Le retour veineux sanguin cérébral

It is generally assumed that the jugular veins are the only significant path for cerebral venous drainage. Little attention has been given to the possible role of other venous paths for the cerebral venous outflow. In fact, the meningorachidian venous plexus acts as the major outflow tract of cerebral circulation in the upright position. This phenomenon is linked with postural variations in cerebrospinal fluid pressure. It is difficult to assess the significance of this posterior venous plexus under physiopathologic conditions, which probably depends on the extent of the anastomoses between the two systems.     

Kyste hydatique rétrovésical: aspects diagnostiques et thérapeutiques

Objective: To evaluate the clinical, radiological and surgical features of retrovesical hydatid eysts and to discuss their etiology and pathogenesis.Patients and Methods: Between 1988 and 2001, 8 patients with retrovesical hydatid cysts were hospitalized and operated at the Urology Department of the Military University Hospital Mohamed V. Rabat, Morocco. The mean age of the patients was 44 years. Bladder irritation was the most frequent presenting symptom. Hydaturia was found in one ease only.Results: Cysto-pericystectomy was performed in all patients. The post-operative eourse was uneventful and only one patient developed urinary fistula which was repaired successfully.Conclusion: Retrovesical hydatid eysts are rare and treatment is mainly surgical.     

Implantation auditive du tronc cérébral chez l’enfant. À propos de trois cas

Aim of the studyTo present three pediatric cases of auditory brainstem implantation (ABI) and review literature data concerning this topic.PatientsThe first two children had a neurofibromatosis type II with bilateral sensorineural deafness; in both cases, the implant was inserted during the surgical removal of a vestibular schwannoma; the third patient had profound deafness due to bilateral cochlear nerve insufficiency associated with inner ear malformation.ResultsTwo postoperative complications were observed: patient 1 had a persistent fever which required the replacement of the fat graft used to seal the translabyrinthine approach; patient 3 had a CSF leakage requiring additional surgery and lumbar external drainage. In our three patients, the numbers of active electrodes were 6/22 (Cochlear ABI 24M ABI), 11/12 (Medel Opus II ABI) and 11/12 (implant Medel), respectively. Due to additional major surgical procedures and to disappointing functional results of the ABI, patient 1 stopped wearing her implant 18 months after implantation. Nine months after surgery, patient 2 achieved open-set speech recognition and was very satisfied with the implant. Six months after implantation, patient 3 (cochlear nerve deficiency), who was 3.5 years-old at the time, clearly reacted to some environmental sounds but was not yet able to achieve speech recognition.ConclusionsABI has now entered the list of treatments that can be proposed in pediatric profound sensorineural deafness. Its major risks of complications are CSF leakage and non-auditory side effects. Its outcomes are worse and less predictable than cochlear implants. Thus, its indications must remain restricted to cases meeting the following conditions: absence of alternative option to restore hearing, patients and parents high level of motivation and realistic expectations.     

Thérapie génique du glioblastome cérébral par vecteur adénoviral. Modèle expérimental chez le rat

Our aim was to test the therapeutic effects of adenovirus-mediated gene therapy in an animal brain tumor model which was obtained by stereotactic injection of 9L gliosarcoma cells into the caudate nucleus of rat brains. Seven days after the implantation of tumor cells, adenovirus vectors bearing the Escherichia coli β-galactosidase gene (ADVbgal) or the herpes simplex virus thymidine kinase gene (ADVtk) were stereotactically injected into the tumor. Injection of the ADVbgal resulted in the expression of the marker gene in 11 animals. Transfer of the ADVtk was followed, 3 days later, by intraperitoneal injection of ganciclovir (GCV) for 10 days. A control group was treated with saline instead of GCV. We observed a significant regression of the tumors in the rats treated with ADVtk and GCV as compared with control animals. In four cases the tumor completely disappeared after treatment. These results demonstrate the potential efficacy of adenovirusmediated transfer of the HSVtk gene following by GCV administration for the treatment of glioblastomas.