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Background: Intracranial cerebrospinal fluid (CSF) volume depletion causes diverse clinical syndromes most of them constituting the manifestations of decreased intracranial pressure. Subdural collections or chronic subdural hematomas are the best-known consequences of persistent CSF leaks, especially in overshunted hydrocephalus. Continuous CSF escape also occurs after lumbar puncture, spinal anesthesia, and diverse spinal surgeries., Case Description: A 6-year-old boy submitted to reoperation of spinal cord compression due to partial sacral agenesis complained of postoperative orthostatic headaches and vomiting initially attributed to CSF hypotension. There were neither subcutaneous fluid accumulations nor CSF leakage from the wound. The child was treated with strict bed rest and intravenous hydration for 5 days. On reassuming orthostatism, the patient had syncope but did not hit his head. A cranial computerized tomography scan showed an acute subdural hematoma that was managed conservatively with total recovery., Discussion and Conclusion: A review of current literature showed scanty reports of acute intracranial bleeding occurring after CSF depletion following spinal surgical procedures. To our knowledge, our reported patient represents the second case of this occurrence following surgery for closed spinal dysraphism in a child. The authors briefly review documented instances of acute subdural hematoma following spinal procedures, advise about its diagnosis, and suggest preventive measures.

Background: Cerebrospinal fluid (CSF) overdrainage in hydrocephalus is well recognized. Overshunting following cysto-peritoneal (CP) drainage in patients with arachnoid cysts (AC) is rarely documented., Aim: We report five patients with acquired Chiari malformation I and three with posterior fossa overcrowding due to excessive CSF drainage in shunted intracranial ACs. We review our observations and discuss the current knowledge on the pathogenesis and management of this complication., Patients and Methods: The medical records of the eight patients were analyzed in regard to clinical manifestation, cyst and shunt characteristics, management, and outcomes., Results: Mean age of the patients was 5.5 years. After an average interval of 5 years, five patients developed symptoms related to hindbrain herniation and three to severe shunt overdrainage following CP shunting. Several management modalities were utilized that achieved a good result in seven instances., Discussion: Some shunted ACs may evolve with overdrainage syndromes. Posterior fossa overcrowding and tonsillar herniation constitute their most severe forms. CSF hypotension, bone changes, venous engorgement, and probably cerebral chronic edema at the posterior fossa constitute the main factors involved in the pathogenesis of this entity. We also review previous instances of acquired Chiari malformation originating after AC shunting., Conclusions: Posterior fossa overcrowding and acquired Chiari I malformation can develop after excessive CSF drainage of intracranial ACs. Overshunting manifestations require prompt recognition and management. Preventive measures consist of making a stringent selection of cases being considered for surgery, avoiding CP drainage, and placing of a programmable valve as initial treatment of intracranial ACs if shunting is considered.

Case: A 3-year-old boy underwent emergency external ventricular drainage and excision of a fourth ventricle anaplastic ependymoma. A week later, the child was given a ventriculo-peritoneal shunt. Fourteen days after shunting, the child developed a subphrenic abscess and acute cholecystitis that required surgery., Results: A Staphylococcus epidermidis was isolated both from the ventricular catheter and CSF and from the subphrenic abscess and the gallbladder. To our knowledge, this is the first report of cholecystitis evolving as a descending shunt infection. The current literature related with this unique complication is briefly reviewed.

Two patients with intracranial arachnoid cysts, one with myelomeningocele-hydrocephalus and the other with a subdural fluid collection, were given a cerebrospinal (CSF) extracranial shunt. All four patients developed features of CSF overdrainage following shunting and were treated by cranial vault expanding procedures. Before undergoing decompressive craniotomy, the patients were treated by a variety of procedures, including changing of obstructed ventricular catheters (n=4), insertion or upgrading of programmable valves (n=3), and foramen magnum decompression (n=1). Clinical manifestations of these four patients were attributed to craniocerebral disproportion caused by chronic and progressive skull changes due to dampening of the CSF pulse pressure, which is necessary for maintaining normal cranial growth. On the basis of our previous experience with expanding craniotomies in cases of minimal forms of craniosynostosis, we treated these patients with bilateral parietal craniotomies, with satisfactory results. In conclusion, biparietal decompressive craniotomy constitutes a useful and safe procedure for relieving the clinical manifestations of some CSF overdrainage syndromes, especially in cases with slit-ventricle syndrome and craniocerebral disproportion that prove to be refractory to simpler management procedures.

Objectives: To assess the incidence and characteristics of postoperative changes in the higher cerebral functions after elective intracranial surgery under general anesthesia., Patients and Methods: This is a prospective study of 60 patients, aged 18-81 years, submitted to neurosurgical operations, allocated into two groups of 30 patients each: intracranial surgery group, patients submitted to craniotomy, and extracranial surgery group or control group, patients submitted to spinal procedures. All patients were given the Abbreviated Mental Test (AMT) on the day before to the operation, and then 2 and 24 hours after the end of the procedure. All individuals were managed with the same anesthetic technique., Results: No differences in regard to demographics, duration of the operation, ASA physical state, and habits were found between the two groups. No differences in the pre-surgical and post-surgical AMT mean score were encountered between patients submitted to intracranial 9.87 +/- 0.35 or to spinal surgeries 9.80 +/- 0.41. Similarly, there were no significant differences between the two groups in the results of the AMT performed at 2 and 24 hours after the end of the surgeries. Only two subjects undergoing spinal procedures had a score of < or = 8 in the AMT performed 2-hours after the operation, while none showed a decrease in the 24-hour test score., Conclusions: Patients submitted to intracranial surgery did not show any changes in cognitive or attention functions during the first postoperative 24 hours as assessed by the AMT.

Overdrainage in ventricular shunting constitutes a difficult to prevent and to treat complication. The authors reviewed a retrospective series of 512 children submitted to a ventricular shunting procedure aimed at analysing factors influencing this type of complication. The causes for the hydrocephalus were congenital (n=172), post-myelomeningocele (n=123), posthemorrhagic (n=103), tumoral (n=64), postmeningitis (n=40) and posttraumatic (n=10). Eighty-eight children (17.8%) evolved with a complication related to the excessive function of the valve. The authors investigated the relationship between hydrocephalus' etiology and type of overdrainage syndromes. The most frequent complication was ventricular catheter block (n=50), followed by symptomatic slit ventricle syndrome (SVS) (n=19), subdural hematoma (n=10) and trapped fourth ventricle (n=9). There were no statistical differences regarding complications for each etiologic subset of hydrocephalus. SVS occurred in 19 children (3.71%), a low rate according to the current literature. Posthemorrhagic and postinfectious hydrocephalus grouped together showed a higher rate of SVS (p=0.005), a feature that we attributed to the cerebral destruction caused by these two conditions. Treatment of SVS was complex and required diverse procedures, applied in an escalated way, which included five decompressive craniectomies. The authors suggest avoiding, as much as possible, the use of ventricular shunts, and recommend the alternative use of new technology valves and neuroendoscopic procedures.

Tension pneumocephalus is a rare and severe complication appearing after posterior fossa procedures in the sitting position. This complication may endanger the patient's life and require immediate treatment. However, tension pneumocephalus after neurosurgical procedure in the supine position have been scarcely reported. We report such a complication occurring in a 14-year-old girl submitted to a frontotemporal craniotomy for removal of an astrocytome performed with the patient supine. We discuss ethiopathogenesis and management of this complication.

Objective: Pneumocephalus is a well-known complication of surgical procedures performed with the patients placed in the sitting position. Its incidence and intensity were prospectively studied in 90 consecutive patients undergoing a posterior fossa procedure in this position. Various anesthetic agents, with different effects on cerebral hemodynamics, were used., Material and Methods: Patients were randomly assigned to one of three groups. In group 1 (n=30), anesthesia was induced and maintained with propofol. In group 2 (n=30), anesthesia was induced with thiopental and maintained with isoflurane. In group 3 (n=30), anesthesia was induced with thiopental and maintained with nitrous oxide and low-dose isoflurane. All patients received a load dose and an infusion of fentanyl. A cerebral computed tomography scan was performed to all patients 8 hours after surgery for detecting the presence and location of intracranial air. The size of pneumocephalus was ascertained using the formula for calculating the volume of a spheroid: v = PI / 6. x. y. z. Preoperative diagnosis, existence of shunted or non-shunted hydrocephalus, type and duration of the surgical procedure, detection of intraoperative venous air embolism, and appearance of new neurological symptoms in the postoperative period, were recorded., Results: All patients included in the study developed postoperative pneumocephalus. There were no significant differences (P = 0.133) in the estimated volume of intracranial air between the groups (group 1, volume = 38.3 -/+ 35.4 ml; group 2, volume = 48.9 -/+ 36.3 ml; group 3, volume = 31.5 -/+ 28.4 ml). Only two patients in the group 2 manifested symptoms of neurological involvement due to the pressure exerted by the intracranial air., Conclusions: Despite the hypothetical diverse effects of the three anesthetic techniques used in this series on cerebral hemodynamics, our results suggest that none of them has a substantial effect on the amount of intracranial air detected after posterior fossa procedures performed in seated individuals. To the best of our knowledge this is the first report that addresses in a prospective manner the effects of several habitual anesthetic techniques on the development of pneumocephalus in patients submitted to posterior fossa procedures performed in the sitting position.

Introduction: Ventriculoatrial and ventriculopleural shunts (VPS) are alternatives to ventriculoperitoneal shunts for draining cerebrospinal fluid from patients with hydrocephalus. VPS has seldom been used because of the risk of respiratory insufficiency due to pneumothorax or pleural effusion. However, valves are currently available with anti-siphon devices for use with standard shunting systems to prevent the development of pleural effusion. The aim of this study was to analyze outcome after VPS in eight patients in whom we used the new valves for avoiding overdrainage of cerebrospinal fluid., Material and Method: Nine VPS procedures were performed in eight hydrocephalic patients between 1988 and 2000. We used differential pressure valves in eight procedures and a flow regulator valve in one. The externally adjustable Sophy valve was used in six cases. The indication for VPS was peritoneal adhesions in four cases, persistent ascites in two, ventriculoatrial valve obstruction in one, and infection of the peritoneal shunt (peritonitis) in one. The ninth case involved replacement of a previously obstructed valve., Results: After a follow-up period of 22 months all shunts were functioning well and the only patient with symptoms of hydrocephalus was the one who required valve replacement at six months. No surgical morbidity or mortality was observed, and only one patient developed transitory signs of excessive cerebrospinal fluid drainage, which was corrected by regulating the magnetic valve gradient. The death of one patient 36 months after surgery was unrelated to pleural drainage., Conclusions: Valves newly designed to prevent overdrainage of cerebrospinal fluid give satisfactory results, such that VPS should be considered as an alternative to peritoneal drainage.

A 10-year-old boy underwent a posterior fossa craniectomy for removal of a grade 2 cerebellar astrocytoma. Dural closure was achieved by the placement of a dural graft. Eight years later the patient developed dementia and myoclonus. Electroencephalography demonstrated generalized slow activity that evolved into a pattern of periodic triphasic waves. Computed tomography scan and magnetic resonance imaging were unremarkable. Brain biopsy confirmed spongiform encephalopathy of the Creutzfeldt-Jakob type. In the light of previous reports of four similar occurrences, and of our own experience with two further cases of this disease, we believe that the cadaveric dura was the source of transmission of Creutzfeld-Jakob disease in our patient. The authors remark the importance of the awareness of this late complication of dural substitutes, both for the diagnosis of possible future cases and for taking preventive measures to stop the spread of the disease.