Treatment of the occult tethered spinal cord for neuropathic bladder: results of sectioning the filum terminale.

PURPOSE: Occult tethered cord syndrome applies to patients with signs and symptoms consistent with a caudal spinal cord malformation despite normal neuroimaging. Although several reports of successful surgical treatment exist, controversy remains with respect to patient selection and efficacy. We present a large series with excellent clinical followup, neuroimaging and urodynamic characterization. MATERIALS AND METHODS: We present our experience with 36 patients at a single institution with preoperative clinical findings, neuroimaging and urodynamics available. Postoperative outcomes were assessed clinically and with urodynamics. We determined predictive parameters to improve patient selection. RESULTS: Approximately 0.04% of pediatric urology clinic visits resulted in neurosurgical referral for the potential of an occult tethered cord. They occurred after failure of a mean of 2 years of aggressive medical management. Daytime urinary incontinence was present in 83% of patients and 47% had encopresis. Preoperative urodynamics were markedly abnormal in all patients with mean bladder capacity 55% of expected capacity. Clinical improvement in urinary symptoms was seen in 72% of patients with resolution of incontinence in 42%. Bowel symptoms improved in 88% of cases, including resolution of encopresis in 53% within 3 months of surgery. Urodynamic improvements were demonstrated in 57% of cases. We were unable to determine preoperative factors that were more likely associated with surgical success. CONCLUSIONS: In a highly select population with severe urinary and fecal dysfunction sectioning a normal-appearing filum terminale can result in significant improvement. We were unable to identify factors that may increase the chance of surgical success.

Intercenter variance in clinical trials of head trauma--experience of the National Acute Brain Injury Study: Hypothermia.

OBJECT: In a recently conducted trial of hypothermia in patients with severe brain injury, differences were found in the effects of hypothermia treatment among various centers. This analysis explores the reasons for such differences. METHODS: The authors reviewed data obtained in 392 patients treated for severe brain injury. Prerandomization variables, critical physiological variables, treatment variables, and accrual methodologies were investigated among various centers. Hypothermia was found to be detrimental in patients older than the age of 45 years, beneficial in patients younger than 45 years of age in whom hypothermia was present on admission, and without effect in those in whom normothermia was documented on admission. Marginally significant differences (p < 0.054) in the intercenter outcomes of hypothermia-treated patients were likely the result of wide differences in the percentage of patients older than 45 years of age and in the percentage of patients in whom hypothermia was present on admission among centers. The trial sensitivity was likely diminished by significant differences in the incidence of mean arterial blood pressure (MABP) less than 70 mm Hg (p < 0.001) and cerebral perfusion pressure (CPP) less than 50 mm Hg (p < 0.05) but not intracranial pressure (ICP) greater than 25 mm Hg (not significant) among patients in the various centers. Hours of vasopressor usage (p < 0.03) and morphine dose (p < 0.001) and the percentage of dehydrated patients varied significantly among centers (p < 0.001). The participation of small centers increased intercenter variance and diminished the quality of data. CONCLUSIONS: For Phase III clinical trials we recommend: 1) a detailed protocol specifying fluid and MABP, ICP, and CPP management: 2) continuous monitoring of protocol compliance; 3) a run-in period for new centers to test accrual and protocol adherence; and 4) inclusion of only centers in which patients are regularly randomized.

Evaluation and management of children younger than two years old with apparently minor head trauma: proposed guidelines.

OBJECTIVE: In children <2 years old, minor head trauma (HT) is a common injury that can result in skull fracture and intracranial injury (ICI). These injuries can be difficult to detect in this age group; therefore, many authors recommend a low threshold for radiographic imaging. Currently, no clear guidelines exist regarding the evaluation and management of head-injured infants. We sought to develop guidelines for management based on data and expert opinion that would enable clinicians to identify children with complications of HT and reduce unnecessary imaging procedures. METHODS. EVIDENCE: References addressing pediatric HT were generated from a computerized database (Medline). The articles were reviewed and evidence tables were compiled. EXPERT PANEL: The multidisciplinary panel was comprised of nine experts in pediatric HT. CONSENSUS PROCESS: A modified Delphi technique was used to develop the guidelines. Before the one meeting, panel members reviewed the evidence and formulated answers to specific clinical questions regarding HT in young children. At the meeting, guidelines were formulated based on data and expert consensus. RESULTS: A management strategy was developed that categorizes children into 4 subgroups, based on risk of ICI. Children in the high-risk group should undergo a computed tomography (CT) scan. Those in the intermediate risk group with symptoms of possible ICI should either undergo CT scan or observation. Those in the intermediate risk group with some risk for skull fracture or ICI should undergo CT and/or skull radiographs or observation. Those in the low-risk group require no radiographic imaging. CONCLUSIONS: We have developed a guideline for the evaluation of children <2 years old with minor HT. The effect of these guidelines on clinical outcomes and resource utilization should be evaluated.

Shunt infection and malfunction after augmentation cystoplasty.

PURPOSE: Maintenance of a sterile intraperitoneal environment is critical in patients with ventriculoperitoneal shunts. Recent series have reported a broad discrepancy in the rate of shunt infection (0% to 20%) following augmentation cystoplasty. The need for distal shunt revision has not been well defined. We report the incidence of shunt infection and revision at our institution after bladder augmentation. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients with myelodysplasia and a ventriculoperitoneal shunt who underwent augmentation cystoplasty since August 1990. All patients included in the study had a minimum of 12 months of followup. RESULTS: A total of 55 patients with a ventriculoperitoneal shunt secondary to myelodysplasia required augmentation cystoplasty for management of a neuropathic bladder. Standard perioperative intravenous and oral antibiotic preparation, mechanical bowel preparation and intraoperative shunt isolation were used. Mean postoperative followup was 60.4 months (range 12 to 111). One patient presented with an extruded peritoneal shunt tip and positive cultures from cerebrospinal fluid and urine. Bladder perforation occurred in 2 patients and the shunt was empirically externalized. Revision was required for 5 (9%) distal shunt obstructions, including 1 cerebrospinal fluid pseudocyst. CONCLUSIONS: The incidence of shunt infection after augmentation cystoplasty is low (less than 2% in this large series), and presence of a ventriculoperitoneal shunt should not preclude bladder augmentation. Meticulous perioperative and intraoperative preparation contributes to the low rate of adverse events. Although the rate of distal revision after augmentation is significant, it does not exceed the reported distal failure rate for ventriculoperitoneal shunts in children without a history of urological surgery.

Tumor-related epilepsy in children.

A 10-year retrospective review of 15 children with cerebral tumors and seizures was conducted to study the factors responsible for delay in the diagnosis of tumors and to assess outcome following surgery. Mean duration of seizures prior to surgery was 37 months. Ninety-three percent had no focal neurologic deficits. Head computed tomography was abnormal in 64%, whereas magnetic resonance imaging was abnormal in all patients. Electroencephalography showed focal abnormalities ipsilateral to the tumor in 73%. There was no surgical mortality. Eighty percent were seizure free or had rare seizures following surgery. Factors contributing to a delayed diagnosis of the brain tumor included a nonfocal neurologic examination and delay in obtaining an appropriate neuroimaging study. We believe that head magnetic resonance imaging should be the investigation of choice in partial epilepsies.

Lack of effect of induction of hypothermia after acute brain injury.

BACKGROUND: Induction of hypothermia in patients with brain injury was shown to improve outcomes in small clinical studies, but the results were not definitive. To study this issue, we conducted a multicenter trial comparing the effects of hypothermia with those of normothermia in patients with acute brain injury. METHODS: The study subjects were 392 patients 16 to 65 years of age with coma after sustaining closed head injuries who were randomly assigned to be treated with hypothermia (body temperature, 33 degrees C), which was initiated within 6 hours after injury and maintained for 48 hours by means of surface cooling, or normothermia. All patients otherwise received standard treatment. The primary outcome measure was functional status six months after the injury. RESULTS: The mean age of the patients and the type and severity of injury in the two treatment groups were similar. The mean (+/-SD) time from injury to randomization was 4.3+/-1.1 hours in the hypothermia group and 4.1+/-1.2 hours in the normothermia group, and the mean time from injury to the achievement of the target temperature of 33 degrees C in the hypothermia group was 8.4+/-3.0 hours. The outcome was poor (defined as severe disability, a vegetative state, or death) in 57 percent of the patients in both groups. Mortality was 28 percent in the hypothermia group and 27 percent in the normothermia group (P=0.79). The patients in the hypothermia group had more hospital days with complications than the patients in the normothermia group. Fewer patients in the hypothermia group had high intracranial pressure than in the normothermia group. CONCLUSIONS: Treatment with hypothermia, with the body temperature reaching 33 degrees C within eight hours after injury, is not effective in improving outcomes in patients with severe brain injury.

Near infrared spectroscopy (NIRS) distinguishes seizure types.

Near infrared spectroscopy (NIRS) is a noninvasive method for bedside measurement of cerebral oxygenation (SaO(2)). The purpose of this study was to establish differences in SaO(2)for complex partial seizures (CPS) and rapidly secondarily generalized CPS (RCPS). We studied eight adults with medically refractory epilepsy undergoing evaluation for temporal lobectomy. We continually measured cerebral SaO(2)via a Somanetic Invos 3100a cerebral oximeter, pre-ictal (5 minutes), ictal, immediate (30 seconds) post-ictal, and late post-ictal (5 minutes after ictus). Seventeen seizures (12 CPS, four RCPS and one subclinical) were recorded in eight patients. The percentage change in cerebral SaO(2)from pre-ictal to ictal periods was derived. Cerebral SaO(2)increased (percentage change, mean: 16.6, SD: 13.9) for CPS and decreased (percentage change, mean: 51.1, SD: 18.1) for RCPS. No change in cerebral oximetry was recorded for the subclinical seizure. Post-ictal (immediate and late) increase in cerebral SaO(2)was seen for 11 of the 17 seizures (nine CPS and two RCPS). Peripheral SaO(2)rose greater than 93% for all CPS and the subclinical seizure, but decreased between 78 and 84% during RCPS. These results suggest NIRS distinguishes cerebral SaO(2)patterns between CPS and RCPS. The decrease in peripheral SaO(2), however, may account for the decrease in cerebral SaO(2)seen in generalized seizures.

Arachnoid cyst rupture with concurrent subdural hygroma.

Arachnoid cysts (ACs) are relatively common intracranial mass lesions, which occur most often in the middle cranial fossa. While these lesions can present as a mass lesion, many are asymptomatic. Rarely, posttraumatic or spontaneous rupture of ACs can result in intracystic hemorrhage, subdural hematoma or subdural hygroma. We have encountered two cases of ruptured arachnoid cysts that resulted in subdural hygromas. Both patients harbored middle cranial fossa cysts and suffered mild closed head injuries. The presentation, radiographic findings and surgical management of these patients as well as the association between ACs and subdural hygromas are described.

Phase II evaluation of interferon-alpha-2a for progressive or recurrent craniopharyngiomas.

OBJECT: Craniopharyngiomas originate from the same cells as squamous cell skin carcinoma, which can be treated successfully with interferon-alpha (IFNalpha)-2a. The authors evaluated the activity and toxicity of systemic IFN in young patients with craniopharyngiomas. METHODS: Fifteen patients between the ages of 4.2 and 19.8 years who had progressive or recurrent craniopharyngiomas were enrolled in this study. Nine of these patients had never received external-beam radiation therapy. Therapy consisted of 8,000,000 U/m2 IFNalpha-2a administered daily for 16 weeks (induction phase) followed by the same dose three times per week for an additional 32 weeks (maintenance phase). Of the 12 patients who could be evaluated, radiological studies demonstrated a response to treatment in three with predominantly cystic tumors (one minor response, one partial response, and one complete response); one of these patients also showed improvement in visual fields. The size of the cystic component of the tumors often increased temporarily during the first several months of therapy. Three patients met the criteria for progressive disease during therapy. The median time to progression was 25 months. The need for radiation therapy in patients treated with IFN was delayed for 18 to 35 months (median 25 months) in six patients. All patients developed transient flulike symptoms shortly after receiving the first dose of IFN. Other toxicities (predominantly hepatic, neurological, and cutaneous) were seen in nine (60%) of the 15 patients during the first 8 weeks of treatment but resolved after temporary discontinuation and/or dose reduction. CONCLUSIONS: Interferon-alpha-2a is active against some childhood craniopharyngiomas; its toxicity precludes administration of high daily doses, and the optimum dose level and schedule remain to be defined.

Chiari III malformation treated with CSF diversion and delayed surgical closure.

Chiari III malformations are extremely rare hindbrain malformations that are associated with a high early mortality rate, or severe neurologic deficits in the survivors. The preferred treatment is early operative closure and CSF shunting. We report a case of a newborn infant with a Chiari III malformation with displacement of the brainstem and cerebellum into the cervical encephalocele which precluded immediate operative closure of the defect. Instead, a ventriculoperitoneal shunt was placed and the patient was followed with serial imaging studies. The child survived. The shunt allowed the brainstem and cerebellum to regress into the cervical spinal canal as the dilated cerebral aqueduct and fourth ventricle decompressed. A delayed closure of the cervical encephalocele was performed at 30 months of age. Cerebrospinal fluid diversion with delayed closure may be an option for large lesions.

Brain tissue pressure gradients are dependent upon a normal spinal subarachnoid space.

Reports from our laboratory have shown that regional brain tissue pressure (RBTP) gradients develop in response to supratentorial but not posterior fossa extradural masses. We undertook this experiment to discover the mechanism of this differing response. RBTP was measured in the right and left frontal lobes (RF, LF), temporal lobes (RT, LT), midbrain (MB), and cerebellum (CB) of ten pigs. Balloons were expanded in the epidural space at C2 to occlude the subarachnoid space. A temporal extradural mass was expanded incrementally. The C2 balloon was deflated after temporal mass expansion. Expansion of the cervical balloon resulted in a homogeneous rise in RBTP. Expansion of the temporal mass resulted in the development of small RBTP gradients with the following relationship: RT > LT = LF > RF = CB > MB. In comparison with a previous series of animals without cervical balloons, animals in this series demonstrated higher global ICP in response to equal size masses and smaller RBTP gradients. Cervical balloon deflation resulted in decreased global ICP and increased RBTP gradients. The development of RBTP gradients in response to expanding supratentorial masses therefore appears to be at least partially dependent upon the presence of a normal communication between the supratentorial space and the spinal subarachnoid space.

Intracranial pressure: current status in monitoring and management.

One of the most frequently occurring questions in the neurological critical care of children involves the indications for measurement of intracranial pressure (ICP) and the appropriate therapies for abnormally elevated ICP. Advances in monitoring technology have improved the safety and accuracy of ICP measurement. Clinical and basic research into the mechanisms of brain swelling and the efficacy of various therapies, especially in the realm of traumatic brain injury, has allowed the development of rational and specific treatment strategies for elevated ICP. For several diseases, the ability to measure and manage ICP has resulted in marked improvements in outcomes. This article reviews the indications for, and recommended methods of, measuring ICP in children and discusses the status of therapies commonly used to control elevated ICP.

Regional brain tissue pressure gradients created by expanding extradural temporal mass lesion.

A porcine model of regional intracranial pressure was used to compare regional brain tissue pressure (RBTP) changes during expansion of an extradural temporal mass lesion. Measurements of RBTP were obtained by placing fiberoptic intraparenchymal pressure monitors in the right and left frontal lobes (RF and LF), right and left temporal lobes (RT and LT), midbrain (MB), and cerebellum (CB). During expansion of the right temporal mass, significant RBTP gradients developed in a reproducible pattern: RT > LF = LT > RF > MB > CB. These gradients appeared early, widened as the volume of the mass increased, and persisted for the entire duration of the experiment. The study indicates that RBTP gradients develop in the presence of an extradural temporal mass lesion. The highest RBTP was recorded in the ipsilateral temporal lobe, whereas the next highest was recorded in the contralateral frontal lobe. The RBTP that was measured in either frontal lobe underestimated the temporal RBTP. These results indicated that if a frontal intraparenchymal pressure monitor is used in a patient with temporal lobe pathology, the monitor should be placed on the contralateral side and a lower threshold for therapy of increased intracranial pressure should be adopted. Furthermore, this study provides further evidence that reliance on a single frontal intraparenchymal pressure monitor may not detect all areas of elevated RBTP.

Behavioural adjustment and parental stress associated with closed head injury in children.

Parental stress and parental perception of children's behavioural problems were determined for 25 caretakers of children with closed head injury. Compared to normative samples a greater proportion of parents in this study were more stressed, and thought that their children were more behaviourally impaired. In contrast to previous studies, injury severity was not related to behavioural impairment. Parental stress was related to perceived behavioural impairment for the brain-injured sample. When compared to low-stressed parents (n = 14), high-stressed parents (n = 11) described their children as more aggressive and with more thought disorders and attention problems. Time since injury, age at injury, number of siblings, and mother's age were not different between the high- and low-stressed groups. Low income and less education were associated with the high stress levels in these parents. Test-retest data showed that, over time, parents perceived their brain-injured children as less behaviourally impaired.

Brain tissue pressure gradients created by expanding frontal epidural mass lesion.

A porcine model was used to study the regional intracranial pressure (ICP) differences caused by a frontal mass lesion. Intraparenchymal ICP monitors were placed in the right and left frontal lobes, right and left temporal lobes, midbrain, and cerebellum. A frontal epidural mass lesion was created by placing a balloon catheter through a burr hole into the right frontal epidural space. A computer was used to acquire data from all monitors at 50-msec intervals. The balloon was expanded by 1 cc over a period of 1 second every 5 minutes and maximum pressure immediately before and during expansion was determined for each balloon volume at each site. Prior to expansion of the mass, the morphology of the cerebellum pressure tracing was different from that seen in all supratentorial regions. Also, pressures in the midbrain, at baseline, were slightly but significantly lower than pressures in the frontal and temporal regions. During expansion of the mass, a pressure differential that increased as the size of the mass increased developed between intracranial regions. Furthermore, the regional pressures were found to vary in a consistent fashion expressed by the formula RF=LF>RT=LT>MB>CB, in which RF and LF are the right and left frontal lobes, RT and LT are the right and left temporal lobes, MR in the midbrain, and CB is the cerebellum. The study shows that an expanding epidural mass reproducibly results in a gradient of brain parenchymal pressure. This gradient results in parenchymal pressures that are significantly different in each region of the brain depending on the proximity of that region to the epidural mass. The results of this study have implications for clinical ICP monitoring and therapy.

Cloacal exstrophy: the neurological implications.

Congenital anomalies commonly accompany the abdominal wall defects of cloacal exstrophy with an incidence as high as 100% in some series. The urological literature cites an incidence of vertebral and/or spinal cord anomalies in 75% of cases. We reviewed the records of the 17 patients with cloacal exstrophy treated at our institution since 1978. Abnormalities of the vertebral column or spinal cord were identified in 16 patients, including 11 of 12 (92%) fully evaluated by myelography, computerized tomography or magnetic resonance imaging of the lumbosacral spinal cord. Nine patients had a lipomeningocele and 4 had a lipomyelocystocele. Spinal exploration, repair and cord untethering were done in 11 patients of whom 2 subsequently underwent reoperation for re-tethering the cord. A total of 15 patients is ambulatory although 5 require lower extremity braces. The incidence of spinal cord or vertebral anomalies in our patients with cloacal exstrophy approaches 100%, which is higher than commonly cited in the urological literature. We recommend magnetic resonance imaging of the spinal cord as part of the initial evaluation of newborns with cloacal exstrophy. Lifelong attention to the risk of spinal cord tethering can optimize neurological outcome in affected individuals.