Paul Steinbok

Long-Term Follow-Up Data from the Shunt Design Trial

Background: A previously reported multicenter randomized trial assessed whether 2 new shunt valve designs would reduce shunt failure rates compared to differential pressure valves. The study did not show a significant difference in the time to first shunt failure. Patients entered the trial between October 1, 1993, and October 31, 1995. The primary results were based on the patients’ status as of October 31, 1996 (a minimum follow-up of 1 year). This report describes the late complications based on the patients’ most recent follow-up. Methods: Three hundred and forty-four hydrocephalic children at 12 North American and European centers were randomized to 1 of 3 valves: a standard differential pressure valve; a Delta valve (PS Medical-Medtronic) or a Sigma valve (NMT Cordis). Patients were followed until their first shunt failure. Shunt failure was defined as shunt surgery for obstruction, overdrainage, loculation or infection. If the shunt did not fail, follow-up was continued until August 31, 1999. Results: One hundred and seventy-seven patients had shunt failure. Shunt obstruction occurred in 131, overdrainage in 13, loculated ventricles in 2 and infection in 29. The overall shunt survival was 62% at 1 year, 52% at 2 years, 46% at 3 years, 41% at 4 years. The survival curves for the 3 valves were similar to those from the original trial and did not show a survival advantage for any particular valve. Conclusions: Prolonged follow-up to date does not alter the primary conclusions of the trial: there does not appear to be one valve that is clearly the best for the initial treatment of pediatric hydrocephalus.

A randomized clinical trial to compare selective posterior rhizotomy plus physiotherapy with physiotherapy alone in children with spastic diplegic cerebral palsy.

A randomized controlled single‐blind trial was performed to compare lumbo‐sacral selective posterior rhizotomy (SPR) followed by intensive physiotherapy, with intensive physiotherapy alone in improving motor function in children with spastic diplegic cerebral palsy. Fifteen patients were randomly assigned to each treatment modality. Patients in the SPR group had rhizotomy within 1 month, followed by intensive outpatient physiotherapy for 9 months. Patients assigned to physiotherapy alone had identical intensive physiotherapy. There was a statistically significant and clinically important difference in improvement in motor function in favor of the SPR group, with a mean increase in total Gross Motor Function Measure (OMFM) score of 11.3% at 9 months for the SPR group compared with 5.2% for the physiotherapy‐only group (P=0.007). Significant improvements in spasticity (P<0.001) and range of movement (P<0.001) were noted in the SPR group compared to the physiotherapy‐only group. The results indicate that the improvement in motor function after SPR is more than can be explained by the associated intensive physiotherapy.

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.

Long-term outcome and complications of children born with meningomyelocele

The long-term functional outcome of 101 children born with meningomyelocele between 1971 and 1981 was assessed, by a combination of retrospective chart review and follow-up assessments. The children had been managed at birth using a process ofnonstandardized selection. Eighty-three of the 101 patients survived after a minimum follow-up of 8.6 years, for a mortality rate of 18%. Forty-four of 83 children (53%) were community ambulators, and this correlated well with the presence of intact quadriceps function. Forty-eight children (58%) attended normal school and were grade-appropriate. Sixty-two of 83 patients (75%) were socially continent of urine, and 71/83 (86%) were socially continent of stool. Hydrocephalus was present in 93 of the 101 children in the study, and 85 children were shunted. Half of the shunted children required a shunt revision in the first year of life, and thereafter the rate of revision decreased, so that after 2 years the risk of revision was approximately 10% per year.

International survey on the management of Chiari I malformation and syringomyelia

IntroductionThe availability of magnetic resonance imaging (MRI) has resulted in an increasing number of asymptomatic, minimally symptomatic, and doubtfully symptomatic patients being diagnosed with a Chiari I malformation with or without syringomyelia. In an attempt to clarify how neurosurgeons manage these clinical problems, an international survey on the Chiari I malformation and related syringomyelia was undertaken.MethodA questionnaire on the expected natural course of the disease and on aspects of the surgical technique for a number of hypothetical cases relating to Chiari I malformation with and without syringomyelia was used to survey Pediatric Neurosurgeons worldwide.ResultsOf 246 questionnaires distributed, 76 (30.8%) were completed and returned. There was a consensus that no operation should be carried out in asymptomatic patients with a Chiari I malformation, unless there is associated syringomyelia. There was a consensus that decompression of the Chiari malformation should be performed in patients with scoliosis when syringomyelia is present, and the majority decompressed the Chiari malformation in scoliotic patients even in the absence of syringomyelia. Suboccipital decompression was the standard surgical procedure for Chiari I malformations. The majority of respondents favored routine dural opening at surgery and closure with a pericranial or synthetic patch graft. In the case of a persistent or progressive syrinx after suboccipital decompression, the majority recommended shunting of the syrinx to the subarachnoid space or to the pleural cavity.ConclusionThere continues to be much variation in the management of the Chiari I malformation.

Hemispheric Surgery in Children with Refractory Epilepsy: Seizure Outcome, Complications, and Adaptive Function

Summary:  Purpose: To describe seizure control, complications, adaptive function and language skills following hemispheric surgery for epilepsy.

The Surgical and Natural Morbidity of Aggressive Resection for Posterior Fossa Tumors in Childhood

The morbidity associated with gross total removal of pediatric posterior fossa tumors is well recognized although it is rarely isolated from other factors that comprise the management morbidity for these tumors. This study reviews (1) the operative and postoperative complications in 105 patients and (2) the neurological morbidity in a subset of 91 patients undergoing gross total removal of their tumor between 1982 and 1992. Gross total removal was achieved in 102 patients with a single procedure. Two patients with residual tumor underwent early repeat craniotomy for excision and 1 is being followed without repeat resection. Intra- and postoperative complications occurred in 33 patients and included hematoma requiring craniotomy (3), gastrointestinal hemorrhage (2), hydrocephalus requiring shunt placement (9), wound problems (4), and pseudomeningocele formation requiring additional treatment (5). Delayed onset hydrocephalus requiring shunting occurred in 2 patients and spinal deformity in 4 patients. Worsening of preoperative deficit (new cranial nerve palsies, worsening ataxia, bulbar dysfunction including apnea, mutism and seizures) occurred in 41% of patients operated on for primitive neuroectodermal tumors (PNET) (14/34), 53% of ependymomas (10/19), and 30% of astrocytomas (15/50). No patient who had a choroid plexus tumor was worsened by the procedure. Complete recovery of new postoperative deficits occurred in 14% of PNET (2/14), 50% of ependymoma (5/10) and 47% of astrocytoma (7/15), most often within 6 months of the procedure. Residual neurological morbidity, due to persistence of preoperative symptoms or due to deficits that occurred as the result of the surgical procedure, was assessed in a subgroup of 91 patients followed for an average of 48 months (2-147 months). This assessment did not include morbidity due to adjuvant therapy. Sixty-two percent of patients continued to exhibit abnormal cerebellar or bulbar signs. Forty-three percent of the total population exhibited limitation in function due to residual deficit. Only 38% of patients were both functionally normal and had a normal neurological examination at last follow-up.

Outcomes after selective dorsal rhizotomy for spastic cerebral palsy

Abstract Object: The purpose of this article was to review the published outcomes after selective dorsal rhizotomy (SDR) for treatment of spastic cerebral palsy. Methods: A literature search identified all articles related to outcomes after SDR. The outcomes were reviewed according to a paradigm developed by the National Center for Medical Rehabilitation Research (NCMRR). The quality of the evidence for each outcome was assessed using Sackett’s criteria and the classification system developed by the Brain Trauma Foundation and the American Association of Neurological Surgeons. Results: There is very strong evidence for benefits of SDR in the impairment domain of the NCMRR classification. SDR has been shown conclusively to decrease lower limb spasticity and increase lower limb range of motion. There is strong, but not as conclusive evidence that SDR has a positive impact in the functional limitation dimension, with improvements in motor function, and in particular the Gross Motor Function Assessment (GMFM). There is a moderate degree of certainty that SDR results in improvements in the disability dimension, as evidenced particularly by improvements in the Functional Independence Measure for Children (WeeFIM) and Pediatric Evaluation of Disability Inventory (PEDI). There is a moderate degree of certainty that SDR results in positive suprasegmental effects, especially related to upper limb function and cognition. There is weak evidence that SDR may reduce the need for orthopedic procedures in patients with spastic cerebral palsy, and the impact on hip subluxation relative to the natural history of this problem is unclear. Conclusions: This information could help to define the role of SDR in the management of the child with spastic cerebral palsy, in the light of alternative therapies, such as intrathecal baclofen and botulinum toxin, which have been introduced more recently. It also reveals the need for further studies, particularly dealing with quality of life and economic impact.

The value of routine cultures of the cerebrospinal fluid in patients with external ventricular drains.

OBJECTIVE The purpose of this study was to determine whether routine cerebrospinal fluid (CSF) bacteriological cultures in patients with external ventricular drains (EVDs) can identify infections early and prevent complications related to bacterial ventriculitis. METHODS We retrospectively reviewed the microbiological reports and clinical data for all patients in whom an EVD was placed at a tertiary care pediatric neurosurgical center between 1984 and 1997. EVDs were inserted in the operating room or intensive care unit, and, in most patients whose EVD remained in place for more than 2 days, daily cultures of CSF were performed. RESULTS One hundred fifty-seven patients in whom 160 EVDs had been placed were included in the study. Forty-eight positive cultures were identified, of which the majority were determined to be contaminants. Seven infections were identified on the basis of microbiological criteria (i.e., a gram-positive stain and positive culture) and a subsequent positive culture. In all patients in whom infections developed, routine daily cultures of CSF were performed, and, in each instance, these cultures failed to identify the infections before clinical changes occurred. All seven patients with infection had fever (>38.5 degrees C) and peripheral leukocytosis (>11 x 10(3)/mm3) on the day the infection was identified, and one had a change in CSF appearance. CONCLUSION The results of this study suggest that routine culture of CSF in children with EVDs is not necessary, and that if CSF cultures are performed for new fever (>38.5 degrees C) or peripheral leukocytosis, neurological deterioration, or a change in CSF appearance, infections will be identified in a timely fashion. In situations in which these clinical indicators might be masked, routine cultures may be valuable.

Complications after Selective Posterior Rhizotomy for Spasticity in Children with Cerebral Palsy

Selective dorsal rhizotomy (SDR) has been shown to be an effective treatment for the spasticity of cerebral palsy, but few studies have addressed specifically the side effects of the procedure. A retrospective study was performed to determine the frequency and nature of complications in 158 children who had undergone SDR at British Columbia’s Children’s Hospital from 1987 to 1996. Intraoperative, preoperative (immediate postoperative until discharge at approximately 7 days) and postdischarge complications occurred in 3.8, 43.6 and 30% of patients, respectively. The most common intraoperative complication was aspiration pneumonia, which was experienced by 2 patients (1.3%). Perioperatively, sensory changes were found in 8.9% of the children, and transient urinary retention in 4.4%. Complications after discharge included back pain starting more than 6 months after surgery in 10.8%, sensory changes in 13.9%, and neurogenic bladder or bowel problems in 12.7%. Persistent sensory changes occurred in 3.8%, were not important functionally, and tended to occur in patients with the largest amount of dorsal root tissue cut. In 8 patients (5.1%), bladder and/or bowel dysfunction attributed to the SDR was present at the latest follow-up, although in only 2 patients (1.3%) this dysfunction was a definite complication of the rhizotomy. The use of pudendal monitoring and/or cutting less than 50% of the S2 roots may have been associated with a lower incidence of long-term sphincter dysfunction. Data about the nature and frequency of complications may result in further modifications to the SDR procedure, and is critical for counseling about SDR and alternative options available for treatment of the child with spastic cerebral palsy.