analysis were performed using SPSS version 15, Chicago, IL. Statistical tests were set at 95% significance level. RESULTS: Fifty-five patients were enrolled, 25 patients had ETV, while 30 had VPS. Mean age was 2.3 ± 0.7 years (95% CI) with a range of 3 months to 4.5 years. Aqueductal stenosis was the most common indication. OFC profile decline was significant among the VPS group when compared with ETV group at 3 months follow-up (χ2 = 7.59, df = 1, p < 0.05). There was no difference among the two treatment groups χ2 = 2.47, df = 1, p > 0.05) in milestone profile. Thirteen percent of VPS, compared to (4%) ETV patients, had sepsis (χ2 = 4.59, df = 1 p < 0.05). Ninety-two percent of ETV patients remained shunt free, while 80% of shunted patients achieved ETV independence. Two patients died among the VPS group compared to one patient in the ETV group. CONCLUSION: VPS compared to ETV is associated with an earlier milestone and OFC response. ETV is associated with lower rates of sepsis and mortality.

Pregnancy and delivery after myelomeningocele repair, ventriculoperitoneal shunt implantation, and augmentation cystoplasty.

INTRODUCTION: Management of pregnancy and delivery of a patient with a history of myelomeningocele requires a multidisciplinary team approach. CASE REPORT: We report a case of pregnancy and delivery by a patient who had a history of myelomeningocele surgical repair, ventriculoperitoneal (VP) shunt, and bladder augmentation enterocystoplasty. Regarding types of delivery style, anesthesiologists recommended a Cesarean section under general anesthesia. However, urologists recommended a vaginal delivery because they were concerned that she would require a nephrostomy because of severe adhesion between her uterus and the neobladder if she had a Cesarean section. DISCUSSION: In a pregnant myelomeningocele patient with a VP shunt, neurosurgeons are expected to manage the VP shunt during pregnancy and delivery. The possible types of delivery style and the best options based on the neurological deficit should be discussed together with a medical team.

Treatment of abdominal pseudocysts and associated ventricuoperitoneal shunt failure.

PURPOSE: The purpose of this study was to determine whether drainage and revision are an effective treatment for abdominal pseudocyst associated ventriculoperitoneal (VP) shunt failure by estimating the total rate of secondary shunt failure. METHODS: We performed a retrospective review of children with hydrocephalus diagnosed with and treated for an abdominal pseudocyst at the Children's Hospital, London Health Sciences Centre (LHSC) between January 1, 2000 and May 31, 2016 (ethics approval # 108136). Patients with a VP shunt were included if (i) the development of an abdominal pseudocyst at age 2 to 18 years was identified, (ii) treatment of the pseudocyst by either interventional radiology (IR) or surgical drainage, and (iii) revision of the VP shunt. Demographic data and details of pseudocyst formation/ treatment as well as subsequent failures were identified. RESULTS: Twelve patients who had a VP shunt developed abdominal pseudocyst and met inclusion criteria. A 91% shunt failure rate after drainage and shunt revision was identified. Three patients had the pseudocyst drained in interventional radiology and then externalized due to shunt infection. Nine patients were treated by surgical revision. Ten patients experienced recurrent shunt failure following initial drainage of the pseudocyst: pseudocyst reoccurrence (n = 3), distal obstruction from adhesions (n = 1), and uncleared infection (n = 6). CONCLUSION: The results suggest that pseudocyst drainage and shunt revision is ineffective in providing long-term resolution of shunt problems.

Does Ventriculoperitoneal Shunting Improve Thyroid Hormone Levels in Hydrocephalic Newborns?

OBJECTIVE/AIM: The aim of this report was to investigate the effect of ventriculoperitoneal shunt insertion for the treatment of hydrocephalus on thyroid hormones in the first 3 months of life. METHODS: Thyroid-stimulating hormone (TSH), free T3 (fT3), and free T4 (fT4) levels were compared at 7 days (preoperatively) and at 30 and 90 days (postoperatively) after birth between 25 ventriculoperitoneal shunt-inserted hydrocephalic newborns and 20 healthy newborns. RESULTS: The TSH level at 7 days was higher in the hydrocephalic patient group (6.33 µIU) compared to the control group (3.76 µIU). This value was significantly decreased at 90 days in the ventriculoperitoneal shunt-inserted newborns (2.35 µIU) compared to the control group (3.33 µIU; p < 0.05). There were no significant differences between time points for fT4 and fT3 values in the patient group or for TSH, fT4, and fT3 values in the control group. CONCLUSION: We propose that a ventriculoperitoneal shunt inserted in the early period of life may have beneficial effects on thyroid hormones.

Predictors of Ventriculoperitoneal Shunt Failure in Children Undergoing Initial Placement or Revision.

BACKGROUND: Ventriculoperitoneal (VP) shunt placement, the mainstay of treatment for hydrocephalus, can place a substantial burden on patients and health care systems because of high complication and revision rates. We aimed to identify factors associated with 30-day VP shunt failure in children undergoing either initial placement or revision. METHODS: VP shunt placements performed on patients in the 2012-2013 American College of Surgeons National Surgical Quality Improvement Program (NSQIP) Pediatric were identified. RESULTS: VP shunts were placed in 3,984 patients either as an initial placement (n = 1,093) or as a revision (n = 2,891). Compared to the initial-placement group, the revision group was significantly more likely to experience shunt failure (14 vs. 8%, p < 0.0001). In the initial-placement group, congenital hydrocephalus was independently associated with shunt failure (OR 1.83; 95% CI 1.01-3.31, p = 0.047). In the revision group, cardiac risk factors (OR 1.38; 95% CI 1.00-1.90, p = 0.047), a chronic history of seizures (OR 1.33; 95% CI 1.04-1.71, p = 0.022), and a history of neuromuscular disease (OR 0.61; 95% CI 0.41-0.90, p = 0.014) were independently associated with shunt failure. CONCLUSIONS: Identifying the factors associated with VP shunt failure may allow the development of interventions to decrease failures. Further refinement of the collected variables in the NSQIP Pediatric specific to neurosurgical procedures is necessary to identify modifiable risk factors.

Late pediatric ventriculoperitoneal shunt failures: a Singapore tertiary institution's experience.

OBJECTIVE The introduction of ventriculoperitoneal shunts changed the way hydrocephalus was treated. Whereas much is known about the causes of shunt failure in the first few years, there is a paucity of data in the literature regarding the cause of late shunt failures. The authors conducted a study to find out the different causes of late shunt failures in their institution. METHODS A 10-year retrospective study of all the patients who were treated in the authors' hospital between 2006 and 2015 was conducted. Late shunt failures included those in patients who had to undergo shunt revision more than 5 years after their initial shunt insertion. The patient's notes and scans were reviewed to obtain the age and sex of the patient, the time it took for the shunt to fail, the reason for failure, and the patient's follow-up. RESULTS Forty-six patients in the authors' institution experienced 48 late shunt failures in the last 10 years. Their ages ranged from 7 to 26 years (12.23 ± 4.459 years [mean ± SD]). The time it took for the shunts to fail was between 6 and 24 years (mean 10.25 ± 3.77 years). Reasons for failure resulting in shunt revision include shunt fracture in 24 patients (50%), shunt blockage in 14 patients (29.2%), tract fibrosis in 6 patients (12.5%), shunt dislodgement in 2 patients (4.2%), and shunt erosion in 2 patients (4.2%). Postoperative follow-up for the patients ranged from 6 to 138 months (mean 45.15 ± 33.26 months). CONCLUSIONS Late shunt failure is caused by the effects of aging on the shunt, and the complications are different from early shunt failure. A large proportion are complications associated with shunt calcification. The authors advocate a long follow-up for pediatric patients with shunts in situ to monitor them for various causes of late shunt failure.

Role of radiological parameters in predicting overall shunt outcome after ventriculoperitoneal shunt insertion in pediatric patients with obstructive hydrocephalus.

OBJECTIVE Despite significant advances in the medical field and shunt technology, shunt malfunction remains a nightmare of pediatric neurosurgeons. In this setting, the ability to preoperatively predict the probability of shunt malfunction is quite compelling. The authors have compared the preoperative radiological findings in obstructive hydrocephalus and the subsequent clinical course of the patient to determine any association with overall shunt outcome. METHODS This retrospective study included all pediatric patients (age < 18 years) who had undergone ventriculoperitoneal shunt insertion for obstructive hydrocephalus. Linear measurements were taken from pre- and postoperative CT or MRI studies to calculate different indices and ratios including Evans' index, frontal horn index (FHI), occipital horn index (OHI), frontooccipital horn ratio (FOHR), and frontooccipital horn index ratio (FOIR). Other morphological features such as bi- or triventriculomegaly, right-left ventricular symmetry, and periventricular lucency (PVL) were also noted. The primary clinical outcomes that were reviewed included the need for shunt revision, time interval to first shunt revision, frequency of shunt revisions, and revision-free survival. RESULTS A total of 121 patients were eligible for the analysis. Nearly half of the patients (47.9%) required shunt revision. The presence of PVL was associated with lower revision rates than those in others (39.4% vs 58.2%, p = 0.03). None of the preoperative radiological indices or ratios showed any correlation with shunt revision. Nearly half of the patients with shunt revision required early revision (< 90 days of primary surgery). The reduction in the FOHR was high in patients who required early shunt revision (20.16% in patients with early shunt revision vs 6.4% in patients with late shunt revision, p = 0.009). Nearly half of the patients (48.3%) requiring shunt revision ultimately needed more than one revision procedure. Greater occipital horn dilation on preoperative images was associated with a lower frequency of shunt revision, as dictated by a high OHI and a low FOIR in patients with a single shunt revision as compared with those in patients who required multiple shunt revisions (p = 0.029 and 0.009, respectively). The mean follow-up was 49.9 months. Age was a significant factor affecting shunt revision-free survival. Patients younger than 6 months of age had significantly less revision-free survival than the patients older than 6 months (median survival of 10.1 vs 94.1 months, p = 0.004). CONCLUSIONS Preoperative radiological linear indices and ratios do not predict the likelihood of subsequent shunt malfunction. However, patients who required early shunt revision tended to have greater reductions in ventricular volumes on postoperative images. Therefore a greater reduction in ventricular volume is not actually desirable, and a ventricular volume high enough to reduce intracranial pressure is instead to be aimed at for long-term shunt compliance.

Imaging normal pressure hydrocephalus: theories, techniques, and challenges.

The pathophysiology of NPH continues to provoke debate. Although guidelines and best-practice recommendations are well established, there remains a lack of consensus about the role of individual imaging modalities in characterizing specific features of the condition and predicting the success of CSF shunting. Variability of clinical presentation and imperfect responsiveness to shunting are obstacles to the application of novel imaging techniques. Few studies have sought to interpret imaging findings in the context of theories of NPH pathogenesis. In this paper, the authors discuss the major streams of thought for the evolution of NPH and the relevance of key imaging studies contributing to the understanding of the pathophysiology of this complex condition.

Bulbar dysfunction in normal pressure hydrocephalus: a prospective study.

OBJECTIVE Normal pressure hydrocephalus (NPH) is clinically characterized by gait disturbance, cognitive impairment, and urinary incontinence, as well as enlargement of the ventricles. To the best of the authors' knowledge, there have been no previous publications regarding the correlation between bulbar dysfunction and NPH. The primary objective of this study was to compare preoperative and postoperative prevalence of bulbar dysfunction in patients with NPH. Secondary objectives included assessing the results of surgery for swallowing, speech, gait, cognition, and urination, and evaluating the correlation between bulbar dysfunction and triad symptoms. METHODS Fifty-three patients with NPH who underwent shunt placement surgery at Siriraj Hospital were included in the study. Patients were evaluated for gait, cognition, urination, swallowing, and speech before and 6 months after shunt placement. Triad symptoms were assessed using standard methods. Bulbar dysfunctions were assessed using the Swallowing Problem Questionnaire, Thai Articulation Test, Resonation Screening Test (RST), and Thai Nasality Test. The Thai Speech Assessment Program and nasometer were used for objective speech measurement. RESULTS Preoperatively, 86% (43/50) of patients had swallowing problems and 75% (37/49) had speech problems, as measured by the RST. Postoperatively, there was significant improvement in swallowing (p < 0.001), speech problems by RST (p = 0.008), and voice volume (p = 0.009), but no significant change in the nasometer test. All triad symptoms were improved. There were significant correlations between swallowing impairment and gait disturbance (r = 0.358, p = 0.009), and RST and cognitive impairment (r = -0.502, p < 0.001). CONCLUSIONS This is the first study of bulbar dysfunction in patients with NPH. The results showed that the prevalence of bulbar dysfunction is very high. The correlation between bulbar dysfunction and the classic NPH triad has been documented and published. These bulbar symptoms also significantly improved after surgery. As such, bulbar dysfunction should be regarded as a core symptom that should be considered along with the classic triad in the clinical diagnosis and management of NPH.