Hydrocephalus after subarachnoid hemorrhage:A metaanalytic comparison of aneurysm treatments

AIM: To compare two treatments for ruptured cerebral aneurysm with reference to the relative risk of developing hydrocephalus.METHODS: We reviewed the English language literature on the risk of developing hydrocephalus after aneurysm treatment.Data were divided by type of study(randomized controlled trial,cohort trial,nonrandomized comparison,prospectively- and retrospectively-collected observational study).They were also divided by type of aneurysm treatment(microvascular- clipping,or endovascular- coiling).Additional predictive variables collected for each publication were average age,gender distribution,measures of hemorrhage volume and subarachnoid hemorrhage severity,aneurysm locations,time to treatment,duration of follow-up and date of publication.We employed meta-analysis to calculate pooled risk ratios of developing hydrocephalus in cases receiving aneurysm clipping vs those receiving coiling.Meta-regression was used to correct pooled results for covariates.RESULTS: Because indications for the two treatments are different,there is little clinical equipoise for treating most cases.The single randomized,controlled trial dealt with a small subset of ruptured aneurysms.Neither this nor pooled values from other studies which compared the two treatments had the power to demonstrate significant differences between the two treatments.Nor was there an apparent difference when observational data were meta-analytically pooled.However,when meta-regression was used to correct for predictive variables known to differ between the two treatment groups,a highly-significant difference appeared.Coiling is used more commonly in older,sicker patients with aneurysms in certain locations.These cases are more likely to develop hydrocephalus.When corrected for these covariates,the risk of hydrocephalus was found to be significantly lower in coiled vs clipped cases(P = 0.014).CONCLUSION: Pooled observational data were necessary to demonstrate that coiling ruptured cerebral aneurysms is associated with a lower risk of developing hydrocephalus than is clipping.

Chordomas and Their Consideration in the Radiographic Differential of Extra-Axial Lesions of the Central Nervous

Due to the rare occurrence of chordomas extra-axially, these lesions have not earned a great deal of consideration in the clinical and radiographic differential diagnoses of extra-axial paraspinal lesions. We describe a case of a patient with a surgically resected extra-axial chordoma and review the radiologic characteristics of chordomas as an entity in the spectrum of extra-axial lesions. A 47-year-old man presented to our institution with four months of intermittent parethesias, pain, and subjective weakness in the left leg. MR imaging of the lumbar spine demonstrated a large heterogeneously- enhancing paraspinal lesion extending from the left L3-4 neural foramen into the psoas muscle. The patient underwent a CT-guided needle biopsy demonstrating features consistent with a chordoma. He then underwent a left retroperitoneal approach and en bloc resection of the lesion from the vertebral column. Pathology confirmed chordoma as the diagnosis. EACs are a rare but important consideration in the diagnosis of extra-axial lesions of the central nervous system.