ObjectivesTo investigate whether gravitational valves reduce the risk of overdrainage complications compared with programmable valves in ventriculoperitoneal (VP) shunt surgery for idiopathic normal pressure hydrocephalus (iNPH).BackgroundPatients with iNPH may benefit from VP shunting but are prone to overdrainage complications during posture changes. Gravitational valves with tantalum balls are considered to reduce the risk of overdrainage but their clinical effectiveness is unclear.MethodsWe conducted a pragmatic, randomised, multicentre trial comparing gravitational with non-gravitational programmable valves in patients with iNPH eligible for VP shunting. The primary endpoint was any clinical or radiological sign (headache, nausea, vomiting, subdural effusion or slit ventricle) of overdrainage 6 months after randomisation. We also assessed disease specific instruments (Black and Kiefer Scale) and Physical and Mental Component Scores of the Short Form 12 (SF-12) generic health questionnaire.ResultsWe enrolled 145 patients (mean (SD) age 71.9 (6.9) years), 137 of whom were available for endpoint analysis. After 6 months, 29 patients in the standard and five patients in the gravitational shunt group developed overdrainage (risk difference −36%, 95% CI −49% to −23%; p<0.001). This difference exceeded predetermined stopping rules and resulted in premature discontinuation of patient recruitment. Disease specific outcome scales did not differ between the groups although there was a significant advantage of the gravitational device in the SF-12 Mental Component Scores at the 6 and 12 month visits.ConclusionsImplanting a gravitational rather than another type of valve will avoid one additional overdrainage complication in about every third patient undergoing VP shunting for iNPH.

The management of colloid cyst remains controversial, evaluation of the competing methods seems to be necessary. We report on our experience with colloid cysts in the last decade: ten were managed solely endoscopically, 10 were resected microsurgically (9 via a transcortical/transventricular, 1 via a transcallosal approach). The outcome in the endoscopic group was excellent in 9 cases and unsatisfying in 1 case (recurrence). In the microsurgical group we achieved a good outcome in 5 of 10 cases, a fair outcome in 4 cases and 1 lethal outcome (caused by pulmonary embolism). Complications in the endoscopic group: one intraoperative bleeding, 1 stitch granuloma, 1 mispuncture of the ventricle, and 1 meningitis. Complications in the microsurgical group: 1 subdural effusion, 1 flap infection, 1 mild hemiparesis, 1 transient impairment of consciousness and 1 pulmonary embolism. Mean operative time and length of hospitalization of the endoscopic group were clearly shorter than in the microsurgical group: 91 min versus 267 min time of surgery, 5.1 days versus 18.9 days of hospitalization. Complete resection was achieved in 8 of 10 cases of microsurgery, and in 3 of 10 cases in endoscopy. Endoscopic management results in lower costs and superior patients' comfort. The reduced number of total resections in the endoscopic group may lead to a higher recurrence rate in long-term follow-up, which might be a serious disadvantage of endoscopy. However, more experience in the endoscopic techniques may result in a higher rate of total resection of colloid cysts.

The basis of successful 3rd ventriculostomy in cases of communicating hydrocephalus is not yet understood. We performed 3rd ventriculostomies in 5 patients with free cerebrospinal fluid (CSF) communication from the ventricles to the cisterna magna. Preoperative magnetic resonance images (MRIs) showed dilated ventricles, a downward bulging floor of the 3rd ventricle (interpreted as a sign of pressure gradient between the ventricles and basal cisterns) and a free communication to an enlarged cisterna magna. The other basal cisterns were of normal or smaller size. All patients recovered from their clinical symptoms and none of them needed a shunt. The hypothesis of an intracisternal CSF pathway obstruction (e.g. between the cisterna magna and the prepontine cistern) could explain the MRI findings, although such an obstruction cannot be directly visualized. It would also explain the successful 3rd ventriculostomies in these cases.

Aneurysms originating from perforatoring branches of the midbasilar artery are extremely rare. Rupture of such an aneurysm resulted in a subarachnoid hemorrhage with a prepontine clot in a 44 year old male who presented with an acute confusional state. After coil embolization had failed, the partially thrombosed aneurysm was wrapped and coagulated via a combined supra-/infratentorial subtemporal presigmoid approach in prone position. The postoperative course was complicated by a tension pneumatocephalus and liquorrhea. Additional aneurysms of the anterior communicating artery and right middle cerebral artery were clipped several months later. The patient recovered well, and except for slight gait ataxia no other deficit remained.