Rapid recovery from cortical visual impairment following correction of prolonged shunt malfunction in congenital hydrocephalus.

Three children with congenital hydrocephalus are described in whom increased intracranial pressure was associated with severe, long-lasting cortical visual impairment. Following shunt revisions or reconstructive craniotomies, visual improvement began within hours. It is speculated that increased intracranial pressure can occasionally result in chronic hypoperfusion of the parietal-occipital lobes, either due to posterior cerebral artery compromise secondary to transtentorial pressure gradient or to direct compression of cerebral tissues.

Cytogenetic analysis of 109 pediatric central nervous system tumors.

Reports of cytogenetic abnormalities in pediatric central nervous system (CNS) tumors are important for collection and comparison of large numbers of karyotypes of primary CNS neoplasms to produce statistically significant correlations. We report cytogenetic results of 119 samples of pediatric CNS tumors from 109 patients. Tumors included 33 low-grade astrocytomas, 18 high-grade astrocytomas, 14 gangliogliomas, 13 ependymomas, 17 primitive neuroectodermal tumors (PNET), three choroid plexus papillomas and carcinomas, and a miscellaneous group of 20 rare primary CNS tumors and metastases. In each group, cytogenetic results were correlated with histologic subtype and survival. The study indicated specific chromosome abnormalities in different groups of tumors. Low-grade astrocytomas showed mostly numeric abnormalities with gains of chromosome 7, high-grade astrocytomas showed differences from karyotypic changes observed in adults in lacking double minutes (dmin) and monosomy 10. The ependymoma group showed the largest proportion of abnormal karyotypes with frequent involvement of chromosome 6 and 16. Chromosome 6 was the single most common abnormal chromosome in this study, closely followed by chromosomes 1 and 11. Pediatric CNS neoplasms differ from adult tumors cytogenetically as well as histologically and biologically.

The application of i.v. digital subtraction angiography to cranial disease in children.

All intracranial IV digital subtraction angiographic examinations performed over the past 2 years were reviewed retrospectively to ascertain the uses and limitations of this technique for the evaluation of pediatric intracranial disease. Of the various abnormalities studied, this imaging technique was particularly useful in diagnosing venous and dural sinus abnormalities; in screening for suspected large aneurysms, vascular malformations, and major arterial occlusive disease; and in preoperative vascular mapping. IV digital subtraction angiography has selected usefulness in confirming brain death, in evaluating cerebral ischemia, in identifying vascular abnormalities underlying intracranial hemorrhage, and in evaluating vascularity and sinus extension of masses. The IV route for digital subtraction angiography is not useful in diagnosing segmental arterial occlusive or small-vessel disease, nor is it useful in preoperative localization of specific arterial supply to arterial venous malformations, aneurysms, or neoplasms. IV digital subtraction angiography can be performed successfully in children of all ages with minimal patient morbidity. For most patients, the diagnostic information obtained was adequate without the need for standard cerebral arteriography.

Spontaneous remission of paralysis due to spinal extradural hematoma: case report.

Spontaneous spinal extradural hematoma is an uncommon cause of cord compression and paraplegia. The clinical presentation of this entity is uniform, with sudden pain followed by sensory and motor dysfunction. Unlike other considerations in the differential diagnosis of cord compression, here the pain and clinical deficit may remit suddenly and spontaneously. This feature may obscure the diagnosis of an organic cause for cord dysfunction. This report describes a patient whose extradural hematoma was caused by hemorrhage from an arteriovenous malformation. Dramatic reduction of his pain and paralysis followed myelography.

Randomized trial of cerebrospinal fluid shunt valve design in pediatric hydrocephalus.

OBJECTIVE: Forty percent of standard cerebrospinal fluid shunts implanted for the treatment of pediatric hydrocephalus fail within the first year. Two new shunt valves designed to limit excess flow, particularly in upright positions, were studied to compare treatment failure rates with those for standard differential-pressure valves. METHODS: Three hundred-forty-four hydrocephalic children (age, birth to 18 yr) undergoing their first cerebrospinal fluid shunt insertion were randomized at 12 North American or European pediatric neurosurgical centers. Patients received one of three valves, i.e., a standard differential-pressure valve; a Delta valve (Medtronic PS Medical, Goleta, CA), which contains a siphon-control component designed to reduce siphoning in upright positions; or an Orbis-Sigma valve (Cordis, Miami, FL), with a variable-resistance, flow-limiting component. Patients were monitored for a minimum of 1 year. Endpoints were defined as shunt failure resulting from shunt obstruction, overdrainage, loculations of the cerebral ventricles, or infection. Outcome events were assessed by blinded independent case review. RESULTS: One hundred-fifty patients reached an endpoint; shunt obstruction occurred in 108 (31.4%), overdrainage in 12 (3.5%), loculated ventricles in 2 (0.6%), and infection in 28 (8.1%). Sixty-one percent were shunt failure-free at 1 year and 47% at 2 years, with a median shunt failure-free duration of 656 days. There was no difference in shunt failure-free duration among the three valves (P = 0.24). CONCLUSION: Cerebrospinal fluid shunt failure, predominantly from shunt obstruction and infection, remains a persistent problem in pediatric hydrocephalus. Two new valve designs did not significantly affect shunt failure rates.

The nature of congenital posterior cervical or cervicothoracic midline cutaneous mass lesions. Report of eight cases.

Between 4% and 8% of cases of spina bifida cystica occur in a cervical or cervicothoracic location. Despite a large body of literature concerning spinal dysraphism, there has been little written specifically about patients afflicted with this disorder in a cervical location. Eight children who presented at birth with posterior cervical or cervicothoracic lumps, all of which represented a dysraphic state, are discussed. Two types of abnormalities were noted. Three patients had hydromyelia with an associated myelocystocele herniating posteriorly into a meningocele sac. In these three patients there was an associated Chiari II malformation and hydrocephalus. The other five children had a meningocele in which a band of tissue extended from the posterior aspect of the spinal cord through a defect in the bone and fascia to the posterior part of the meningocele sac itself. No patient had a lesion that could be described as a meningomyelocele. The investigation and surgical management of these conditions are discussed and the need for intradural exploration to untether the spinal cord in the cervical region is stressed.

Management of intrauterine hydrocephalus.

The aggressive treatment of hydrocephalus has been of benefit to many children. Sophisticated two-dimensional ultrasound techniques allow the diagnosis of prenatal hydrocephalus to be made with accuracy and ease. In the past, the medical decisions governing the management of hydrocephalus in utero were made by obstetricians and were directed at reducing maternal mortality and morbidity. Now, with improved diagnosis and support facilities for the newborn, neurosurgical input is being requested as more concern is expressed for the fetus. Based on their experience with seven cases of intrauterine hydrocephalus in the past 3 years, the authors present their program for the management of this problem. If antenatal ultrasonography shows hydrocephalus without other anomalies, they recommend that the fetus be born by elective Caesarean section at the time of pulmonary maturity, and that early ventricular shunting be carried out. This plan should minimize nervous system trauma resulting from hydrocephalus and the birth process. If, however, antenatal diagnostic studies show cerebral or other major system anomalies in addition to hydrocephalus, than standard obstetrical care should be given. Antenatal ultrasonography has been found to be reliable in assessing fetal lateral ventricular size and shape, and to correlate well with the results of postnatal computerized tomography scanning.

Spontaneous resolution and recurrence of a Chiari I malformation and associated syringomyelia. Case report.

The spontaneous resolution of syringomyelia has been reported infrequently. In patients with Chiari I malformations, resolution of the syringomyelia has sometimes been associated with improvement of their malformation. The authors present a case of spontaneous resolution followed by recurrence of syringomyelia and a corresponding change in the Chiari malformation. This case is of interest in light of the theories postulated to explain spontaneous resolution of syringomyelia.

The significance of bacteriologically positive ventriculoperitoneal shunt components in the absence of other signs of shunt infection.

The purpose of this study was to determine the significance of "asymptomatic bacteriological shunt contamination" (ABSC), defined as a positive bacteriological culture found on a ventricular shunt component in the absence of bacteria in the cerebrospinal fluid (CSF) culture and/or clinical evidence of infection. Of 174 ventriculoperitoneal shunt revisions, 19 cases of ABSC were identified and reviewed retrospectively. In all but one case, no antibiotic medications were instituted because of the positive bacteriological culture. The most common infecting organisms were coagulase-negative staphylococci (seven) and propionibacteria (eight). A comparison of the 19 study cases with the authors' overall shunt experience, as documented in the British Columbia's Children's Hospital shunt database for the time period of the study, lead the authors to suggest that ABSC was not of significance in causing the shunt failure at which contamination was identified and, more importantly, did not increase the risk of future shunt malfunction. The results of this study indicate that in the absence of clinical evidence of shunt infection or a positive bacteriological culture from CSF, bacteria in a shunt component removed at revision in a child almost always represents a contaminant that may be ignored. Therefore, the authors advise that routine culture of shunt components removed at revision of a shunt is not indicated.

The validity of electrophysiological criteria used in selective functional posterior rhizotomy for treatment of spastic cerebral palsy.

Although selective functional posterior rhizotomy (SFPR) is an established procedure for the treatment of spasticity, the electrophysiological criteria used to define which posterior rootlets should be cut have not been standardized. The purpose of this study was to determine the validity of the intraoperative electrophysiological criteria used to select posterior rootlets for sectioning in SFPR. Intraoperative stimulation of posterior lumbosacral nerve roots and rootlets, using a 50-Hz stimulus at threshold intensity, was performed in five nonspastic children (controls) undergoing laminectomy for spinal cord untethering and in 32 spastic patients undergoing SFPR. Electromyographic responses were recorded in the upper and lower limbs, the neck, and the face. The pattern of sustained responses was assessed in detail in 17 additional patients who had previously undergone SFPR and in the five controls. Sustained responses with ipsilateral lower limb extrasegmental spread occurred in both spastic patients and the control group. Contralateral lower limb spread and suprasegmental spread to the upper limbs, neck, and face were found only in spastic children. Sustained responses with an incremental pattern were restricted to the spastic population and correlated well with the extent of contralateral and suprasegmental spread, whereas decremental patterns were not associated with contralateral spread. It is concluded that contralateral and suprasegmental spread into the upper limbs, neck, and face, and incremental responses are probably valid criteria of abnormality.

Value of postoperative surveillance imaging in the management of children with some common brain tumors.

The rationale for obtaining surveillance computerized tomography (CT) scans or magnetic resonance (MR) images in pediatric patients with brain tumors is that early detection of recurrence may result in timely treatment and better outcome. The purpose of this study was to investigate the value of surveillance cranial images in a variety of common pediatric brain tumors managed at a tertiary care pediatric hospital. A retrospective chart review was performed of children with astrocytoma of the cerebral hemisphere, cerebellum, optic chiasm/hypothalamus, or thalamus; cerebellar or supratentorial high-grade glioma; supratentorial ganglioglioma; posterior fossa or supratentorial primitive neuroectodermal tumor (PNET); and posterior fossa ependymoma. Data were analyzed to determine the frequency with which recurrences were identified on a surveillance image and how the type of image at which recurrence was identified related to outcome. In 159 children, 17 of 44 recurrences were diagnosed by surveillance imaging. The percentage of recurrences identified by surveillance imaging was 64% for ependymoma, 50% for supratentorial PNET, 43% for optic/hypothalamic astrocytoma, and less than 30% for other tumors. The rate of diagnosis of recurrence per surveillance image varied from 0% to 11.8% for different tumor types. Only for ependymomas did there appear to be an improved outcome when recurrence was identified prior to symptoms. Our results indicate that, using the protocols outlined in this study, surveillance imaging was not valuable in identifying recurrence of cerebellar astrocytoma or supratentorial ganglioglioma during the study period, but was probably worthwhile in identifying recurrence of posterior fossa ependymoma and optic/hypothalamic astrocytoma and, possibly, medulloblastoma. Surveillance protocols could be made more effective by individualizing them for each type of tumor, based on current data on the patterns of recurrence.

Intrathecally administered baclofen for treatment of children with spasticity of cerebral origin.

Management of severe spasticity in children is often a difficult problem. Orally administered medications generally offer limited benefits. This study examines the value of intrathecally administered baclofen in the treatment of 19 children with severe spasticity of cerebral origin: eight of whom sustained brain injury associated with trauma, near drowning, or cardiac arrest; 10 with cerebral palsy (spastic quadriplegia); and one child with Leigh's disease. At the time of entry into the study, patients ranged from 4 to 19 years of age, and all were completely dependent on caretakers for activities of daily living. Children who responded positively to a trial dose of intrathecal baclofen underwent insertion of a drug delivery system for continuous infusion. This was followed by a double-blind trial of baclofen or placebo and follow-up review at 3 and 6 months, and yearly thereafter. Seven children did not undergo pump implantation because of excess sedation or poor response. The 12 remaining children have been followed for a period of 1 to 5 years. Favorable responses were present in all 12 children as determined by the Ashworth Scale, with the greatest benefit being reduction of lower limb tone. Except in the case of one child who had reduction in lower limb tone that resulted in difficulty with transfers, the caretakers all reported significant benefits from intrathecal baclofen, with improvement in muscle tone, behavior, sitting, and general ease of care being most commonly noted. Central side effects were seen in some children who received continuous intrathecal baclofen infusion and included hypotension (two patients), bradycardia (two), apnea or respiratory depression (two), and sedation (one). During a total of 568 months of pump operation there were 10 mechanical complications, including two related to pump or side port failure and eight related to catheter kinks, extrusions, or dislodgment. Pump pocket effusion occurred in five children and a cerebrospinal fluid fistula was seen in one child. Local infection occurred in three children and meningitis in two children. The results demonstrate the potential value of continuous intrathecal baclofen infusion for treatment of severe spasticity of cerebral origin. However, this treatment can result in significant complications and more experience is required before the long-term benefits can be determined.

Relationship of intraoperative electrophysiological criteria to outcome after selective functional posterior rhizotomy.

At British Columbia's Children's Hospital, the criteria used in selective functional posterior rhizotomy (SFPR) evolved in three distinct phases. In Phase 1 the electrophysiological criteria for abnormality included a low threshold to a single stimulation, a sustained response to 50-Hz stimulation, and spread outside the segmental level being stimulated. In Phase 2 the electrophysiological criteria were unchanged, but fewer L3-4 nerve roots were cut. In Phase 3, fewer L3-4 nerve roots were cut, as in Phase 2, but based on the results of posterior nerve root stimulation in nonspastic controls, the only electrophysiological criterion used was contralateral and suprasegmental spread. The present study examined the relationship between the criteria used in each phase and patient outcome. The records of 77 consecutive children who underwent SFPR and had a minimum follow-up period of 1 year were reviewed, comprising 25, 19, and 33 patients in Phases 1, 2, and 3, respectively. Outcome parameters included quantitative assessments of lower-limb spasticity and range of motion, and qualitative assessments of lower-limb function. In Phase 3, 52% of the nerve roots were cut, compared to 66% in Phases 1 and 2. In all three phases there was a significant decrease in lower-limb spasticity and an increase in range of movement, with the smallest decrease in spasticity in Phase 3. Over 90% of children in each phase improved with respect to lower-limb function, and excluding independent walkers and quadriplegics confined to a wheelchair, improvement in the level of ambulation occurred in 87.5%, 71.4%, and 73.7% of patients, in Phases 1, 2, and 3, respectively.

Surgical implications of cerebral dysgenesis.

Cerebral dysgenesis encompasses varied disorders of brain development. Based on the understanding of these conditions provided by histopathologists, embryologists, radiologists and developmental pediatricians, surgeons are able to appropriately assist in the care of these patients. The surgeon can offer assessment of the ventriculomegaly that commonly accompanies cerebral dysgenesis in addition to providing methods to control hydrocephalus, to reconstruct cranial and facial malformations and to remove dysfunctional tissue. For most patients, surgical intervention is only one of the many factors that determine developmental prognosis. Based on the foundation built by other specialists, this review discusses cerebral dysgenesis from the perspective of historical and current surgical interventions.

Intrauterine hydrocephalus and ventriculomegaly: associated anomalies and fetal outcome.

Advances in fetal diagnostic techniques have opened many areas to prenatal anatomical scrutiny. Intrauterine hydrocephalus and ventriculomegaly are conditions which are readily diagnosed. Fetal intervention has been undertaken in humans in order to minimize the craniofacial disfigurement and to maximize the growth potential of the brain. To justify such an approach, the significance of all anomalies should be recognized prior to treatment. The authors have reviewed 41 cases of hydrocephalus diagnosed in utero in order to define associated anomalies and patient outcome. 75% of our personal series and 72% of the reviewed literature cases had other anomalies of the central nervous system. Other system malformations, some of which proved fatal, were seen commonly. Prenatal diagnostic techniques did not always reveal these additional problems. The outcome of these pregnancies is not good. Approximately one third of these fetuses have survived to be treated postnatally and to be followed up clinically. Only 7.5% of this series were felt to have attained normal developmental milestones. The remainder of the survivors have various focal and/or global cerebral deficits.

Clinical - radiological correlates in intracerebral hematomas due to aneurysmal rupture.

In this series of intracerebral hematomas from aneurysmal rupture, gathered from several neurosurgical services, certain morphological features were studied in detail. Patients with very large hematomas tended to have poor neurological grades on admission to hospital and their immediate discharge outlook was correspondingly poor. Ruptured middle cerebral and pericallosal artery aneurysms were relatively common causes of intracerebral hematomas. Patients with temporal lobe hematoma did relatively well; those with parietal hematoma did poorly. The larger the hematoma the less chance there was of developing cerebral vasospasm but the more likely was pre-operative brain herniation. The survival was more closely linked to size and location of the hematoma than to the location of aneurysm or the degree of midline shift.

Intramedullary spinal cord tumors in children.

Intramedullary spinal cord tumors are uncommon in children, and delayed diagnosis is common. Unlike the situation in adults, low-grade astrocytomas predominate followed by ependymomas and other gliomas. Recent technological advances, including MR imaging, intraoperative ultrasonography, the ultrasonic surgical aspirator, and the operative laser, have made radical resection of intramedullary tumors feasible. The long-term results of modern-day surgery using these techniques are only now becoming available, and the role of adjuvant radiotherapy or chemotherapy for the usual low-grade tumors remains unclear. The risk of spinal deformity after laminectomy in children and the effects of radiotherapy on the growing spine create special challenges in the treatment of pediatric intramedullary tumors.

Ventricular shunting for hydrocephalus in children: patients, procedures, surgeons and institutions in English Canada, 1989-2001.

INTRODUCTION AND PURPOSE: Ventricular shunting remains the principle and most generally applicable method to treat hydrocephalus in children. This paper describes the demographics of this treatment in English Canada during the period of 1989 to March 2001. METHODS: Hospital discharge records were obtained for patients less than 18 years who had a shunt inserted or revised. A database was constructed relating patients and procedures to hospital discharges based on scrambled patient identifiers, year of birth, sex, postal code and diagnoses. OBSERVATIONS: 5,947 patients underwent ventricular shunting procedures for hydrocephalus in this period. 261 surgeons working in 73 institutions provided 12,106 interventions (Shunt insertions: ventriculoperitoneal--5009, ventriculoatrial--119, ventriculopleural--28. Revisions: 6,950). Infection was deemed to have occurred in 1,059 procedures. Over the study period, the median number of procedures performed per surgeon per year was 2, with 75 % of surgeons performing 5 or fewer procedures in children per year. Although many surgeons operated on children throughout the thirteen years of the study, many did not acquire substantive cumulative experience. Overall infection rate was 8.6 %. Surgeon infection rates were greater than or equal to 20 % during the first four years of practice and thereafter they fell to and remained in the 10 % range. The mean shunt survival at 12 months of individual surgeons varied between 50 - 60 %, regardless of the number of years of experience of the surgeon; however, performance variability as measured by the standard deviation of 12 month survival rates for all surgeons, adjusted for years of experience, ranged widely until the fifth year of practice. The average number of procedures per year for treating hospitals was 2 with 75 %, providing 12 or fewer services annually. Over the entire study, 50 % of institutions provided 10 or fewer procedures. The mean institutional infection rate was 11.4 % (SD 23, median--6.0). CONCLUSIONS: Quality monitoring of infection rate and duration of shunt function remains critical as many surgeons and hospitals provide care to children with hydrocephalus infrequently. Variability in infection rates and shunt survival at 12 months are a function of surgeon experience, measured by years in practice. Variability in outcome decreases with increasing surgeon experience.

Clinical outcomes that fetal surgery for myelomeningocele needs to achieve.

INTRODUCTION: The development of techniques to close open neural tube malformations prior to birth has generated great interest and hope for fetal interventions and their outcomes. To plan a randomized trial, as is being discussed at three centres in the United States, the determination of what constitutes a clinically significant improvement in outcome is critical. To date, preliminary observations from two centres suggest that improvements may occur, not in spinal cord function as originally postulated, but in the extent of the hindbrain hernia and the frequency that shunting is required to control hydrocephalus. PURPOSE: The determination of what outcome would constitute an important and clinically significant difference in outcome to be achieved by fetal intervention for myelomeningocele. METHOD: Parents of patients and patients treated in our myelomeningocele clinic were surveyed using a structured and validated tool. From the perspective of a recommendation to a close friend or family member, the interviewees were asked to quantify on a scale from 0 to 100 the chance of specific outcomes (need for a shunt, need for a wheelchair, change of urinary incontinence) that a fetal operation would need to predictably achieve. RESULTS: Responses were obtained from 77 patients/families. The fifty percentile response in each study dimension was as follows: the chance of needing a shunt was 12 % (range 0 - 50 %), the chance of needing a wheelchair was 8 % and the chance of being incontinent was 5 % (range 0 - 25 %). CONCLUSIONS: Fetal interventions will have to achieve significant improvements in the control of hydrocephalus, mobilization and continence over postnatal treatment to be justified.