Faculty Bibliography

OBJECT: The goal of this study was to evaluate the safety, efficacy, and indications for repeat endoscopic third ventriculostomies (ETV). METHODS AND RESULTS: We reviewed the records of 20 patients who had undergone repeat ETV from 1987 to 1999. Their ages ranged from 8 months to 53 years (mean 17 years). The primary etiologies of hydrocephalus were: primary aqueductal stenosis (9 cases), tumor (5), Chiari malformation (2), prior infection (2), prior intraventricular hemorrhage (1), and blocked foramen of Monro (1 patient). The interval between the first and second ETVs ranged from 8 days to almost 6 years (mean 12.8 months). The intraoperative findings at repeat surgery were: occlusion of the primary orifice by scar (10 cases), virginal floor of the third ventricle (5 cases), pinhole ventriculostomy (3 cases), incompletely penetrated membrane (1 case), and blood clot occluding the orifice (1 case). The follow-up period ranged from 3 to 47 months (median 20 months). Repeat ETV was successful in 13 patients (65%). These patients did not require further shunting or other procedures during follow-up. Seven patients (35%) required placement of a shunt after repeat ETV. Several complications were observed in 1 patient (5%), including seizures, elevated ICP, bilateral pulmonary edema, and cardiac arrhythmia. This patient ultimately recovered fully; the ETV was successful, and the patient did not require a shunt. CONCLUSIONS: Based on the experience of this group of patients, repeat ETV is as effective and as safe as a primary ETV procedure, and should be attempted in selected patients

Cerebral perfusion brain scintigraphy obtained in six unselected patients (age newborn to 14 years) from among 50 children with vein of Galen malformations was used in conjunction with magnetic resonance imaging to determine the basis of the neurological and cognitive abnormalities in patients with vein of Galen malformations (VGMs). Five had a hemiparesis - persistent, transient, or alternating. Four were developmentally delayed. Two had so far been cognitively normal and acquired a neurological deficit, following an embolization procedure. The school age patient had a nonverbal learning disability. Three had epilepsy and/or an abnormal electroencephalogram. Magnetic resonance imaging documented only the VGM, hydrocephalus and atrophy; one child with perinatal asphyxia had periventricular leukomalacia. Perfusion brain scintigraphy was normal in two (a normal infant, and a toddler with a hemiparesis and aphasia). Abnormal findings included: left parietal hypoperfusion, fronto-temporal atrophy, patchy flow; left fronto-temporal hypoperfusion, left hemiatrophy, bilateral medial temporal hypoperfusion, right cerebellar hypoperfusion; right temporal hypoperfusion, patchy flow; right hemiatrophy, occipital hypoperfusion. Perfusion brain scintigraphy findings correlated better with focal neurological and cognitive defects than did magnetic resonance imaging

OBJECTIVE: Indwelling intrathecal drug delivery systems are becoming increasingly important as a method of neuromodulation within the nervous system. In particular, intrathecal baclofen therapy has shown efficacy and safety in the management of spasticity and dystonia in children. The most common complications leading to explantation of the pumps are skin breakdown and infection at the pump implantation site. The pediatric population poses particular challenges with regard to these complications because appropriate candidates for intrathecal baclofen therapy are often undernourished and thus have a dearth of soft tissue mass to cover a subcutaneously implanted baclofen pump. We report a technique of subfascial implantation that provides greater soft tissue coverage of the pump, thereby reducing the potential for skin breakdown and improving the cosmetic appearance of the implantation site. METHODS: Eighteen consecutively treated children (average age, 8 yr, 7 mo) with spasticity and/or dystonia underwent subfascial implantation of a baclofen pump. These children's mean weight of 42.9 lb is less than the expected weight for a group of children in this age group, ranging from 4 years, 8 months, to 15 years, 7 months. In all patients, the pump was inserted into a pocket surgically constructed between the rectus abdominus and the external oblique muscles and the respective anterior fascial layers. RESULTS: At an average follow-up of 13.7 months, no infection or skin breakdown had occurred at the pump surgical site in any of the 18 patients. CONCLUSION: At this early follow-up, the subfascial implantation technique was associated with a reduced rate of local wound and pump infections and provided optimal cosmetic results as compared with that observed in retrospective cases

Low-grade gliomas comprise a heterogeneous group of tumors accounting for 30% to 40% of all primary central nervous system (CNS) neoplasms in the pediatric population. Management of these patients has evolved significantly over the past 2 decades, the present emphasis being on surgery. Adjuvant therapies, such as radiation and/or chemotherapy are generally withheld until symptomatic or radiographic progression is evident. The goal of surgery is gross total resection, while preserving maximal neurologic function. The goal of radiation and chemotherapy is to provide symptom and tumor control with minimal acute and late toxicities. Chemotherapy has the additional goal of deferring radiation to allow maximal development and maturation of the child's CNS. The incorporation of these 3 modalities into the overall care of the pediatric low-grade glioma patient involves the multidisciplinary input of the neurosurgeon, radiation oncologist, and pediatric neuro-oncologist both at time of diagnosis and throughout the course of their disease

PURPOSE: Progress has been made in the treatment of medulloblastoma, the most common childhood malignant brain tumor: However, many long-term survivors will have posttherapy growth hormone insufficiency with resultant linear growth retardation. Growth hormone replacement therapy (GHRT) may significantly improve growth, but there is often reluctance to initiate GHRT because of concerns of an increased likelihood of tumor relapse. PATIENTS AND METHODS: This study retrospectively reviewed the use of GHRT for survivors of medulloblastoma in 11 neuro-oncology centers in North America who received initial treatment for disease between 1980 and 1993 to determine its impact on disease control. A Landmark analysis was used to evaluate the relative risk of relapse in surviving patients. RESULTS: Five hundred forty-five consecutive patients less than 15 years of age at diagnosis were identified. Six-year progression-free survival (mean +/- SD) was 40% +/- 5% in children less than 3 years of age at diagnosis compared with 59% +/- 3% for older patients. Older patients with total or near-total resections (P = .003) and localized disease at diagnosis (P < .0001) had the highest likelihood of survival. One hundred seventy patients (33% +/- 3% of the cohort) received GHRT. GHRT use varied widely among institutions, ranging from 5% to 73%. GHRT was begun a mean of 3.9 years after diagnosis, later in children younger than 3 years at diagnosis (5.4 years). By Landmark analyses, for those surviving 2, 3, and 5 years after diagnosis, there was no evidence that GHRT increased the rate of disease relapse. CONCLUSION: This large retrospective review demonstrates that GHRT is underutilized in survivors of medulloblastoma and is used relatively late in the course of the illness. GHRT is not associated with an increased likelihood of disease relapse

OBJECTIVE: This study was performed to evaluate the association between the type of neurosurgeon (general or pediatric) and either the extent of tumor removal or the frequency of complications in children undergoing malignant brain tumor resections. METHODS: Data were analyzed from three recent Children's Cancer Group studies: two on medulloblastomas/primitive neuroectodermal tumors and one on malignant gliomas. Neurosurgeons were classified as general neurosurgeons, as designated pediatric neurosurgeons in their institutions, or as members of the American Society of Pediatric Neurosurgeons (ASPN), which requires pediatric neurosurgical experience and practice standards. RESULTS: Data forms from 732 children were analyzed; 485 were from children with medulloblastomas/primitive neuroectodermal tumors, and 247 were from children with malignant gliomas. Operations were performed by 269 neurosurgeons, including 213 general neurosurgeons, 29 designated pediatric neurosurgeons, and 27 ASPN members. The mean number of operations per surgeon was 1.8, 4.9, and 7.6 for general neurosurgeons, designated pediatric neurosurgeons, and ASPN members, respectively. There was a significant relationship between the extent of tumor resection or the amount of residual tumor and the type of neurosurgeon. Designated pediatric neurosurgeons and ASPN members were more likely to remove more than 90% of the tumor and to leave less than 1.5 cc of residual tumor than were general neurosurgeons (P<0.05). In these studies, the probability of extensive tumor removal correlated with the number of operations the neurosurgeon performed (P<0.01). Neurological complications occurred in the following proportion of cases: general neurosurgeons, 23%; designated pediatric neurosurgeons, 32%; and ASPN members, 18%. CONCLUSION: Pediatric neurosurgeons are more likely than general neurosurgeons to extensively remove malignant pediatric brain tumors. In these tumors, extent of removal has been demonstrated to influence survival

The clinical impact of Alzheimer's disease pathology at biopsy was investigated in 56 cognitively impaired patients undergoing shunt surgery for idiopathic normal pressure hydrocephalus (NPH). Cognition was measured by means of the global deterioration scale (GDS), the mini mental status examination (MMSE) and a battery of six psychometric tests. Gait was assessed using objective measurements of velocity and the ambulatory index (AI). The prevalence of cases exhibiting neuritic plaques (positive biopsies) increased in parallel with dementia severity from 18% for patients with GDS 3 to 75% for patients with GDS scores > or =6. Patients with positive biopsies were more cognitively impaired (higher GDS and lower MMSE scores) as well as more gait impaired (higher AI scores and slower velocities) than patients with negative biopsies. After surgery, gait velocity and AI scores improved significantly and to a comparable degree for patients with and without positive biopsies. Similar proportions of positive and negative biopsy patients also had improved gait as assessed by means of subjective video tape comparisons. There were no significant differences between the biopsy groups in the magnitude of postoperative psychometric change or in the proportion of cases exhibiting improved urinary control. Alzheimer's disease pathology is a common source of comorbidity in older patients with idiopathic NPH where it contributes to the clinical impairment associated with this disorder. For patients accurately diagnosed with NPH, concomitant Alzheimer's disease pathology does not strongly influence the clinical response to shunt surgery