Temporizing treatment of hyperacute subdural hemorrhage by subdural evacuation port system placement.

An acute subdural hematoma (SDH) requiring surgical intervention is treated with craniotomy or craniectomy, in part because it is generally accepted that coagulated blood present in the acute phase cannot be adequately evacuated by less-invasive means such as bur hole drainage. However, a hyperacute SDH in the first few hours after trauma can have mixed-density components on CT scans that are thought to represent subdural blood that is not yet fully coagulated. The authors report a case in which a hyperacute SDH in a patient receiving antiplatelet therapy was treated with the novel technique of temporizing subdural evacuation port system (SEPS) placement. Placement of an SEPS in the intensive care unit allowed for rapid surgical treatment of the patient's elevated intracranial pressure (ICP) by drainage of 70 ml of fresh subdural blood. After initial SEPS-induced stabilization, the patient underwent operative treatment of the SDH by craniotomy. The combined approach of emergency SEPS placement followed by craniotomy resulted in a dramatic recovery, with improvement from coma and extensor posturing to a normal status on neurological evaluation 5 weeks later. In appropriately selected cases, patients with a hyperacute SDH may benefit from SEPS placement to quickly treat elevated ICP, as a bridge to definitive surgical treatment by craniotomy.

Myelomeningocele: characterization of a surgically induced sheep model and its central nervous system similarities and differences to the human disease.

OBJECTIVE: The purpose of this study was to determine how closely the surgically induced sheep myelomeningocele (MMC) model resembles the central nervous system derangements seen in human disease, and identify which aspects of MMC are the result of the early neuronal developmental defect, and which are secondary to the cerebrospinal fluid (CSF) drainage. STUDY DESIGN: An MMC-like lesion was created surgically in 16 fetal sheep at 75 days' gestation: 5 died in utero, 7 underwent no fetal repair, 4 were repaired (2-layer closure or biological glue) at 100 days' gestation. MMC sheep were delivered at term and allowed to survive up to 17 days for analysis of behavioral status and feeding behavior. Animals not repaired in utero were repaired at birth. All lambs were sacrificed and analyzed for hindbrain herniation, hydrocephalus, and other CNS derangements. RESULTS: Hindbrain herniation was observed in 43% of animals not repaired in utero, and in 1 lamb repaired with Bioglue. No animal developed hydrocephalus or other CNS derangements. CONCLUSION: Although this sheep MMC-like model reproduces the CSF leak, but not the developmental defect seen in humans, it suggests CSF leak contributes to hindbrain herniation seen in humans. This model may be useful to develop new minimally invasive techniques to halt CSF leak in utero.

Fetal magnetic resonance imaging enhances detection of spinal cord anomalies in patients with sonographically detected bony anomalies of the spine.

OBJECTIVE: Although fetal magnetic resonance imaging (MRI) is being increasingly used to evaluate sonographically suspected abnormalities, its utility in the evaluation of the spinal canal is not well studied. Because it is not susceptible to the limitations of fetal position, oligohydramnios, and shadowing from bony structures, we hypothesize that fetal MRI is better suited to assess the contents of the spinal canal compared with prenatal sonography. The purpose of this investigation was to determine whether fetal MRI could detect spinal abnormalities in cases in which they had not been originally suspected on prenatal sonography. METHODS: Fetal spine MR images were retrospectively reviewed over a 42-month period. Corresponding sonographic images were then rereviewed to determine whether there were findings in retrospect that might have suggested the cord abnormalities. Cases of myelomeningocele were counted as a spinal cord abnormality only if fetal MRI showed a cord anomaly other than the myelomeningocele. RESULTS: Of 33 cases referred for bony anomalies of the spine, fetal MRI showed additional abnormalities involving the spinal cord in 3 patients. These included diastematomyelia in 2 cases and segmental spinal dysgenesis in the third case. One case of diastematomyelia occurred in association with a lumbosacral myelomeningocele. The spinal cord anomalies were not visible on any of the prenatal sonograms, even in retrospect. CONCLUSIONS: Additional spinal cord anomalies were detected in 10% of cases reviewed. Fetal MRI can be useful in assessing the spinal cord in fetuses with bony spinal anomalies. Our findings suggest that fetuses with sonographically diagnosed bony abnormalities of the spine may benefit from further evaluation with fetal MRI.

Neurophysiological monitoring for safe surgical tethered cord syndrome release in adults.

BACKGROUND: Release of tethered spinal cord by sectioning of the filum terminale carries a significant risk of injury to the neighboring motor and sensory nerve roots. Intraoperative neurophysiological monitoring techniques can help to minimize these adverse neurologic outcomes. METHODS: We performed a retrospective review of 67 consecutive patients undergoing tethered cord release. We excluded 52 pediatric patients which limited our study to 15 adult patients treated during a four year period, including patients with a thick filum, low lying conus, myelomeningocele, filum tumor, spinal cord malformation, and/or lipoma. Clinical outcomes were determined from postoperative follow-up visits. Two patients were lost to follow up and were excluded from the clinical outcome analysis. Electrical stimulation of the filum terminale and lumbo-sacral nerve roots in conjunction with electromyogram (EMG) recording was performed intraoperatively. RESULTS: The mean electrical threshold for EMG response during stimulation of the filum terminale was 37.1 volts (V), range 15 to 100 V. In comparison, the lowest threshold obtained by direct stimulation of the ventral nerve roots was a mean of 1.46 V, with a range of 0.1 to 7 V. More than 70% of the patients studied demonstrated a filum to motor root threshold ratio of 100:1 or greater. No patient developed new neurologic symptoms or signs postoperatively. Bowel and bladder function improved in 46% of patients, back pain in 39% and motor function in 31%. Eight percent reported decline in bladder control and worsening back pain postoperatively. CONCLUSIONS: The often dramatic difference in the threshold of the filum terminale and adjacent motor nerve roots (100:1) helps to identify, isolate, and safely section the filum terminale. Tethered cord release using intraoperative neurophysiological monitoring is safe and in the majority of cases leads to improvement or at least, stabilization of neurologic function. Monitoring prevented intraoperative nerve root injury that might have resulted in immediate onset of new neurologic deficits caused by the surgical procedure.

Central neurocytoma: a review.

Central neurocytomas are rare intraventricular neoplasms of the central nervous system, compromising 0.25-0.5% of brain tumors. The diagnosis and management of these tumors remains controversial since most clinical series are small. Typically, patients with central neurocytomas have a favorable prognosis, but in some cases the clinical course is more aggressive. Although histological features of anaplasia do not predict biologic behavior, proliferation markers including MIB-1 might be more useful in predicting relapse. The most important therapeutic modality is surgery, and a safe maximal resection confers the best long-term outcome. In cases of a subtotal resection,'standard external beam radiation can be added or radiation can be delayed until tumor progression occurs. Smaller residual tumor volumes or recurrences can be treated with more conformal radiation or focused radiosurgery. Re-operation for recurrence should be considered if the procedure can be safely performed. Chemotherapy may be useful for recurrent central neurocytomas that cannot be resected and have been radiated, although long-term responses have not been reported for chemotherapy. Overall, this paper reviews the findings of the larger studies and highlights some of the important case reports that contribute to the current management of central neurocytomas.

The role of PCV chemotherapy in the treatment of central neurocytoma: illustration of a case and review of the literature.

BACKGROUND: Most central neurocytomas follow a benign clinical course. However, more aggressive variants have been described requiring additional surgical resection, radiation, or chemotherapy. Chemotherapy has rarely been used as an adjuvant therapy for central neurocytomas. METHODS: We report a case of a 20-year-old girl who underwent four subtotal resections, over the course of 3 years, for a large central neurocytoma that continued to progress. She was not a candidate for stereotactic radiosurgery, given the large tumor size. To avoid radiation injury in a young patient, she was treated with six cycles of chemotherapy including procarbazine, CCNU, and vincristine. Procarbazine was stopped after 2 cycles because of the development of a rash. Serial magnetic resonance imaging was used to follow treatment response. RESULTS: Her tumor started to decrease in size after 2 cycles of chemotherapy and continued to shrink until it stabilized after 5 cycles of chemotherapy. A small area of residual tumor with minimal enhancement persisted along the left lateral ventricle and remained stable for at least 16 months after the completion of chemotherapy. CONCLUSIONS: To our knowledge, this is only the fourth report describing the use of chemotherapy for progression of central neurocytomas as a treatment alternative to radiation therapy. The use of procarbazine, CCNU, and vincristine has not been previously described for the treatment of a central neurocytoma and presents an additional treatment option.

In utero surgery for hydrocephalus.

INTRODUCTION: Neonatal hydrocephalus is one of the most common congenital anomalies affecting the nervous system. DISCUSSION: Currently, ultrasonography allows for early detection of fetal ventriculomegaly and presents the family with several treatment options: termination of pregnancy, early delivery and neonatal shunting, and delivery at term followed by shunting. Despite ventricular decompression after birth, the cognitive outcome is variable as prolonged in utero hydrocephalus has a detrimental effect. In the early 1980s, fetal intervention was explored with the intention of improving outcome. However, patient selection was poor. Fetal ventriculomegaly from other conditions was not adequately distinguished from fetal hydrocephalus. In addition, fetal surgical techniques were not advanced. Consequently, the results were poor and a de facto moratorium on fetal shunting was imposed. However, recent improvements in fetal imaging, such as magnetic resonance imaging, and advances in fetal surgical techniques offer the possibility that properly selected fetuses with hydrocephalus can benefit from an in utero intervention.

In utero repair of myelomeningocele: experimental pathophysiology, initial clinical experience, and outcomes.

HYPOTHESIS: Experimental work raises the possibility that in utero repair of myelomeningocele (MMC) may improve lower extremity, bladder, and bowel function, ameliorate the Arnold-Chiari malformation, and decrease the need for postnatal shunting. DESIGN: We previously developed fetal lamb models to create and reverse lower extremity damage and the Arnold-Chiari malformation in utero. We then applied our extensive experience with fetal surgery, including fetal endoscopic (fetoscopic) surgical manipulation, to develop techniques for MMC repair. SETTING: A tertiary referral center. PATIENTS: All patients treated between 1998 and 2002 for a prenatally diagnosed MMC. INTERVENTIONS: Either fetoscopic MMC repair, fetoscopic patch repair, or limited maternal hysterotomy and microsurgical 3-layered fetal MMC repair was performed. MAIN OUTCOME MEASURES: Gestational age at delivery, survival, neurologic outcome, and need for ventricular shunting at 1 year. RESULTS: Complete fetoscopic repair was accomplished in 1 fetus. Two other fetuses underwent partial fetoscopic procedures. The remaining 10 patients underwent limited maternal hysterotomy and microsurgical 3-layered fetal MMC repair. Four of 13 patients died, and the mean gestational age at delivery of 11 fetuses born alive was 31 weeks. Five of 9 required ventricular shunting by age 1 year. In 2 patients, lower extremity function improved by more than 2 vertebral levels compared with prenatal ultrasonography. Five of 10 patients who lived longer than 3 weeks required postnatal wound revision within 7 days after birth. CONCLUSIONS: Fetoscopic repair, although feasible, does not yet yield optimal surgical results. Open surgical repair before 22 weeks' gestation is physiologically sound and technically feasible. One third of patients appear to be spared the need for a shunt at age 1 year, but improvement in distal neurologic function is less clear. Additionally, fetal mortality is associated with this procedure. Our results complement the data published by groups at Children's Hospital of Philadelphia, in Pennsylvania, and Vanderbilt University, Nashville, Tenn. A National Institutes of Health-sponsored prospective randomized trial is now underway at these 3 centers to compare fetal repair with postnatal repair.

Familial medulloblastoma: case report of one family and review of the literature.

OBJECTIVE AND IMPORTANCE: Medulloblastoma is the most common malignant brain tumor and the most common malignant solid tumor in children. Most medulloblastomas are sporadic, but rare familial forms have been described. To the best of our knowledge, only 10 case reports of familial medulloblastoma have been published. A variety of candidate genes have been suggested to be involved in familial medulloblastomas. However, the exact pathogenesis and genetics involved in familial medulloblastoma remain unknown. CLINICAL PRESENTATION: We describe the presentation of medulloblastoma in two siblings (one of each sex) and their great-uncle. The three cases differ with regard to age at onset and pathological subtype of medulloblastoma. INTERVENTION OR TECHNIQUE: Immunostaining of tissue blocks for gene products involved in medulloblastoma differed in the two siblings for beta-catenin and was similar with staining for gli. CONCLUSION: This article is only the second report in the literature to address the genetics of familial medulloblastoma in the absence of characterized conditions such as Li-Fraumeni's cancer syndrome and basal cell nevus, Rubinstein-Taybi's, and Turcot's syndromes. The discrepancy in beta-catenin staining in the two siblings suggests that the two tumors differentiated through divergent pathways. We briefly summarize all published cases of familial medulloblastoma and review the literature on the genes involved in medulloblastoma formation.

Clinical outcome in children undergoing tethered cord release utilizing intraoperative neurophysiological monitoring.

Release of tethered spinal cord by sectioning of the filum terminale carries a risk of injuring neighboring motor and sensory nerve roots involved in bowel and bladder control. Therefore, intraoperative neurophysiological monitoring techniques have been developed to prevent neurological complications postoperatively. We performed a retrospective chart review of 63 patients who had undergone tethered cord release. We excluded adult patients, those lost to follow-up and patients with either a myelomeningocele and/or lipoma. This limited our study to 25 pediatric patients, aged 4 months to 12 years, who underwent tethered cord release for either a thickened filum terminale and/or a low-lying conus. For intraoperative monitoring, we utilized electrical stimulation of the filum terminale, lumbosacral nerve roots and electromyography recordings. Ventral nerve roots were identified and their electrical thresholds obtained. The mean was 0.32 V, the mode 0.1 V and the range 0.05-1.0 V. These values were compared to electrical thresholds obtained by stimulation of the filum terminale. The mean was 26.1 V, the mode 20.0 V and the range 8-100 V. In over 70% of patients, muscle activation via the filum required 100 times the voltage needed to activate a motor root. This motor root to filum threshold of 1:100 was useful in identifying the filum. Clinical outcome showed no significant worsening with respect to bowel and bladder control or pain and motor indices. Significant bowel and bladder improvement was seen in 4 out of 25 patients, motor improvement in 9 out of 25 patients and improvement of pain in 4 out of 25 patients. Three patients developed postoperative urinary tract infections, but no cerebrospinal fluid leaks or pseudomeningoceles were encountered. These results suggest that patients with a thickened filum or low-lying conus can safely undergo tethered cord release. Intraoperative neurophysiological monitoring provides a helpful adjunct to distinguish nerve roots from the filum. A ratio, rather than an absolute number, is beneficial in distinguishing motor roots from the filum and eliminates variability due to patients' individual differences in electrical thresholds.