Faculty Bibliography

OBJECT: In this study the authors evaluate the safety, efficacy, and indications for endoscopic third ventriculostomy (ETV) in patients with a history of subarachnoid hemorrhage or intraventricular hemorrhage (IVH) and/or cerebrospinal fluid (CSF) infection. METHODS: The charts of 101 patients from seven international medical centers were retrospectively reviewed; 46 patients had a history of hemorrhage, 42 had a history of CSF infection, and 13 had a history of both disorders. All patients experienced third ventricular hydrocephalus before endoscopy. The success rate for treatment in these three groups was 60.9, 64.3, and 23.1%, respectively. The follow-up period in successfully treated patients ranged from 0.6 to 10 years. Relatively minor complications were observed in 15 patients (14.9%), and there were no deaths. A higher rate of treatment failure was associated with three factors: classification in the combined infection/hemorrhage group, premature birth in the posthemorrhage group, and younger age in the postinfection group. A higher success rate was associated with a history of ventriculoperitoneal (VP) shunt placement before ETV in the posthemorrhage group, even among those who had been born prematurely, who were otherwise more prone to treatment failure. The 13 premature infants who had suffered an IVH and who had undergone VP shunt placement before ETV had a 100% success rate. The procedure was also successful in nine of 10 patients with primary aqueductal stenosis. CONCLUSIONS: Patients with obstructive hydrocephalus and a history of either hemorrhage or infection may be good candidates for ETV, with safety and success rates comparable with those in more general series of patients. Patients who have sustained both hemorrhage and infection are poor candidates for ETV, except in selected cases and as a treatment of last resort. In patients who have previously undergone shunt placement posthemorrhage, ETV is highly successful. It is also highly successful in patients with primary aqueductal stenosis, even in those with a history of hemorrhage or CSF infection

OBJECTIVE: To determine the value of delayed surgical resection in patients with central nervous system germ cell tumors who exhibit less than complete radiographic response despite declining serum and cerebrospinal fluid (CSF) tumor markers after initial chemotherapy. METHODS: We retrospectively analyzed 126 patients enrolled on two international multicenter clinical trials (the First and Second International Central Nervous System Germ Cell Tumor Studies) for patients with newly diagnosed central nervous system germ cell tumors. After at least three cycles of chemotherapy, 10 of these patients underwent delayed surgical resection owing to evidence of residual radiographic abnormalities despite declining or completely normalized serum and CSF levels of alpha-fetoprotein and human chorionic gonadotropin. RESULTS: Eight of these patients demonstrated nongerminomatous germ cell tumor elements at the time of initial diagnosis. In these patients, either serum or CSF tumor markers were elevated initially. Two patients demonstrated pure germinomas with normal levels of serum and CSF tumor markers. After chemotherapy, radiographic evaluation revealed a partial response in seven patients, a minor response in one patient, and stable disease in two patients. All 10 patients had either normal or decreasing levels of serum and CSF tumor markers before second-look surgery. At delayed surgical resection, 7 of the 10 patients underwent gross total resection, and 3 patients underwent subtotal resection of residual lesions. Pathological findings at second-look surgery demonstrated three patients to have mature teratomas, two with immature teratomas, and five with necrotic or scar tissue alone. To date, 7 of the 10 patients have had no recurrence during an average follow-up time of 36.9 months (range, 3-96 mo). Three of four patients with nongerminomatous germ cell tumors who had tumor markers that were decreased, but not normalized, before second-look surgery eventually developed tumor dissemination/progression, and they required subsequent radiation therapy despite having teratoma or necrosis/scar tissue at delayed surgery. In contrast, three of four patients with nongerminomatous germ cell tumors and completely normalized markers did not progress and did not require radiation therapy. CONCLUSION: Delayed surgical resection should be considered in patients with central nervous system germ cell tumors who have residual radiographic abnormalities and normalized tumor markers, because these lesions are likely to be teratoma or necrosis/scar tissue. However, second-look surgery should be avoided in patients whose tumor markers have not normalized completely

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