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The relationship of surgeon experience, measured by operative volume, to the outcomes of ventricular shunt treatment of hydrocephalus in children is not clear. This paper explores this relationship based on first ventriculoperitoneal shunts (VPS) implanted in English-speaking Canada during the period from April 1989 to March 2001. Three thousand seven hundred and ninety-four first VPS insertions, performed by 254 surgeons, were reviewed. Surgical experience was represented by the number of shunt operations performed during the study period by each surgeon prior to the date of the operation. The 6-month shunt failure risk for less experienced surgeons was 38%, compared to 31% for more experienced surgeons. This difference decreased to 4% at 60 months and 3% at 120 months (p = 0.001). The infection rate for initial shunt insertions was 7% for patients treated by more experienced surgeons and 9.4% for those treated by less experienced surgeons (p = 0.006). A relationship between surgeon experience and shunt outcome that appears to be based on the operative experience that a surgeon brings to a procedure is in keeping with clinical experience. This observation has implications for public policy, service planning and surgical mentorship during the earlier years of a surgeon’s career.Copyright © 2003 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Little is known about the long-term prognosis of patients with cervical myelocystoceles and meningoceles. In this study, we report the long-term follow-up (average 10 years and 8 months) of 8 patients with cervical myelocystoceles and meningoceles. Neurologic, orthopedic, urologic and psychosocial status was assessed on long-term follow-up. The results indicate that in patients with cervical myelocystoceles, neurologic deficits become noticeable in the first year of life as the infant matures. Motor deficit was common in these patients, whereas sensory and urologic deficits did not occur. We believe that this is related to underlying myelodysplasia. In addition, patients with cervical myelocystoceles tend to have significant orthopedic problems. In contrast, patients with cervical meningoceles do not have neurologic deficits, but do develop mild orthopedic problems., (Copyright 2000 S. Karger AG, Basel)

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.

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.

Placode untethering in myelomeningocele patients can result in improvement and/or stabilization of neurological function, spinal curvature and pain. This paper reviews the outcome of untethering procedures in 24 patients to determine the frequency of subsequent functional deterioration. Decreased range of movement, joint stiffness and changes in muscle tone were the commonest indications for surgical intervention, occurring in 15 patients. Untethering resulted in improvement in 8 patients, stabilization of progression in 6 and continued deterioration in 1 patient. Two patients previously untroubled with spasticity became symptomatic within 3 months of the procedure. Changes in ambulation were present preoperatively in 9 patients. Stabilization was observed in 4 and improvement in 5. One of the patients, who had improved, deteriorated during the 1st year of follow-up. Alterations in bladder capacity and continence occurred in 7 patients. Improvement was seen in 2 patients, deterioration in 2 and no change in 3. Of the patients who improved, 1 subsequently deteriorated again within the 2nd postoperative year. Of those patients who had stable bladder function preoperatively, 6 subsequently deteriorated despite untethering. Pain was a less frequent symptom, occurring in 6 patients. Six patients became pain-free within 3 months of untethering. Two patients who did not have pain preoperatively had pain at the operative site persisting for up to 3 months postoperatively. Of the 20 patients having a single untethering procedure to date, 11 have further symptoms that can be attributed to retethering.

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.

Objective: Prenatal ultrasonography can localize the level of the spinal cord malformation, allowing prediction of the potential postnatal neurological deficit and functional prognosis., Methods: This study has two evaluations: (a) a retrospective prenatal review of 26 fetuses with spinal dysraphism (1987-1991), and (b) a follow-up descriptive study of patients (1971-1981) who underwent closure of the spinal lesion and ventricular shunting in the neonatal period., Results: Prenatal ultrasound evaluation enabled the accurate definition of the last intact vertebral level which allows separation of fetuses into three functional groups (last intact level L2, L3-4, L5-sacral). Patterns of ambulation, urinary and bowel continence, and school performance vary according to level of spinal lesion and the neurological deficit. The need for ventricular shunts, the incidence of other spinal malformations and surgical interventions did not vary with the level of the spinal lesion., Conclusions: The functional outcome for patients with myelomeningocele is variable; however, distinct patterns emerge based on the level of spinal dysraphism and the resultant neurological deficit. By relating the level of the fetal spinal lesion to outcome data, more precise functional prognoses can be given to families.

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.

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.

Since 1969, the Meningomyelocele Clinic at British Columbia's Children's Hospital has been serving the needs of children with spina bifida. In 1994, the clinic provided urgent and routine multidisciplinary clinical assessments to 330 patients and families. The purpose of this study was to assess, from the patients' and families' perspective, the appropriateness of the frequency of routine clinic visits and the value of the health services provided. Sixty-five patients/families were interviewed and completed a questionnaire developed by the clinic. Current visit frequency and services provided appear to meet the patient/family needs. The medical and nursing contributions were seen as valuable resources for the patient/families resulting in most patient/families feeling well informed about spina bifida.

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.

The requirements for radiographic imaging of the ventricles after a ventricular shunt procedure are not well defined. At British Columbia's Children's Hospital, the standard protocol included an ultrasound examination or CT scan at 6-8 weeks postoperatively, and a delayed CT scan at 6 months to 2 years, with additional scans only if the patient had symptoms of shunt malfunction. This study was performed to determine if the delayed scan could be omitted without compromising patient care. The study comprised 86 children with ventriculoperitoneal shunt operations, who had early CT scans or ultrasound examinations less than 20 weeks postoperatively, delayed postoperative CT scans between 20 weeks and 2 years, and who were asymptomatic at the time of these radiographic studies. In 39 of the 86 patients a change in ventricular size occurred between the early and delayed imaging studies, and in these patients the delayed scan was felt to be required. In patients in whom the early imaging study was done at more than 12 weeks postoperatively, and probably in patients with small ventricles preoperatively, there was no added information gained by doing a delayed scan. It is concluded that a radiographic examination of ventricular size at 12 weeks after a shunt operation may provide an adequate baseline study. If the early postoperative radiographic study is done less than 12 weeks after surgery, we would advise that in asymptomatic patients, with the exception of patients with very small ventricles preoperatively, a CT scan be repeated at a later date to obtain an appropriate baseline assessment of ventricular size for the future.

Acute subdural hematomas in the full-term neonate are usually thought to be a manifestation of birth trauma. Most commonly, these hematomas are associated with a tentorial tear, and less frequently are secondary to damage to the occipital sinus accompanying occipital osteodiastasis, or to rupture of bridging superficial cerebral convexity veins. We report 6 cases of acute subdural hematoma associated with cerebral infarction (SDH/CI) in term neonates, an entity which has not been well-documented previously. This combination accounted for half the cases of neonatal acute subdural hematomas referred to a pediatric neurosurgical service. All children presented within 72 h of birth, usually after an uneventful delivery, and typically with seizures (5/6), apneic spells (3/6) and a full or bulging fontanel (5/6). Although the patients were referred to the neurosurgical servive for management of a convexity subdural hematoma, the CT scans showed a large associated cerebral infarct, which was hemorrhagic in 5 of the 6 cases, most commonly in the distribution of the middle cerebral artery. Craniotomy was performed in 4 patients, needle aspiration of the subdural hematoma in 1, and no surgical intervention in 1. The outcome in 3 patients, who have been followed for more than 1 year, has been good, with some mild focal neurologic deficits, but no seizure activity. The pathogenesis of this entity is unclear, but the acute subdural hematoma in these cases is probably secondary to the cerebral infarction. Recognition of SDH/CI as a specific entity in term neonates has significant management and possibly medicolegal implications.

The classification and embryogenesis of cystic cervical dysraphic lesions are discussed in the light of the authors' experience and review of the literature. It is felt that these lesions are best described as meningoceles or myelocystoceles, and the use of the term 'myelomeningocele' may be more confusing than clarifying. The authors hypothesize that the cervical meningocele and the myelocystocele are part of a spectrum of the same underlying developmental abnormality, namely limited dorsal myeloschisis, with the eventual abnormality depending on the presence or absence of associated hydromyelia.

The use of a ventriculosubgaleal shunt for temporary treatment of hydrocephalus in a child with multiple recurrent shunt infections related to eczema in the neck is described. Further shunt infection was avoided, the eczema cleared, and a permanent ventriculoperitoneal shunt was inserted successfully after 2 months.

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.

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.

Ventricular asymmetry is common after ventricular shunting, and occasionally isolation of the contralateral ventricle necessitates a second shunt. The following study was performed to determine whether contralateral placement of the ventricular catheter via ultrasound-guided perforation of the septum pellucidum would decrease the incidence of postshunting ventricular asymmetry which might predispose to symptomatic isolation of a lateral ventricle. Fifty-eight children with hydrocephalus and an open fontanel, who were having a ventriculo-peritoneal shunt via a parieto-occipital approach, were randomized to have the ventricular catheter tip placed into either the ipsilateral or the contralateral frontal horn. Ventricular asymmetry occurred in 23% of the patients with contralateral versus 54% with ipsilateral placement (chi 2 = 5.53; p = 0.019). In 7 patients with contralateral placement, in whom a special catheter with two sets of holes was used, such that holes were located in both ventricles, no shunt-related ventricular asymmetry occurred. In 2 children with ipsilateral placement, a second shunt was required for a symptomatic isolated lateral ventricle. Perforation of the septum pellucidum with placement of the ventricular catheter in the contralateral ventricle, using a specially designed catheter with two sets of holes, may decrease the incidence of postshunting ventricular asymmetry and symptomatic isolation of a lateral ventricle.

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.

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.

Selective functional posterior rhizotomy (SFPR) is a popular operation for the treatment of spasticity in children with cerebral palsy, but the physiologic basis of the procedure is poorly understood. As part of SFPR operations in 60 consecutive children, the responses to electrical stimulation of posterior lumbosacral roots and rootlets, and the corresponding anterior roots were studied. In addition, similar electrical stimulation of posterior roots was performed in four nonspastic "control" children. Sustained responses to 50 Hz stimulation, one of the criteria used to signify abnormality in the spastic children, was found frequently in the "control" children. Contralateral spread to the lower limb muscles and suprasegmental spread to the upper limbs, face, and neck were determined to be the most valid criteria which differentiated abnormal from normal responses. Stimulation of anterior nerve roots at 50 Hz caused sustained responses and ipsilateral lower limb spread, at a low threshold compared to that of corresponding posterior roots. The results of this study bring into question the validity of some of the criteria that are used to select abnormal posterior rootlets in the SFPR procedure, and suggest criteria that may be more valid based on findings in nonspastic children.

In order to restore spinal integrity following posterior exposures of the spinal canal in children, we describe modifications of Raimondi's laminotomy technique. The use of a pneumatic dissecting tool with foot-plate to create a hinged osteoplastic laminotomy is described, as are techniques for securing the laminotomy flap in place at the end of the procedure.

Surgical educators are facing changes in residency training that have a direct impact on the opportunity that surgeons and residents have for clinical teaching and learning. The knowledge required of residents continues to escalate. Further, as resident positions are reduced, the opportunity for inter-resident education is decreased. Increased service-to-education ratios may result in resident discontent unless surgeons take an active role in the resident's educational experience. The purpose of this study was to examine the educational activities that occur during the operating-room experience. Technical training in the procedure being done was the primary educational activity, but there were long periods when no form of education was taking place. The operating room provides the teacher and learner with uninterrupted time together, and this time can and should be used for clinical teaching and learning.

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 of nonstandardized 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.

Fifty consecutive children are described with spastic cerebral palsy treated with selective functional lumbar and sacral rhizotomy and followed for a minimum of 6 months. In all patients, spasticity improved postoperatively, but this was not necessarily accompanied by a functional improvement. Eighteen children who could not walk preoperatively were able to do so after rhizotomy. All 17 children who could walk preoperatively could do so following surgery, and in 15, gait was improved. Complications included transient urinary dysfunction in 4 children and sensory loss in 1. The operative procedure evolved with time: the technique of replacement laminotomy was refined; the electrophysiologic basis for selection of nerve rootlets changed after studies of nonspastic controls; smaller percentages of the L3 and L4 roots were sectioned in an attempt to prevent postoperative weakness of quadriceps, and there was a trend in the most recent patients to cut a smaller portion of all the posterior roots.

The technique for freeing adherent ventricular catheters is described in which a Bugbee wire, insulated except for the tip, is used to deliver a monopolar coagulating current to the tissue adherent to the drainage holes of the catheter. This may have some advantage over the use of an uninsulated metal cannula for delivery of a unipolar diathermy cutting current. The technique described has permitted effective and safe removal of adherent ventricular catheters.