A concerted effort to prevent shunt infection.

In an attempt to reduce the rate of shunt infection a new protocol for shunt surgery was introduced on July 1, 1988 at The Hospital for Sick Children in Toronto. The operations were done at the beginning of the day, operating room personnel were kept to a minimum, no visitors were allowed in the room, a staff neurosurgeon or neurosurgical fellow attended all operations and two doses of perioperative cloxacillin 50 mg/kg were given intravenously. From July 1, 1988 to June 30, 1989 there were 576 shunt procedures on the Neurosurgical Service and 22 (3.8%) of these resulted in a shunt infection. During the preceding year (July 1, 1987 to June 30, 1988) 581 shunt operations were performed, 75 (12.9%) of which resulted in an infection (chi 2 = 29.9, P < 0.001). It appears that the introduction of this protocol for shunt surgery has helped to reduce the risk of shunt infection from 12.9% to 3.8% (a reduction of 70.5%). The rate of infection occurring after shunt revisions was not significantly different from that occurring after new shunt insertions. When the individual factors in the protocol were analyzed, the use of antibiotics and a shorter duration of surgery appeared to be related to a lower shunt infection rate.

Tonsillar herniation: the rule rather than the exception after lumboperitoneal shunting in the pediatric population.

Although the development of tonsillar herniation (acquired Chiari malformation) in association with lumboperitoneal (LP) shunting is well recognized, it has previously been considered rare. In order to ascertain the incidence of this complication after LP shunting, the authors undertook a retrospective study of all patients in whom this form of shunt had been inserted between 1974 and 1991 at The Hospital for Sick Children, Toronto. In the 143 patients, the mean age at insertion was 3.3 years and the indications for shunt placement were hydrocephalus (81%), pseudotumor cerebri (7%), cerebrospinal fluid fistula (6%), and posterior fossa pseudomeningocele (6%). The mean follow-up period was 5.7 years, during which time there was one shunt-related death due to unsuspected tonsillar herniation. Five other patients developed symptomatic tonsillar herniation treated by suboccipital decompression. Review of all computerized tomography (CT) scans not degraded by artifact showed evidence of excess soft tissue at the level of the foramen magnum in 38 (70%) of 54 patients so studied. In order to confirm that this CT finding represented hindbrain herniation, sagittal and axial magnetic resonance (MR) images were obtained for 17 asymptomatic patients and revealed tonsillar herniation (range 2 to 21 mm) in 12 (70.6%). In addition, some of these asymptomatic patients had evidence of uncal herniation and mesencephalic distortion. Similarities and distinctions are drawn between the morphological changes occurring after LP shunting and those seen in association with the Chiari I and II malformations. Although less than 5% of this study population required treatment for tonsillar herniation, the incidence of this complication was high in asymptomatic patients; MR imaging surveillance for patients with LP shunts is therefore recommended.

Detection and management of gangliogliomas in children.

Forty-two children treated for gangliogliomas were reviewed to identify the best methods of detection and management. Thirty-two of the tumors were supratentorial, four infratentorial, and six were in the spinal cord. Twenty-five patients presented with seizures; the mean duration of symptoms was 5 years in contrast to 1 year in non-seizure patients. Of 31 children studied by computed tomography (CT), calcification in the tumor lesion was found in 19. Magnetic resonance imaging (MRI) showed abnormal high-signal intensity on T2 imaging in six of eight patients. All patients underwent surgical resection and were diagnosed pathologically. Twenty-four patients had total resection, and 14 underwent temporal lobectomies including hippocampectomy. The management of this tumor remains surgical resection without the need for any adjuvant therapy.

A randomized controlled trial of perioperative rifampin/trimethoprim in cerebrospinal fluid shunt surgery.

A randomized, double-blind, placebo-controlled trial of perioperative rifampin-trimethoprim was undertaken at the Hospital for Sick Children from March 1984 to October 1987, in which 243 patients undergoing 300 cerebrospinal fluid (CSF) shunting procedures were randomized into groups including treatment with rifampin/trimethoprim and placebo, and then followed for a minimum of 2 years. Patients were stratified prior to randomization into those with and those without meningo-myeloceles having first insertions of their shunts, and those having revisions. Patients could be entered into the study more than once, but always received the same treatment regimen once allocation had taken place. Among the patients receiving antibiotics there was an infection rate of 12%, versus 19% among patients receiving placebo. Among the surgical procedures, the rates were 9% and 15%, respectively. Because these rates of infection were a substantial increase over the rate of 7.5% overall for the few years prior to implementation of the study, and well over any acceptable rate of infection, the study was stopped before statistical significance was reached. However, had the study continued, and the proportions of patients becoming infected remained constant, we would have been able to achieve a statistically significant difference in rates of infection, and therefore demonstrate a benefit of rifampin/trimethoprim as prophylaxis against shunt infection. Methodological problems encountered in this and other studies of prevention of CSF shunt infection will be discussed.

Brain tumors in children and adolescents--III. Effects of radiation and hormone status on intelligence and on working, associative and serial-order memory.

The effects on intelligence and memory of two post-surgical conditions (radiation treatment, hormone deficiency and supplementation) were explored in 46 children and adolescents with tumors in a variety of brain sites. Verbal intelligence, but not non-verbal intelligence, varied positively with age at radiation treatment. Memory for word meanings was unrelated to either radiation history or to hormone status. Severe deficits in serial position memory occurred with impaired hormone function and an older age at tumor onset. Severe deficits in working memory were associated with a history of radiation and a principal tumor site that involved thalamic/epithalamic brain regions. Radiation treatment and hormone status affect later cognitive function in children and adolescents with brain tumors. Although the greater vulnerability of the verbal intelligence of the younger radiated child and the serial order memory of the child with later tumor onset and hormone disturbances remain to be explained, and although the form of the relationship between radiation and tumor site is not fully understood, the data highlight the need to consider the cognitive consequences of pediatric brain tumors according to a set of markers that include maturational rate, hormone status, radiation history, and principal site of the tumor.

Arteriovenous malformations of the brain in children: a forty year experience.

Despite the great capacity for the pediatric brain to recover from stroke, the morbidity and mortality in children who harbor an arteriovenous malformation (AVM) remains high. This study examines the clinical data and management experience with 132 patients with brain AVM from 1949 to 1989. Although the high tendency for a childhood AVM to present with hemorrhage (79%) remained constant for the forty year study period, the associated morbidity and mortality of hemorrhage changed. The mortality rate from hemorrhage for the entire series was 25%, which was reduced from 39% to 16% after the introduction of computed tomography. The mortality from AVM hemorrhage since 1975 was dependent on location; 8 of 14 patients (57%) with a cerebellar AVM died from hemorrhage while only 2 of 44 patients (4.5%) with a cerebral hemisphere AVM died (p less than 0.0001). Sixteen children (12%) presented with a chronic seizure disorder. Surgical excision of the malformation resulted in complete seizure control off anti-convulsant medication in 73% of patients. Although 21% of patients were treated non-operatively (many with terminal poor-grade hemorrhage), 79% had a surgical procedure with total AVM excision achieved in 70 patients (53.1%). Complete AVM resection was followed by a normal neurological outcome in 47 children (67%). Most partial excisions (n = 9) and clipping of feeding arteries (n = 7) were performed in the early years of this study, and did not provide protection from rehemorrhage. Although conservative management has been advocated for selected non-hemorrhagic AVMs, we conclude that essentially all children with an AVM should be treated in order to eliminate the risk of hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracranial germ-cell tumors in children.

All patients with confirmed intracranial germ-cell tumors treated at the Hospital of Sick Children during the period January, 1952, to December, 1989, were reviewed. Of the 51 tumors reviewed, 16 were located in the suprasellar region, 32 in the pineal region, and three in both the pineal and the suprasellar regions. Forty-nine patients underwent surgical resection which was total in seven and partial in 20, and consisted of a biopsy in 22. Two patients were managed on the basis of serum and cerebrospinal fluid markers. Surgical tools such as the operating microscope, the ultrasonic surgical aspirator, and the laser beam allowed safe debulking and removal of the deep-seated tumors in the pineal region. There were no operative deaths in the 36 patients treated since 1972, who included 23 with pineal tumors. Twenty-five patients with germinomas received radiotherapy and had a 5-year survival rate of 85.1%. Thirteen patients with non-germinoma germ-cell tumors received radiotherapy and had a 5-year survival rate of 45.5%. On the basis of this review, the authors recommend resection of pineal and suprasellar germ-cell tumors in order to firmly establish an accurate histological diagnosis to guide the extent of adjuvant therapy. In the case of a pure germinoma without evidence of dissemination, adjuvant therapy consists only of local radiotherapy. On the other hand, for malignant non-germinoma germ-cell tumors, adjuvant therapy must include chemotherapy as well as craniospinal axis radiotherapy.

Mechanical complications in shunts.

A retrospective study was conducted on 1,719 hydrocephalic patients, treated between 1974 and 1983 at the Hospital for Sick Children (Toronto) and l'Hôpital des Enfants Malades (Paris), in order to better understand shunt failure. The statistical analysis demonstrates the following: (1) A probability of occurrence of shunt malfunction of 81% at 12 years of follow-up. (2) A high prevalence of shunt obstruction (56.1% of all malfunction) and fracture or disconnection of the tubings (13.6%). (3) A higher risk of proximal occlusion with flanged ventricular catheter. (4) Less malfunction with proximal-non-slit valves as compared to distal-slit valves. (5) The importance of pressure-flow characteristics of the shunt; because of an indirect relation between overdrainage and proximal occlusion. (6) A correlation between connectors and migration or fracture of the shunt. (7) Less distal obstructions when an open-ended distal-catheter was used. These complications were of some clinical, psychological and economical consequences. Their rate could be lowed.

Brain tumors in children and adolescents--I. Effects on working, associative and serial-order memory of IQ, age at tumor onset and age of tumor.

Memory impairment was demonstrated in a sample of 46 children and adolescents with brain tumors. The overall distribution of memory scores was skewed positively; over half of the total number of test measures were in the lowest quarter of the score distribution; and more than three-quarters of the individual subjects had at least one memory score in the impaired range. Verbal intelligence accounted for less than one-quarter of the variance in memory scores. The type of memory impairment was analyzed in relation to various demographic and medical variables: age at onset of tumor symptoms, age or duration of tumor, sex, pre-tumor developmental disturbances, pre-tumor closed head injury, post-tumor anticonvulsant treatment and post-tumor epileptic seizures. The working memory task, in which each in a succession of heard words is stored in temporary memory long enough to be compared to or contrasted with incoming words, was unaffected by these variables, as was memory for semantically-based word-picture associations. Memory for the serial order of pictures that corresponded to heard words varied inversely with the age at tumor onset such that the later the onset, the lower the memory test performance.

Brain tumors in children and adolescents--II. The neuroanatomy of deficits in working, associative and serial-order memory.

The neuroanatomy of memory deficits was studied in 46 children and adolescents with brain tumors. CT-scan reconstructions of 88 brain regions were coded with respect to tumor and related damage, and multiple regression procedures established patterns of brain damage predictive of memory deficits. Two forms of memory revealed non-overlapping focal neuroanatomical substrates: memory for the serial order of pictures that corresponded to heard words involved structures in the limbic system and hypothalamic-pituitary axis; whereas working memory, in which each of a succession of heard words is stored in temporary memory long enough to be compared to or contrasted with incoming words, involved the pineal-habenular region and the anterior and medial thalamic nuclei. Memory for semantically-based word-picture associations, in contrast, was unaffected by tumors in several subcortical brain regions. These data bear on current analyses of the neural substrates of associative and representational memory.

Occult spinal dysraphism: clinical and urodynamic outcome after division of the filum terminale.

A highly select group of 31 patients presenting with urinary incontinence failed to respond to conservative management and were found to have unstable bladders and spina bifida occulta. After thorough evaluation they were suspected of having neurogenic bladder dysfunction possibly due to a tethered cord. Following division of the filum terminale daytime incontinence resolved in 72%, urodynamic detrusor hyperreflexia disappeared in 59% and bladder compliance improved in 66% of the patients. The operation was well tolerated and did not result in any neurological complications. The clinical, radiological and urodynamic characteristics of these patients before and after treatment are reported.

The head-injured child who "talks and dies". A report of 4 cases.

The phenomenon of "talking and deteriorating" after closed head injury exists in children. A variety of causes have been identified, few of which are operatively remedial. Four cases of children with head trauma are reported, in each of whom there was an interval during which the child verbalized to some degree. Rapid neurological decline then occurred approximately 30-50 h postinjury in each child, who subsequently died from their trauma. In all instances the children were injured in motor vehicle accidents or falls, had initial Glasgow Coma Scale ratings of 9 or better, and demonstrated irritability and restlessness just prior to their deterioration. In no circumstance was a space-occupying intracranial hematoma present. Post-mortem brain examinations in two of the children showed in common multiple cerebral contusions, brain edema with herniation phenomena and hypoxic-ischemic encephalopathy.

Infratentorial ependymomas in childhood: prognostic factors and treatment.

The prognostic factors and survival data were analyzed for 35 children (aged under 16 years at diagnosis) with childhood infatentorial ependymomas treated surgically at The Hospital for Sick Children in Toronto during the years 1970 to 1987. Tumor histology was reviewed individually and grouped into three categories (Categories I to III) for survival analysis. An overall 5-year survival rate of 44.6% was obtained after the exclusion of perioperative mortality. Factors associated with an improved 5-year survival rate were: total tumor removal, noninvasive tumors, Category I histology, age greater than 6 years, and absent physical signs of parenchymal invasion or lower cranial nerve involvement. The 5-year survival rate was lower when associated with Category III histology, brain-stem or cranial nerve signs, age less than 2 years, tumor invasion and/or cranial nerve involvement, and subtotal tumor removal. Clinical evidence of spinal metastases was found to be uncommon (3.1%). Surgical excision followed by radiation therapy was the primary mode of treatment for these tumors. Different approaches regarding the volume of radiotherapy to be delivered and the use of adjuvant chemotherapy are discussed.

Evaluation, surgical approach and outcome of seizure patients with gangliogliomas.

A retrospective study of 15 children with intracranial gangliogliomas and intractable seizures revealed that tumors associated with seizure were located in the temporal and frontal lobes. These patients underwent lobectomy under electrocorticography. Mesial temporal sclerosis was identified in the hippocampus of the excised temporal lobe in 7 of 13 patients with temporal lobectomies. Eleven of the 15 children were seizure-free over a mean follow-up period of 4 years. The surgical approach to gangliogliomas requires careful pre-operative evaluation, including neuroimaging and electrophysiological study to locate seizure activity. Removal of epileptogenic brain as well as the ganglioglioma is recommended to optimize seizure control.

Primary intracranial neoplasms in the first year of life.

Forty-one infants with histologically verified primary intracranial neoplasms were studied who had been diagnosed and treated during the first year of life at the Hospital for Sick Children during the years 1975-1986. Forty-one percent of tumors were astrocytomas, 22% were primitive neuroectodermal tumors, and 20% were choroid plexus papillomas. Seventy-one percent were located in the supratentorial compartment and 29% in the infratentorial compartment. Thirty percent were in the cerebral hemisphere, 12% in the optic pathway-hypothalamic region, 5% in the thalamus, 17% in the cerebellum, 5% in the brain stem, 12% in the lateral ventricles, 12% in the III ventricle, and 7% in the IV ventricle. The most common presenting features in this series of patients were vomiting and increasing head size. The symptoms and signs before diagnosis were present for 2 months or less in 87% of cases. Forty-four percent of the tumors were totally resected while only a partial resection or biopsy was carried out in 56%. Sixty-six percent of the patients required a CSF diversionary shunt. Twenty-nine percent of patients received radiotherapy. Slightly more than half of these received radiotherapy immediately after surgery, whereas delayed radiation therapy was performed in the remainder. The surgical mortality was 7.3%. Of the entire group, 39% have died, with most dying within 6 months of surgery. Treatment, survival relative to histologic type, psychomotor development, and neurologic function of the survivors are discussed.

Dandy-Walker syndrome: experience at the Hospital for Sick Children, Toronto.

Thirty-five patients with the Dandy-Walker syndrome (DWS) treated over the years 1964-1987 at the Hospital for Sick Children, Toronto, were reviewed. Thirty-three patients (94%) had hydrocephalus at the time of diagnosis. The primary association of aqueduct stenosis was excluded by radiological investigation and clinical course in all patients. Associated central nervous system (CNS) anomalies were present in 10 patients. Seven had occipital encephalocele and in 1 of these there was an associated Klippel-Feil syndrome. Four patients had agenesis of the corpus callosum and 1 patient had polyporencephaly. The treatment of these patients has changed over the years in our institution so that during an earlier period, 3 patients were treated by resection of the cyst membranes. We then went through a period of shunting the lateral ventricle so that 21 patients were treated with either a lateral ventricle to peritoneal or lateral ventricle to atrial shunt. More recently, patients with the DWS have been treated with a cyst-peritoneal shunt and 10 patients were thus treated. Only 1 patient was treated with a simultaneous lateral ventricle and cyst-peritoneal shunt. Nine of the twenty-one patients (43%) with a primary lateral ventricle to peritoneum or lateral ventricle to atrial shunt developed a secondary aqueduct stenosis and an isolated fourth ventricle which required additional cyst-peritoneal shunting. Only 1 of the 10 patients treated with a primary cyst-peritoneal shunt required an additional lateral ventricle peritoneal shunt. Two patients initially treated with a lateral ventricle peritoneal shunt and with a primary cyst-peritoneal shunt subsequently had a percutaneous stereotactic third ventriculostomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Spinal extradural arachnoid cyst.

A relatively unusual cause of progressive paraparesis is a spinal arachnoid cyst. The following is a case report of this lesion in an adolescent. The CT-myelographic and MR features, as well as the management of this case are discussed, followed by a review of the pertinent English literature on this topic.