Joel C. Boaz

Origin of Organisms Infecting Ventricular Shunts

&NA; Results of skin cultures obtained before 413 of 505 operations for cerebrospinal fluid‐diverting ventricular shunt placement or revision in a pediatric population from April 1980 to May 1983 are analyzed and compared to results of cultures from 20 subsequent shunt infections. Sensitivities to 11 different antibiotics were determined for each isolate cultured. The total operative infection rate was 20 of 505 (4%). Gram‐negative bacilli alone accounted for 3 of 20 (15%) shunt infections. One gram‐negative bacillus/Staphylococcus aureus infection occurred. Factors predisposing for gramnegative bacillus shunt infection were found in all 4 cases. The majority of shunt infections were caused by typical resident skin organisms: Staphylococcus epidermidis alone, 9/20 (45%); Staphylococcus aureus alone, 4/20 (20%); Corynebacterium sp., 1/20 (5%); &agr;‐Streptococcus with S. epidermidis, 1/20 (5%); and Micrococcus with S. epidermidis, 1/20 (5%). Only 4 (20%) of the 20 shunt infections were due to organisms identical to those originally grown from the skin. Another 4 (20%) seemed to be infected with a strain of organism different from that initially recovered from the skin. The remaining skin organism shunt infections may or may not have come from the patients skin. The data suggest that not all skin organism shunt infections arise from contamination by resident skin bacteria at the incision sites at the time of operation. Alternate sources for the infecting organisms are discussed. The antibiotic sensitivity data on skin isolates and shunt isolates suggest that vancomycin is the antibiotic best suited for prophylaxis against shunt infection at our institution.

Primary Central Nervous System Malignant Rhabdoid Tumor: CT and MR Appearance Simulates a Primitive Neuroectodermal Tumor

Malignant rhabdoid tumor was originally described and is most commonly reported in the kidney [1-5]. A case of primary central nervous system malignant rhabdoid tumor is presented. The clinical and pathologic findings are presented and the computed tomography and magnetic resonance imaging findings are described.

Ventricular gallbladder shunts: An alternative procedure in hydrocephalus

Hydrocephalus is a frequently encountered problem in infancy and is most commonly treated by placement of ventriculoperionteal (VP) or ventriculoatrial (VA) shunts. Other sites for insertion of the distal shunt have included the stomach, ureter, and fallopian tube. This report describes an experience with ventricular gallbladder shunts (VGB) in 25 children performed from 1970 to 1985. There were 13 girls and 12 boys ranging in age from 6 months to 16 years. Diagnosis included meningomyelocoele (7), congenital hydrocephalus (7), postmeningitic complications (5), intracranial tumor (4), and intraventricular hemorrhage (2). Indications for operation included VP shunt infection (15), massive ascites following VP shunt (3), VA shunt infection (4), and distal shunt malfunction due to fibrinous adhesions or cysts (secondary to infection; (3). Three patients had early shunt failure due to proximal obstruction (2) and gallbladder atony (1). Shunt revision was required in two and the atony was successfully treated with cholecystokinin in one. Fourteen shunts remain in place, two patients have been lost to follow-up, and three children died from unrelated causes. Seventy percent of the 20 patients available for long-term follow-up have functional shunts in place. The VGB shunt procedure remains an attractive alternative for patients with hydrocephalus in whom intraperitoneal and intravascular shunts are no longer feasible.

Analysis of the risk of shunt failure or infection related to cerebrospinal fluid cell count, protein level, and glucose levels in low-birth-weight premature infants with posthemorrhagic hydrocephalus

OBJECT Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt obstruction and infection. Established risk factors for shunt failure include grade of the hemorrhage and age at shunt insertion. There is anecdotal evidence that the amount of red blood cells or protein levels in the CSF may affect shunt performance. However, this has not been analyzed specifically for this cohort of high-risk patients. Therefore, the authors performed this study to examine whether any statistical relationship exists between the CSF constituents and the rate of shunt malfunction or infection in this population. METHODS A retrospective cohort study was performed on premature infants born at Riley Hospital for Children from 2000 to 2009. Inclusion criteria were a CSF sample analyzed within 2 weeks prior to shunt insertion, low birth weight (< 1500 grams), prematurity (birth prior to 37 weeks estimated gestational age), and shunt insertion for posthemorrhagic hydrocephalus. Data points included the gestational age at birth and shunt insertion, weight at birth and shunt insertion, history of CNS infection prior to shunt insertion, shunt failure, shunt infection, and the levels of red blood cells, white blood cells, protein, and glucose in the CSF. Statistical analysis was performed to determine any association between shunt outcome and the CSF parameters. RESULTS Fifty-eight patients met the study entry criteria. Ten patients (17.2%) had primary shunt failure within 3 months of insertion. Nine patients (15.5%) had shunt infection within 3 months. A previous CNS infection prior to shunt insertion was a statistical risk factor for shunt failure (p = 0.0290) but not for shunt infection. There was no statistical relationship between shunt malfunction or infection and the CSF levels of red blood cells, white blood cells, protein, or glucose before shunt insertion. CONCLUSIONS Low-birth-weight premature infants with posthemorrhagic hydrocephalus have a high rate of shunt failure and infection. The authors did not find any association of shunt failure or infection with CSF cell count, protein level, or glucose level. Therefore, it may not be useful to base the timing of shunt insertion on CSF parameters.

Phosphorus-32 therapy for cystic craniopharyngiomas

BACKGROUND AND PURPOSE To examine control rates for predominantly cystic craniopharyngiomas treated with intracavitary phosphorus-32 (P-32). MATERIAL AND METHODS 22 patients with predominantly cystic craniopharyngiomas were treated at Indiana University between October 1997 and December 2006. Nineteen patients with follow-up of at least 6 months were evaluated. The median patient age was 11 years, median cyst volume was 9 ml, a median dose of 300 Gy was prescribed to the cyst wall, and median follow-up was 62 months. RESULTS Overall cyst control rate after the initial P-32 treatment was 67%. Complete tumor control after P-32 was 42%. Kaplan-Meier 1-, 3-, and 5-year initial freedom-from-progression rates were 68%, 49%, and 31%, respectively. Following salvage therapy, the Kaplan-Meier 1-, 3-, and 5-year ultimate freedom-from-progression rates were 95%, 95%, and 86%, respectively. All patients were alive at the last follow-up. Visual function was stable or improved in 81% when compared prior to P-32 therapy. Pituitary function remained stable in 74% of patients following P-32 therapy. CONCLUSIONS Intracystic P-32 can be an effective and tolerable treatment for controlling cystic components of craniopharyngiomas as a primary treatment or after prior therapies, but frequently allows for progression of solid tumor components. Disease progression in the form of solid tumor progression, re-accumulation of cystic fluid, or development of new cysts may require further radiotherapy or surgical intervention for optimal long-term disease control.

Chiari III malformation treated with CSF diversion and delayed surgical closure

Chiari III malformations are extremely rare hindbrain malformations that are associated with a high early mortality rate, or severe neurologic deficits in the survivors. The preferred treatment is early operative closure and CSF shunting. We report a case of a newborn infant with a Chiari III malformation with displacement of the brainstem and cerebellum into the cervical encephalocele which precluded immediate operative closure of the defect. Instead, a ventriculoperitoneal shunt was placed and the patient was followed with serial imaging studies. The child survived. The shunt allowed the brainstem and cerebellum to regress into the cervical spinal canal as the dilated cerebral aqueduct and fourth ventricle decompressed. A delayed closure of the cervical encephalocele was performed at 30 months of age. Cerebrospinal fluid diversion with delayed closure may be an option for large lesions.

Cerebrospinal fluid eosinophilia in children with ventricular shunts.

OBJECT Eosinophils have been reported in children with cerebrospinal fluid (CSF) shunts. The goal of this study was to describe the risk factors, relationship to infection, and clinical significance of CSF eosinophilia in a large group of shunt-treated patients. METHODS The authors performed a retrospective review of data obtained in all patients who underwent ventricular shunt placement or revision at the James Whitcomb Riley Hospital for Children between 2000 and 2004. RESULTS Eosinophils were identified during a follow-up shunt evaluation in 93 (31%) of 300 patients after initial shunt placement. Eosinophilia was statistically related to CSF extravasation (p < 0.0001), shunt infection (p = 0.031), blood in CSF (p < 0.0001), younger age at shunt insertion (p = 0.030), and the diagnosis of posthemorrhagic hydrocephalus (p < 0.0001). Patients with CSF eosinophilia had a higher risk of subsequent shunt failure (p < 0.0001). Analysis was performed using data obtained in a cohort of patients with a total of 130 shunt infections. Cerebrospinal fluid eosinophils were identified in 118 infections (90.8%). The leukocytic and eosinophilic reactions were dependent on the infecting organism. Propionibacterium acnes had a statistically lower CSF leukocyte count but higher differential percentage of eosinophils than the other common pathogens. CONCLUSIONS Cerebrospinal fluid eosinophilia is a relatively common finding in children with shunts. Patients with CSF eosinophilia had an increased risk of shunt malfunction in the present series. Eosinophilia is associated with infection, CSF extravasation, and blood in the CSF. Patients with P. acnes-induced shunt infections have higher eosinophil percentages than are found in infections associated with other common organisms. Therefore, in patients with eosinophilia, extended anaerobic culture studies should be performed with particular attention paid to searching for this pathogen.

Magnetic resonance imaging diagnosis of a cerebral aneurysm in an infant.

A posterior cerebral artery aneurysm presented as a seizure disorder in a 7-week-old infant. A small hemorrhage in the posterior thalamus was seen on CT scan. However, magnetic resonance imaging (MRI

Intracranial Masson tumor: case report and literature review

Intravascular papillary endothelial hyperplasia (IPEH) or Masson tumor has only been reported intracranially in 20 cases and can present as a congenital finding. This pathologic entity is an important diagnostic consideration when evaluating an infant with a congenital intracranial mass. We report a third case of a neonate who presented with the appearance of a metastatic brain tumor involving the orbit, sella, and cerebellum that was ultimately proven to be IPEH. A thorough literature review of IPEH is presented and we discuss this clinical entity and its management.

Role of fructose 2,6-bisphosphate in the regulation of glycolysis and gluconeogenesis in chicken liver☆

Glucagon and dibutyryl cyclic AMP inhibited glucose utilization and lowered fructose 2,6-bisphosphate levels of hepatocytes prepared from fed chickens. Partially purified preparations of chicken liver 6-phosphofructo-1-kinase and fructose 1,6-bisphosphatase were activated and inhibited by fructose 2,6-bisphosphate, respectively. The sensitivities of these enzymes and the changes observed in fructose 2,6-bisphosphate levels are consistent with an important role for this allosteric effector in hormonal regulation of carbohydrate metabolism in chicken liver. In contrast, oleate inhibition of glucose utilization by chicken hepatocytes occurred without change in fructose, 2,6-bisphosphate levels. Likewise, pyruvate inhibition of lactate gluconeogenesis in chicken hepatocytes cannot be explained by changes in fructose 2,6-bisphosphate levels. Exogenous glucose caused a marked increase in fructose 2,6-bisphosphate content of hepatocytes from fasted but not fed birds. Both glucagon and lactate prevented this glucose effect. Fasted chicken hepatocytes responded to lower glucose concentrations than fasted rat hepatocytes, perhaps reflecting the species difference in hexokinase isozymes.