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Object The purpose of this study was to report the results of a survey of the American Society of Pediatric Neurosurgeons (ASPN) on treatment of Chiari malformation Type I (CM-I) with syringomyelia. Methods A questionnaire was circulated during the 2006 meeting of the ASPN, in which surgeons were surveyed on their management of patients with CM-I and syringomyelia. The survey consisted of questions about 4 clinical scenarios, common causes of surgical failures, and complications. Results There were 72 respondents, representing more than 90% of attendees at the 2006 ASPN meeting and approximately half of the society's members. The majority of respondents (85%) reported that they perform posterior fossa decompression as first-line treatment for CM-I with syringomyelia. Seven percent perform bony decompression alone, 36% open the dura, and 27% shrink the tonsils. Very few respondents indicated that they offer syrinx drainage as first-line therapy (< 3%). Although all respondents reported that they treat symptomatic CM-I/syringomyelia patients surgically, 15% of respondents indicated that they do not operate on asymptomatic patients. Finally, respondents stated that their most common complications are pseudomeningocele and chemical meningitis. Conclusions This survey, given to a representative group of experienced North American pediatric neurosurgeons, confirms that posterior fossa decompression is still the preferred treatment modality in children with CM-I and syringomyelia, regardless of symptoms. Although most surgeons open the dura, preferred techniques for decompression vary. In contrast to the results of past surveys, conservative follow-up is now only used by a minority of respondents and only in the asymptomatic patient, and primary syrinx drainage seems to have lost popularity. A multicenter trial of surgical outcomes has been designed based on the information from this survey.

The purpose of this article is to provide insight into the development of surgery for acoustic neurinomas throughout the years. The significant contribution of surgical authorities such as Cushing, Dandy, and House are discussed. The advances in surgical techniques from the very first operations for acoustic tumors at the end of the 19th century until today are described, with special emphasis on the technological and diagnostic milestones that preceded each step of this development.

✓ A case report of monostotic fibrous dysplasia of the clivus in a postadolescent woman is described. Although fibrous dysplasia of craniofacial structures is well documented, involvement of the clivus has not been reported. Diagnosis by clinical, radiographic, and histopathological features is detailed. Implications for the role of surgery and management are discussed.

Object Patients with posterior fossa arteriovenous malformations (AVMs) are more likely to present with hemorrhage than those with supratentorial AVMs. Observed patients subject to the AVM natural history should be informed of the individualized effects of AVM characteristics on the clinical course following a new, first-time hemorrhage. The authors hypothesize that the debilitating effects of first-time bleeding from an AVM in a previously intact patient with an unruptured AVM are more pronounced when AVMs are located in the posterior fossa. Methods The University of California, San Francisco prospective registry of brain AVMs was searched for patients with a ruptured AVM who had a pre-hemorrhage modified Rankin Scale (mRS) score of 0 and a post-hemorrhage mRS score obtained within 2 days of the hemorrhagic event. A total of 154 patients met the inclusion criteria for this study. Immediate post-hemorrhage presentation mRS scores were dichotomized into nonsevere outcome (mRS ≤ 3) and severe outcome (mRS > 3). There were 77 patients in each group. Univariate and multivariate logistic regression analyses using severe outcome as the binary response were run. The authors also performed a logistic regression analysis to measure the effects of hematoma volume and AVM location on severe outcome. Results Posterior fossa location was a significant predictor of severe outcome (OR 2.60, 95% CI 1.20–5.67, p = 0.016) and the results were strengthened in a multivariate model (OR 4.96, 95% CI 1.73–14.17, p = 0.003). Eloquent location (OR 3.47, 95% CI 1.37–8.80, p = 0.009) and associated arterial aneurysms (OR 2.58, 95% CI 1.09, 6.10; p = 0.031) were also significant predictors of poor outcome. Hematoma volume for patients with a posterior fossa AVM was 10.1 ± 10.1 cm3 compared with 25.6 ±28.0 cm3 in supratentorial locations (p = 0.003). A logistic analysis (based on imputed hemorrhage volume values) found that posterior fossa location was a significant predictor of severe outcome (OR 8.03, 95% CI 1.20–53.77, p = 0.033) and logarithmic hematoma volume showed a positive, but not statistically significant, association in the model (p = 0.079). Conclusions Patients with posterior fossa AVMs are more likely to have severe outcomes than those with supratentorial AVMs based on this natural history study. Age, sex, and ethnicity were not associated with an increased risk of severe outcome after AVM rupture, but posterior fossa location, associated aneurysms, and eloquent location were associated with poor post-hemorrhage mRS scores. Posterior fossa hematomas are poorly tolerated, with severe outcomes observed even with smaller hematoma volumes. These findings support an aggressive surgical posture with respect to posterior fossa AVMs, both before and after rupture.

✓ A new method for evaluating the patency of a ventriculoatrial shunt is described, and early experience with it is reported. Transesophageal echocardiography can demonstrate a cerebrospinal fluid leak in the right atrium through the atrial tip of a shunting device. This capability was an incidental discovery, and since then the accuracy of the technique in evaluating the patency of a ventriculoatrial shunt has been prospectively studied in 20 observations of 16 patients. The method proved to be accurate in 90% to 100% of cases. It is concluded that transesophageal echocardiography offers a rapid and accurate assessment of ventriculoatrial shunt function, is well tolerated, and is easy to perform.

✓ The author presents a long-term follow-up report of his experience with decompression of the posterior trigeminal root in 350 cases. He has found that the suboccipital approach results in fewer recurrences of pain than the temporal approach.

✓ A large subdural xanthogranuloma was removed from the posterior fossa of a 53-year-old woman with symptoms of Hand-Schüller-Christian disease. Two additional masses with similar density on computerized tomography were found in the hypothalamus and in the choroid plexus of the right lateral ventricle.

✓ Seventeen ventriculograms with the non-ionic water-soluble contrast medium, metrizamide, were performed in 15 patients, with negligible adverse effects. Visualization of the ventricular system was good in most of the patients. A combined technique, using both metrizamide and gas, increased the diagnostic value of the procedure in some cases.

✓ A series of 20 cases of arachnoid cysts in the posterior fossa is reported. Classification was made according to the location of the cysts. Accurate clinical localization was only possible with cysts in the cerebellopontine angle. Ventriculography and pneumoencephalography were the most helpful investigations for making the diagnosis. Treatment consisted of suboccipital craniectomy and complete removal. There were four operative deaths. The remaining 16 patients had essentially complete recoveries.

T HE first report of multiple intracranial meningiomas in 1889 by Anfimow and Blumenau I aroused interest which is still current in the problem of multiple brain tumors. Recently, Levin, et al.2 collected 92 such cases, the rate of multiplicity being approximately 2 .3%. The following case of a patient with two intracranial and one spinal cord meningiomas is unique in that the three large tumors occupied separate neuraxial compartments, the cranial vault, posterior fossa, and the spinal canal, and matured symptomatically almost simultaneously.

✓ The author reports the safe and satisfactory use of Conray ventriculography in 26 patients with increased intracranial pressure and discusses his technique for this procedure.