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An association between terminal syringomyelia (TS) and tethered cord syndrome (TCS) has been recognized. The clinical significance of TS and the need for concurrent treatment is not known. Thirty-four patients with TCS undergoing surgery for tethered cord release were evaluated for the incidence of TS. The clinical and radiological response to untethering with and without syrinx drainage was assessed. The group incidence of TS was 29.4%. There were no significant differences in the sex, age, underlying pathology or preoperative symptoms between the TCS group (TCS, n = 24) and the TCS group with TS (TCS + TS, n = 10). In the TCS group, 37.5% of the patients were asymptomatic preoperatively, and in the TCS + TS group 50% were asymptomatic preoperatively. After surgery, none of these asymptomatic patients developed symptoms. All of the symptomatic TCS + TS patients improved clinically, 12 of 15 symptomatic TCS patients improved, 2 patients were unchanged and 1 had worsening scoliosis. Syrinx did not develop in patients lacking it preoperatively. In patients where postoperative imaging was available, preoperative syringes improved. TS is clearly associated with TCS. Tethered cord release alone may be sufficient to improve preoperative symptoms and TS may be an associated phenomenon that does not mandate separate treatment.

Objective: Ventriculoperitoneal shunts have one of the highest complication rates of all neurosurgical procedures. The purpose of this study was to identify factors associated with malfunction of shunts placed in infants with neonatal hydrocephalus, with the goal of maximizing long-term shunt survival., Methods: We performed a retrospective chart review of 200 consecutive patients less than 1 year old who underwent primary intracranial shunt placement for hydrocephalus by one of two experienced pediatric neurosurgeons at a single institution. A multivariate analysis was conducted to identify variables that were statistically independent predictors of a shunt malfunction or problem., Results: Adequate data were available for 158 patients, with a mean follow-up of 39.8 months (range 6-99 months). Variables tested for independent prediction of shunt revision included the etiology of the hydrocephalus, gestation period, age at shunt placement, surgeon, ventricular catheter entry site and valve opening pressure. Frontal versus occipital catheter entry site was not associated with a different revision rate. The only significant controllable factor associated with shunt malfunction was the valve opening pressure. The revision rate per year of follow-up was 4 times higher for patients with no valve or a low-pressure valve than for patients with a medium- or high-pressure valve., Conclusions: This retrospective review demonstrated that the valve opening pressure is an important component of the shunt complication rate. A prospective multicenter randomized trial is warranted to further evaluate the conclusions of this study., (Copyright 2002 S. Karger AG, Basel)

In 2 cases of infants with the Chiari II malformation, a prepontine cyst presented in association with the hindbrain abnormalities characteristic of the Chiari II syndrome. Both infants presented with bulbar dysfunction and had poor outcome despite decompression of the cerebellar tonsillar herniation and drainage of the prepontine cysts. No such association between prepontine lesions and Chiari II has been described previously., (Copyright 2000 S. Karger AG, Basel)

A functioning shunt must have a patent proximal catheter within the cerebrospinal fluid space. Occlusion with choroid plexus or ependymal tissue might be expected if these tissues are in contact with the proximal inlets. This study was undertaken to define the intraventricular distances available for a standard-placement shunt cather and to compare the available distances with actual ventricular catheter inlets. In 52 normal subjects (age range from 1 month to 20 years; median 7.7 years) magnetic resonance imaging was used to measure the dimensions of the anterior horn in planes typically used for cather placement. For anterior placements, the intraventricular length (ventricle entry to the foramen of Monro) was measured for a standardized catheter route ('As') and for a route yielding a maximum lenght ('Amax'). For posterior placements, the length (ventricle tip to foramen of Monro) was obtained for a standardized catheter placement to the ipsilateral ('Pi') and the contralateral ventricle ('Pc') as well as measuring a maximum length in a curved trajectory ('Pmax'). The average length (and range) in centimeters for the various trajectories was: As = 1.5 (1.1-1.9), Amax = 1.7 (1.2-2.2), Pi = 1.6 (1.2-2.1), Pc = 2.0 (1.4-2.9), and Pmax = 2.8/3.1 (2.1-3.6). Minor variations from a standard shunt insertion site did not affect the length of catheter within the ventricle. Current ventricular catheters have proximal inlets extending 1.6-2.4 cm from the catheter tip. Variations in standard ventricular catheter placement should have no measurable effect on how much ventricle is available for the proximal catheter. It may not be possible to place a standard ventricular catheter and keep the inlets within the ventricle and placed consistently away from choroid plexus and ependyma, regardless of approach. This may contribute to the similar proximal occlusion rates reported for the differing placements. Subsequent studies of shunt placement should correlate proximal occlusion rates with ventricular size. To prevent ventricular size from directly affecting proximal conclusion, consideration should be given to altering the design of ventricular catheters by placing inlets over a shorter distance (1.0 cm) from the tip.

Objective: This study was undertaken to determine the necessity for routine hospital admission of children with skull fractures, a normal neurological exam, a normal head CT, and no other injuries ('uncomplicated skull fracture')., Methods: A prospective study of closed-head injuries in children was done over a 2-year period at St. Louis Children's Hospital. All patients with closed head injuries underwent skull radiographs and a head CT scan. From this cohort, children with uncomplicated skull fractures were identified and studied. For comparison, a retrospective analysis was also performed of the hospital admission records of children admitted over a 5-year period (1990-1994) with the diagnosis of epidural hematoma (EDH) to identify the typical time intervals between injury and documentation of the lesion in these cases., Results: Forty-four patients with uncomplicated skull fractures were identified; all had been admitted for observation. Mean age was 1.8 years. Average time between injury and hospital admission was 6.35 h with half of this time being spent in the emergency room. Average LOS was 35 h, but 50% of patients were hospitalized less than 24 h. No patient in this study group suffered a complication related to their inury. Twenty-three patients with EDH had been admitted during the 5-year review period. Slightly more than one-half of patients had their EDH detected within 6 h of injury. The others were diagnosed more than 6 h after injury due to a delay in medical evaluation or a delay in obtaining a computed tomographic (CT) scan after an initial medical evaluation., Conclusions: Patients with uncomplicated skull fractures, in the absence of recurrent emesis and/or evidence of child abuse, can be considered for discharge home. The definition of an uncomplicated skull fracture requires that a head CT be performed on these patients.

The hallmarks of tethered cord syndrome are a low-lying conus medullaris and a thick filum terminale. In diagnosing the tethered cord syndrome, the thick filum terminale is often defined as that greater than 2 mm in diameter. The cutoff of 2 mm in diameter was derived from myelographic measurements a few decades ago, and the true normal diameter of the filum terminale diameter in children or adults remains unknown. We measured the diameters of the filum terminale in vivo in the operating room on 31 children (age range = 2-14 years; mean age = 5 years) undergoing selective dorsal rhizotomy for spastic cerebral palsy. None of them had clinical evidence of tethered cord syndrome. The conus medullaris and filum terminale were videotaped intraoperatively and images were transferred to an image analyzer; the filum diameters at 10 and 15 mm caudal to the conus medullaris were then measured extraoperatively using the computer graphics system. The diameter of the filum at 10 and 15 mm caudal to the conus was 1,211 +/- 209 and 1,163 +/- 245 microm (mean +/- SD), respectively. In all children except one, the conus medullaris ended above the L2 level. The data indicate that filum terminales greater than 2 mm in diameter in children are abnormally thick.

Birth-related brachial plexus injury occurs in 0.19-2.5 per 1,000 live births, of which 70-92% improve with conservative management. With the advent of microsurgical techniques, patients who fail expectant treatment may benefit from brachial plexus exploration and reconstruction. From 1991 to 1996, 87 patients were referred to the multidisciplinary brachial plexus clinic at St. Louis Children's Hospital. Twenty patients were selected for surgical management. The average age at surgery was 10.5 months (range 3-35, median = 8), with an average follow-up of 23.9 months (range 7-45, median = 24). Two patients were lost to follow-up. Surgical procedures included neurolysis (n = 8), neurotization (n = 2), nerve grafting (n = 5), and a combination (n = 3) of the above. Two patients underwent exploration without repair. Intercostal nerves, pectoral nerves, and C4 roots were used for neurotizations, and the sural nerve was used for nerve grafting. Results from 18 patients were available for follow-up review. Fifteen patients (83% demonstrated clinical improvement postoperatively. Of the 3 patients without improvement, 2 underwent exploration without repair, and one underwent neurolysis of the axillary nerve. Of patients undergoing reconstruction, 93% had improved strength postoperatively. No subjects had worsening neurologic status, and there were no complications. These results suggest that surgery for birth-related brachial plexus injury may show favorable outcomes if patients are selected appropriately. Patients undergoing neurolysis and nerve grafting had more favorable outcomes than those undergoing neurotization.

Some children with Chiari malformation and achondroplasia require posterior fossa decompression that typically includes expansion of the dural tube with duraplasty. Infants and young children, however, may have a more distensible dura mater than do older patients. Furthermore, the structures that compress the hindbrain of young patients may be the bone and abnormally thickened atlantooccipital membrane, i.e., dural band, rather than the dura mater. We have treated 7 children who had Chiari malformation or achondroplasia with posterior fossa decompression without duraplasty. All children were symptomatic; 3 had Chiari-I malformations, 2 Chiari-II malformations, and 2 achondroplasia. The age range was 3 months to 2.5 years (mean 15.1 months). The exent of tonsillar herniation and other hindbrain anomalies was assessed on preoperative magnetic resonance imaging. The infants with Chiari-II malformations underwent cervical laminectomies, whereas the other young children with Chiari-I malformations or achondroplasia underwent suboccipital craniectomy as well as cervical laminectomy. In Chiari malformation, the dural band was divided; in achondroplasia, there was no identifiable dural band. Following bony decompression and division of the identifiable dural band, immediate expansion of the stenotic region with visible cerebrospinal fluid space posterior to the neural elements could be ascertained by intraoperative ultrasonography. During a follow-up period ranging from 4.5 months to 4 years (mean 22 months), all patients made improvements in their symptoms, 3 having complete resolution of their symptoms. This preliminary experience indicates that in children 2 years of age or younger, posterior fossa bony decompression without duraplasty can be effective treatment for Chiari malformations or achondroplasia.

A case is presented illustrating the usefulness of computerized tomography (CT) with 3-dimensional (3-D) reconstruction for evaluation of a subdental synchondrosis fracture in a child. Odontoid fractures in children less than 7 years of age occur at the subdental synchondrosis and are typically diagnosed with plain x-rays. However, a delay in diagnosis is common as these injuries may not be appreciated on initial roentgenographic evaluation. The authors present a case of a 2-year-old boy with a subdental synchondrosis fracture secondary to trauma. In this patient, plain x-ray and conventional axial CT failed to definitively elucidate the child's injuries; however, the use of CT with 3-D reconstruction fully delineated the injury. The use of CT with 3-D reconstruction in evaluating children with subdental synchondrosis fractures is a valuable tool for diagnosis. The treatment of synchondrosis fractures of the odontoid process in children is immobilization of the cervical spine.

Computed tomographic (CT) brain scans were performed without and with contrast enhancement within 24 h of craniotomy in 26 patients undergoing 27 operations. Postoperative scans were retrospectively reviewed for evidence of contrast enhancement, the pattern of enhancement and the presence of blood on the postoperative scans. Contrast enhancement was seen in the resection bed in 33% of patients undergoing gross total resection of their lesions, and was absent in 50% of patients with known residual disease. Enhancement along a corticotomy was present in 18% and distant meningeal enhancement was identified in 19% of patients. These enhancement rates were unrelated to steroid dosages, duration of surgery, or the interval between operation and scanning. It was not possible to delineate residual tumor in 63% of the patients, due to a postoperative enhancement pattern that stimulated enhancing vessels, the presence of hemorrhage, or due to the absence of calcification or preoperative enhancement. None of the scans were affected by technical problems (motion artifact, inability to complete the scan) potentially associated with scanning within 24 h of craniotomy. Small amounts of residual tumor remain undetectable, particularly due to hemorrhage in the resection bed. Although no distinct advantage in defining residual disease was obtained compared to scanning at 72 h, the overall rate of findings not related to neoplasm was slightly less for scans obtained within 24 h.

Clinical, radiological, and pathologic features of an intracranial chondroid chordoma in a 9-year-old boy are described. This is the first reported case of a chordoma, the center of which was laterally situated in the cranial base, lying in or near jugular foramen and carotid canal, but without midline involvement. Although cranial chordomas in childhood are extremely rare, and all previously reported cases appeared to have arisen in the clivus, this location should not be considered ectopic. Forking at the rostral end of the notochord has been demonstrated in embryos, and would be the presumed embryological source for this tumor. This is also the first reported case of a chondroid chordoma in a child with immunohistochemical documentation distinguishing it from a chondrosarcoma. This chondroid chordoma contained two populations of cells: neoplastic cartilage and chordoid tissue in a myxoid stroma. The distinction between chordoma and chondrosarcoma and the implications on treatment will be discussed.

Although magnetic resonance imaging (MRI) may be more sensitive than myelography with CT scanning in detecting spinal metastatic disease (SMD), the limitations of these MRI examinations have not been defined. The feasibility of obtaining early postoperative MRI to screen for SMD, and the type and frequency of imaging abnormalities were evaluated in this prospective study. Twenty-seven patients (78% with nondisseminating neoplasms or nonneoplastic diseases) were studied with postoperative spinal MRI without and with contrast enhancement, obtained within 24 h of craniotomy. Procedural problems with immediate spinal MRI were identified. Physician monitoring of the examination did not guarantee an adequate examination, and small abnormalities were missed or incompletely evaluated at the time of the MRI. Surprisingly, abnormal signal from intraspinal gas, blood, or blood breakdown products was not seen. In the absence of metastatic disease, spinal meningeal enhancement was absent. True SMD was detected, but nonneoplastic focal contrast enhancement (false positive) occurred in 11%. An unusual nonneoplastic subdural cerebrospinal fluid enhancement was seen in 3 of 13 (23%) of all patients undergoing posterior fossa craniectomies. This enhancement could hide small metastases or could be confused for SMD. Although immediate postoperative spinal MRI is potentially effective as a screening tool for the detection of SMD, we have identified some significant limitations of this technique.

A multidisciplinary clinic for the evaluation and care of children with central nervous system malformations was established at our hospital in 1963 and disbanded in 1988. Three years later, a retrospective telephone survey of myelomeningocele patients (n = 87) was used to identify the effect of clinic closing on the health and care of these patients. After the clinic was disbanded, 45-66% of myelomeningocele patients failed to have regular medical and specialty care, despite the continued availability of the same specialty care in the same location. The most significant correlation was that older patients had less frequent care; this failure in health care utilization was not related to the patients' insurance status. This lack of care is not benign. An increase in serious morbidity, including amputation and nephrectomy, was detected in those patients with the least follow-up, but not in the control group. A significant problem with coordination of the patients' care exists; neither the patient, the family, nor the local physician assumes the duties of coordinator of care. This review indicates that if a multidisciplinary clinic is disbanded, a large proportion of patients will fail to maintain adequate medical follow-up, and that significant morbidity can occur within several years. It is unrealistic to expect the continuation of effective care by merely maintaining the individual services of the disbanded clinic, without some coordinator of care.

In spastic diplegia of cerebral palsy, migration of the femoral head beyond a lateral edge of the acetabulum is a common orthopedic deformity and requires surgical treatment. We investigated whether selective dorsal rhizotomy for spastic diplegia halts or exacerbates lateral hip migration. The Reimers migration percentage computed from preoperative and postoperative hip radiographs was used as an index of the severity of lateral hip migration in all 134 hips of 67 children examined. At the time of rhizotomy, 38 patients were between 2 and 4 years of age and 29 were between 5 and 11 years of age. The follow-up period ranged from 6 to 10 months in 20 patients and from 15 to 46 months in 47 patients. Overall, the MP remained unchanged in 75% decreased in 17% and increased in 7%; thus, 93% of all hips examined were stable radiographically. Although most patients experienced postoperative hip stability, there was a significant trend for patients with greater preoperative migration to show decreased postoperative migration. The preoperative ambulatory status of patients had no impact on hip stability after dorsal rhizotomy. By the last follow-up, only 1 patient had undergone orthopedic operations for a persistent hip deformity. The results suggest that in children with spastic diplegia, selective dorsal rhizotomy halts lateral hip migration in the great majority of cases.