Jonathan Roth

Endoscopic Third Ventriculostomy in the Treatment of Childhood Hydrocephalus

OBJECTIVE To develop a model to predict the probability of endoscopic third ventriculostomy (ETV) success in the treatment for hydrocephalus on the basis of a childs individual characteristics. STUDY DESIGN We analyzed 618 ETVs performed consecutively on children at 12 international institutions to identify predictors of ETV success at 6 months. A multivariable logistic regression model was developed on 70% of the dataset (training set) and validated on 30% of the dataset (validation set). RESULTS In the training set, 305/455 ETVs (67.0%) were successful. The regression model (containing patient age, cause of hydrocephalus, and previous cerebrospinal fluid shunt) demonstrated good fit (Hosmer-Lemeshow, P = .78) and discrimination (C statistic = 0.70). In the validation set, 105/163 ETVs (64.4%) were successful and the model maintained good fit (Hosmer-Lemeshow, P = .45), discrimination (C statistic = 0.68), and calibration (calibration slope = 0.88). A simplified ETV Success Score was devised that closely approximates the predicted probability of ETV success. CONCLUSIONS Children most likely to succeed with ETV can now be accurately identified and spared the long-term complications of CSF shunting.

Subependymal Giant Cell Astrocytoma: Diagnosis, Screening, and Treatment. Recommendations From the International Tuberous Sclerosis Complex Consensus Conference 2012

BACKGROUND Tuberous sclerosis complex is an autosomal dominant disorder predisposing to the development of benign lesions in different body organs, mainly in the brain, kidney, liver, skin, heart, and lung. Subependymal giant cell astrocytomas are characteristic brain tumors that occur in 10% to 20% of tuberous sclerosis complex patients and are almost exclusively related to tuberous sclerosis complex. Subependymal giant cell astrocytomas usually grow slowly, but their progression ultimately leads to the occlusion of the foramen of Monro, with subsequent increased intracranial pressure and hydrocephalus, thus necessitating intervention. During recent years, secondary to improved understanding in the biological and genetic basis of tuberous sclerosis complex, mammalian target of rapamycin inhibitors have been shown to be effective in the treatment of subependymal giant cell astrocytomas, becoming an alternative therapeutic option to surgery. METHODS In June 2012, an International Tuberous Sclerosis Complex Consensus Conference was convened, during which an expert panel revised the diagnostic criteria and considered treatment options for subependymal giant cell astrocytomas. This article summarizes the subpanels recommendations regarding subependymal giant cell astrocytomas. CONCLUSIONS Mammalian target of rapamycin inhibitors have been shown to be an effective treatment of various aspects of tuberous sclerosis complex, including subependymal giant cell astrocytomas. Both mammalian target of rapamycin inhibitors and surgery have a role in the treatment of subependymal giant cell astrocytomas. Various subependymal giant cell astrocytoma-related conditions favor a certain treatment.

MRI Characterization and Longitudinal Study of Focal Cerebellar Lesions in a Young Tuberous Sclerosis Cohort

BACKGROUND AND PURPOSE: There are few articles characterizing cerebellar lesions in patients with TSC and no published series documenting longitudinal evaluation of these lesions, to our knowledge. Recent suggestion of a correlation between autism and cerebellar lesions in patients with TSC heightens the importance of understanding these lesions. Our purpose was to characterize cerebellar lesions in a cohort of young patients with TSC with specific interest in assessing longitudinal changes. MATERIALS AND METHODS: We retrospectively reviewed MR images from 145 pediatric and young adult patients with tuberous sclerosis (mean age, 7.6 years). A number of imaging characteristics of cerebellar tubers were recorded, and patients were evaluated for SGAs. Patients with follow-up scans >3 months from the original scan were further analyzed for longitudinal tuber characterization. RESULTS: There were 24.1% of patients with focal cerebellar lesions; 52.4% of patients with cerebellar lesions demonstrated change in imaging characteristics during longitudinal analysis. Fifty-one percent of the lesions were enhanced after gadolinium administration. Twenty percent of the patients with cerebellar lesions had pathologically confirmed SGAs compared with the incidence of 11% in the 145 patients with TSC reviewed. CONCLUSIONS: In our large cohort of young patients with TSC, cerebellar tubers were common and 52% of patients had tubers that changed with time. A higher percentage of patients with cerebellar lesions developed SGAs than patients with TSC without cerebellar lesions. Because this is the first reported longitudinal study of cerebellar lesions in TSC, further investigation may provide additional insight into TSC pathology and associated clinical manifestations, such as autism, developmental delay, and seizures.

Real-time neuronavigation with high-quality 3D ultrasound SonoWand in pediatric neurosurgery.

Intraoperative ultrasound (IOUS) serves as a basic imaging tool in neurosurgery. However, its low quality and difficulty in interpreting the images make its use as a resection control tool and navigation system cumbersome. We present our experience using a high-resolution 3D IOUS system combined with a navigation system in pediatric cranial surgery. We retrospectively reviewed 16 pediatric neurosurgical procedures in which a high-resolution 3D IOUS combined with a navigation system was used. The system enables basic navigation based on preoperative computed tomography or magnetic resonance imaging scans. In addition, IOUS images serve as a data set for updated intraoperative navigation. The indications for IOUS were preoperative navigation to define the skin incision and exact craniotomy site, and for real-time neuronavigation and resection control during tumor removal. The added time per case was short and no technical difficulties were encountered. High-resolution 3D IOUS combined with navigation systems has advantages for the pediatric neurosurgical population, including both real-time basic navigation and improved resection control.

Combined rigid and flexible endoscopy for tumors in the posterior third ventricle.

OBJECT Tumors leading to occlusion of the sylvian aqueduct include those of pineal, thalamic, and tectal origins. These tumors cause obstructive hydrocephalus and thus necessitate a CSF diversion procedure such as an endoscopic third ventriculostomy (ETV), often coupled with an endoscopic biopsy (EBX). Lesions located posterior to the massa intermedia pose a technical challenge, as the use of a rigid endoscope for performing both an ETV and EBX is limited. The authors describe their experience using a combined rigid and flexible endoscopic procedure through a single bur hole for both procedures in patients with posterior third ventricular tumors. METHODS Since January 2012, patients with posterior third ventricular tumors causing hydrocephalus underwent dual ETV and EBX procedures using the combined rigid-flexible endoscopic technique. Following institutional review board approval, data from clinical, radiological, surgical, and pathological records were retrospectively collected. RESULTS Six patients 3.5-53 years of age were included. Lesion locations included pineal (n = 3), fourth ventricle (n = 1), aqueduct (n = 1), and tectum (n = 1). The ETV and EBX were successful in all cases. Pathologies included pilocytic astrocytoma, pineoblastoma, ependymoma Grade II, germinoma, low-grade glioneural tumor, and atypical choroid plexus papilloma. One patient experienced an immediate postoperative intraventricular hemorrhage necessitating evacuation of the clots and resection of the tumor, eventually leading to the patients death. CONCLUSIONS The authors recommend using a combined rigid-flexible endoscope for endoscopic third ventriculostomy and biopsy to approach posterior third ventricular tumors (behind the massa intermedia). This technique overcomes the limitations of using a rigid endoscope by reaching 2 distant regions.

Quality of life following epilepsy surgery for children with tuberous sclerosis complex

Parents of children with tuberous sclerosis complex who underwent multistage resections for treatment of refractory seizures were offered a telephone questionnaire regarding quality of life (QOL) of child and family since surgery. Of 53 families, 39 responded. Age at epilepsy onset was birth to 3 months. Average duration of epilepsy before the first surgery was 5.1 years, and average age at surgery was 5.8. The average follow-up was 3.9. Seventy-seven percent had a >90% reduction in disabling seizures. In all outcome categories, 46-85% had at least a moderate improvement in QOL. There was a significant correlation between QOL variables and Engel outcome class. Despite the potential burden posed by the aggressive surgical approach, including multiple surgeries and long hospitalization periods, 94% of parents would choose the same course once again. We conclude that aggressive surgical treatment of tuberous sclerosis complex-related refractory seizures is associated with significant control of epilepsy as well as improved QOL for the patient and family.

Endoscopic third ventriculostomy in patients with a diminished prepontine interval

OBJECT Fenestration of the floor of the third ventricle is vital to the success of endoscopic third ventriculostomy (ETV) in treating patients with noncommunicating hydrocephalus. A generous prepontine interval (PPI) is generally accepted as one anatomical feature that may affect the safety and functionality of ETV. Whether a diminished PPI influences the safety or success of ETV, however, has not been adequately assessed. METHODS A review was conducted on the last 100 ETV procedures performed by the first author (M.M.S.). From archived preoperative MR imaging studies, the PPI was measured between the dorsum sellae and the basilar artery. For any patient with an interval of <or=1 mm, the technical and functional success of the procedure was recorded. Technical success was defined when a surgically created fenestration was accomplished without patient morbidity. Functional success was defined as the patient not needing any additional CSF diversionary procedure within 3 months after ETV. RESULTS In the entire cohort, the PPI ranged from 0 to 9.5 mm (mean 3.2 mm). There were 15 procedures performed in patients with a PPI of <or=1 mm. In all 15 procedures, a fenestration of the tuber cinereum was accomplished without vascular injury or patient morbidity. The ETV was successful in 11 patients (73.3%). All 4 failures occurred in children who had surgery during infancy (mean age 11 months). CONCLUSIONS Patients with an obliterated or reduced PPI can safely undergo ETV. The functional success rate appears equivalent to historical controls. Most failures in this series may be attributed to other patient characteristics, namely young age at the time of ETV.

Intraoperative Portable 0.12-Tesla MRI in Pediatric Neurosurgery

Objectives: Intraoperative MRI (iMRI) is used mainly in the adult neurosurgical population. The main indications for iMRI usage are resection control and updated intraoperative navigation capabilities. In this paper we present our experience using this technique in children. Specific advantages of iMRI for this age group are discussed. Methods and Results: We retrospectively reviewed 31 pediatric neurosurgical procedures in which a portable iMRI system was used. The indications for iMRI usage were preoperative navigation, resection control during tumor removal, shunt placements, and needle biopsy. In 7 children the use of the iMRI changed the course of the surgical procedure. Operative morbidity and mortality were not increased with use of the iMRI. Conclusions: iMRI systems have advantages for the pediatric neurosurgical population, including both real-time basic navigation and improved resection control.

Classical and real-time neuronavigation in pediatric neurosurgery

IntroductionNeuronavigation has become a cornerstone of neurosurgery. Navigation systems are categorized into two main groups: those based on preoperative imaging and those based on real-time intraoperative acquired images.ObjectivesThe preoperative imaging systems, either computed tomography (CT)- or magnetic resonance imaging (MRI)-based, are straight-forward systems that are routinely used in most institutions. Image accuracy, however, decreases secondary to brain and lesion shifts that occur during surgery. Intraoperative, real-time navigation systems overcome anatomical shifts by updating the image base of the navigation during surgery, thus, maintaining precise navigation capabilities throughout the surgical procedure.ConclusionsIn this article, we review the main neuronavigation systems and their applications, emphasizing their unique advantages and usage within the pediatric population.

Delayed contrast extravasation MRI: a new paradigm in neuro-oncology

BACKGROUND Conventional magnetic resonance imaging (MRI) is unable to differentiate tumor/nontumor enhancing tissues. We have applied delayed-contrast MRI for calculating high resolution treatment response assessment maps (TRAMs) clearly differentiating tumor/nontumor tissues in brain tumor patients. METHODS One hundred and fifty patients with primary/metastatic tumors were recruited and scanned by delayed-contrast MRI and perfusion MRI. Of those, 47 patients underwent resection during their participation in the study. Region of interest/threshold analysis was performed on the TRAMs and on relative cerebral blood volume maps, and correlation with histology was studied. Relative cerebral blood volume was also assessed by the study neuroradiologist. RESULTS Histological validation confirmed that regions of contrast agent clearance in the TRAMs >1 h post contrast injection represent active tumor, while regions of contrast accumulation represent nontumor tissues with 100% sensitivity and 92% positive predictive value to active tumor. Significant correlation was found between tumor burden in the TRAMs and histology in a subgroup of lesions resected en bloc (r(2) = 0.90, P < .0001). Relative cerebral blood volume yielded sensitivity/positive predictive values of 51%/96% and there was no correlation with tumor burden. The feasibility of applying the TRAMs for differentiating progression from treatment effects, depicting tumor within hemorrhages, and detecting residual tumor postsurgery is demonstrated. CONCLUSIONS The TRAMs present a novel model-independent approach providing efficient separation between tumor/nontumor tissues by adding a short MRI scan >1 h post contrast injection. The methodology uses robust acquisition sequences, providing high resolution and easy to interpret maps with minimal sensitivity to susceptibility artifacts. The presented results provide histological validation of the TRAMs and demonstrate their potential contribution to the management of brain tumor patients.