Traumatic brain injury in infants: the phenomenon of subdural hemorrhage with hemispheric hypodensity (“Big Black Brain”)

Clinical and experimental studies of traumatic brain injury during immaturity have been far less numerous than those involving adults, and many questions remain about differences in injury responses among patients of different ages. This chapter reviews a distinctive injury pattern common in infants, the so-called "big black brain" response to acute subdural hematoma. The pathophysiology of this injury remains incompletely understood. Insights from both clinical observation and experimental studies have helped to clarify the probable causes of this injury pattern, which appears to require a combination of stressors during a particular period of maturation.

Large animal models of traumatic injury to the immature brain

Large animal models have been used much less frequently than rodent models to study traumatic brain injury. However, large animal models offer distinct advantages in replicating specific mechanisms, morphology and maturational stages relevant to age-dependent injury responses. This paper reviews how each of these features is relevant in matching a model to a particular scientific question and discusses various scaling strategies, advantages and disadvantages of large animal models for studying traumatic brain injury in infants and children. Progress to date and future directions are outlined.

Evaluation and management of shunt infections in children with hydrocephalus

Shunt infections constitute one of the main risks of shunt surgery for hydrocephalus, which is the single most common type of surgery performed by pediatric neurosurgeons. Infectious complications are responsible for increased morbidity and mortality, lengthy hospitalizations, and high cost. Most modern series report infection rates approaching 10% of all shunt procedures. Despite the high incidence of this complication, optimal management is still unknown, and research on prevention has been hampered by single-institution series and small numbers. This article will review the history, causes, presentation, management, and outcome from shunt infections in children. Pitfalls in diagnosis and management will be reviewed. Finally, prevention strategies and research questions still remaining in this area will be outlined.

Dystrophic neuritic processes in epileptic cortex

Cortical dysplasia is a frequent finding in cortical resections from children with refractory epilepsy. Diagnostic criteria and a classification scheme for cortical dysplasia has been proposed, though the relationship between specific cortical dysplasia features and their causal relationship with epilepsy is poorly understood. We reviewed 28 surgical resections from children and identified a common and easily recognized feature of cortical dysplasia: maloriented, misshapen and occasionally coarse neurofilament stained process forming a dystrophic neuritic background. The dystrophic neuritic background was associated with other features of cortical dysplasia in all 28 patients with cortical dysplasia, 26 with refractory epilepsy and 2 patients with other neurologic diagnoses. In seven children with refractory epilepsy due to other pathologic diagnosis such as vascular or glial lesions, the dystrophic neuritic background was only found in one patient with a ganglioglioma and other features suggestive of an associated cortical dysplasia. Our data indicate that a dystrophic neuritic background is a common and relatively specific neuropathologic finding in cortical dysplasia.

Functional magnetic resonance imaging of the primary somatosensory cortex in piglets

OBJECT

The piglet is an excellent model for the developing human brain, and has been used increasingly in various centers for studies of traumatic brain injury and other insults. Unlike rodent or primate models, however, there are few behavioral scales for the piglet, and the available ones are used to test general responsiveness rather than specific functional outcome. The differing behavioral repertoires of animals of different ages provide an additional challenge when age-dependent injury responses are compared. To overcome these experimental limitations of piglets in brain injury research, the authors developed a functional magnetic resonance (fMR) imaging paradigm that can be used to track recovery in the somatosensory cortex over time in anesthetized animals of different ages.

METHODS

Fifteen fMR imaging studies in eight piglets were performed before and after scaled cortical impact injury to the primary somatosensory cortex subserving snout sensation. Specific anesthetic and imaging protocols enabled visualization of cortical activation, and comparison with somatosensory evoked potentials obtained before and after injury was obtained. A piglet brain template for group-level analysis of these data was constructed, similar to the fMR imaging techniques used in humans, to allow for group comparisons and longitudinal change analysis over time.

CONCLUSIONS

Loss of function in a specifically traumatized cortical region and its subsequent recovery over time can now be demonstrated visually by fMR imaging in the piglet. Besides its value in understanding intrinsic recovery mechanisms and plasticity at different ages, this functional outcome measure will enable the use of the piglet model in treatment trials specifically designed for the immature brain.

Acquired Chiari malformation type I following fractionated radiation therapy to the anterior skull base in a 20-month-old boy. Case report

The authors present the case of a 20-month-old boy who underwent fractionated radiation therapy to the paranasal sinuses and anterior skull base during treatment for nasopharyngeal parameningeal rhabdomyosarcoma. Subsequent magnetic resonance imaging demonstrated progressive development of a Chiari malformation Type I (CM-I) and partial hypoplasia of the posterior fossa. Since the tonsillar herniation was discovered, the child, now 3 years old, remains asymptomatic except for mild, intermittent neck discomfort. For the time being, his family has elected for him to undergo clinical and neuroimaging follow up. The authors believe this is the first report of a progressive acquired CM-I after cranial irradiation in the pediatric population.

Chiari malformation Type I and a dolichoodontoid process responsible for sudden cardiorespiratory arrest. Case report

The authors present the case of an 11-year-old girl who fell from standing height and experienced sudden cardiorespiratory arrest. A Chiari malformation Type I and a dolichoodontoid process were identified, and a brainstem contusion was found that correlated with the patient's clinical signs and symptoms. The authors hypothesize that the dolichoodontoid in a compromised craniocervical space created a contusion in the apposing brainstem at the time of head impact. The patient was left with permanent vocal cord paresis and spastic quadriparesis. Awareness of this rare occurrence is important in managing these congenital abnormalities and in assessing the risk of deterioration.

Optic radiation involvement in optic pathway gliomas in neurofibromatosis

PURPOSE

Optic pathway gliomas (pilocytic astrocytomas) in neurofibromatosis type 1 (NF-1) typically involve some combination of the optic nerves, chiasm, or optic tracts. Involvement of the optic radiations is rare.

DESIGN

This paper describes seven patients with NF-1 with gliomas involving the pregeniculate optic pathway in addition to the optic radiations.

METHODS

A retrospective database review was made of all patients with NF-1 and optic pathway gliomas seen by one of the authors (G.T.L.) at the Children's Hospital of Philadelphia from July 1993 to October 2001. Patients with involvement of pregeniculate optic pathway and the optic radiations were identified. From November 2001 to February 2003, patients were sought prospectively. Cases were also identified from the practice of another author (M.C.B.) at Arkansas Children's Hospital.

RESULTS

Four patients from Children's Hospital of Philadelphia (three of 83 total NF-1/optic pathway gliomas from July 1993 to October 2001 and one prospectively) and three from Arkansas Children's Hospital were identified. Two had expanding mass lesions within the white matter of the temporal or parietal lobes, which were histopathologically demonstrated to be pilocytic astrocytomas. The other five had radiographic involvement of the optic radiations but did not undergo biopsy. In three of the cases the vision was 20/200 or worse in each eye.

CONCLUSIONS

Optic pathway gliomas in NF-1 may rarely involve the optic radiations. Optic radiation involvement may signal a more aggressive optic pathway glioma in patients with neurofibromatosis-1.

Split cord malformation as a cause of tethered cord syndrome in a 78-Year-old female

A 78-year-old woman presented for evaluation of back pain, urinary dysfunction, leg weakness and progressive equinovarus foot deformity. She reported that shortly after her birth in 1924, she underwent resection of a subcutaneous 'cyst' in the lower lumbar area. Seven years prior to evaluation at our institution, she had undergone bilateral total knee arthroplasty for osteoarthritis. After the procedure, she began to experience severe low back pain that radiated into her legs. Weakness of the foot inverters, urinary dysfunction and worsening bilateral equinovarus foot deformity developed in the years following the surgery. MRI revealed a split cord malformation with a tethered spinal cord. Because of the patient's age and poor medical condition, her symptoms were managed conservatively. This case demonstrates symptomatic deterioration in an elderly patient with a tethered spinal cord after many years of clinical stability.

Magnetic resonance imaging studies of age-dependent responses to scaled focal brain injury in the piglet

OBJECT

Whether the brain differs in its response to traumatic injury as a function of age remains unclear. To further investigate the age-dependent response of the brain to mechanical trauma, a cortical contusion model scaled for brain growth during maturation was used to study the evolution of injury over time as demonstrated on serial magnetic resonance (MR) imaging studies in piglets of different ages.

METHODS

Sixteen Yorkshire piglets received scaled cortical contusions. Animals were either 5 days (six animals), 1 month (five animals), or 4 months (five animals) of age at injury. These ages correspond developmentally to human infants, toddlers, and early adolescents, respectively. Serial MR imaging examinations, including fluid-attenuated inversion-recovery and T1-, T2-, and diffusion-weighted sequences were performed at 24 hours, 1 week, and 1 month after injury. Lesions were quantified and expressed as a ratio of the lesion volume divided by the volume of the uninjured hemisphere for each animal and each MR sequencing. Differences in relative lesion volume among the varied ages at a single time point and in lesion volume over time at each age were compared. In addition, the relationship between age and evolution of injury were analyzed using a two-compartment mathematical model. Histological features were examined at 1 month postinjury. Despite comparable injury inputs, the youngest animals had lesions whose volumes peaked earlier and resolved more quickly than those in older animals. The intermediate-age piglets (toddler) had the most pronounced swelling of any age group, and the oldest piglets (adolescent) had the latest peak in lesion volume.

CONCLUSIONS

Scaled cortical contusions in piglets demonstrated age-dependent differences in injury response, both in magnitude and time course. These observations may shed light on development-related trauma response in the gyrencephalic brain.

Anthropomorphic simulations of falls, shakes, and inflicted impacts in infants

OBJECT

Rotational loading conditions have been shown to produce subdural hemorrhage and diffuse axonal injury. No experimental data are available with which to compare the rotational response of the head of an infant during accidental and inflicted head injuries. The authors sought to compare rotational deceleration sustained by the head among free falls, from different heights onto different surfaces, with those sustained during shaking and inflicted impact.

METHODS

An anthropomorphic surrogate of a 1.5-month-old human infant was constructed and used to simulate falls from 0.3 m (1 ft), 0.9 m (3 ft), and 1.5 m (5 ft), as well as vigorous shaking and inflicted head impact. During falls, the surrogate experienced occipital contact against a concrete surface, carpet pad, or foam mattress. For shakes, investigators repeatedly shook the surrogate in an anteroposterior plane; inflicted impact was defined as the terminal portion of a vigorous shake, in which the surrogate's occiput made contact with a rigid or padded surface. Rotational velocity was recorded directly and the maximum (peak-peak) change in angular velocity (delta theta(max)) and the peak angular acceleration (theta(max)) were calculated. Analysis of variance revealed significant increases in the delta theta(max) and theta(max) associated with falls onto harder surfaces and from higher heights. During inflicted impacts against rigid surfaces, the delta theta(max) and theta(max) were significantly greater than those measured under all other conditions.

CONCLUSIONS

Vigorous shakes of this infant model produced rotational responses similar to those resulting from minor falls, but inflicted impacts produced responses that were significantly higher than even a 1.5-m fall onto concrete. Because larger accelerations are associated with an increasing likelihood of injury, the findings indicate that inflicted impacts against hard surfaces are more likely to be associated with inertial brain injuries than falls from a height less than 1.5 m or from shaking.

Complications of invasive monitoring used in intractable pediatric epilepsy

Invasive monitoring for intractable epilepsy is useful when the epileptogenic focus is in question even after an extensive noninvasive presurgical evaluation, or when the epileptogenic focus is located in or near eloquent cortex. From June 1989 to June 2001 at the Children's Hospital of Philadelphia, 64 children with intractable epilepsy underwent 67 invasive monitoring procedures as part of their presurgical evaluation. The average age at implantation was 10 years. In all but two cases, subdural strips and grids were used. Depth electrodes, when used, were placed stereotactically or under direct vision. The average duration of the monitoring period was 5.87 days. Every patient had intradural cultures sent during removal of the electrodes, and lumbar punctures were performed in 15 patients. Twenty-one patients had at least one episode of a CSF leak. Of the 67 patients, 10 had positive intradural cultures, only 1 of whom had a positive lumbar puncture and none of whom developed clinically significant meningitis. No clinically relevant hemorrhages occurred as a result of the invasive monitoring. One patient did have a transient visual field loss after placement of an occipital grid. While CSF leaks are common after invasive monitoring despite precautions, clinically significant CSF infections are uncommon and appear to be unrelated to the duration of monitoring, the occurrence of a CSF leak or the length of time the patient is on perioperative antibiotics. We conclude that invasive monitoring for intractable epilepsy is generally safe.

Recovery of language after left hemispherectomy in a sixteen-year-old girl with late-onset seizures

Hemispherectomy is a very effective surgical treatment for intractable seizures that occur in the setting of Rasmussen's syndrome. The decision of when to perform a dominant hemispherectomy depends greatly on how late the surgeon believes some shift in language to the nondominant hemisphere can occur. We report a right-handed patient with Rasmussen's syndrome who underwent a left hemispherectomy at the age of 16 and has had excellent control of her seizures and remarkable language recovery. Our results indicate that dominant hemispherectomy in adolescence in the setting of late-onset seizures and Rasmussen's syndrome in the profoundly aphasic patient does not commit the patient to the prognosis of a fixed language deficit.

Overview and clinical presentation of inflicted head injury in infants

Child abuse is a widespread phenomenon which is increasingly recognized in our culture. In this chapter, the epidemiology, clinical presentation, and commonly associated injuries are reviewed. The typical presentation and clinical assessment of inflicted head injury is also described.

Metachronous Epstein-Barr virus-related smooth muscle tumors in a child after heart transplantation: case report and review of the literature

Soft tissue tumors are uncommon manifestations of Epstein-Barr virus (EBV) infection in patients who have had transplants. The authors report 2 metachronous EBV-containing smooth muscle tumors in a child who had a heart transplant, and review the literature on posttransplant soft tissue tumors.

Role of MAP kinase pathways in primitive neuroectodermal tumors

Mitogen-activated protein kinase and Phosphatidylinositol-3 kinase/Akt-mediated signaling pathways play a major role in controlling cell proliferation, differentiation and cell death. Phosphorylation and dephosphorylation of their specific Thr/Tyr residues is critical in determining their activity. We determined the expression pattern and activity of MAP kinases and Akt in Primitive Neuroectodermal Tumors (PNETs). The kinase activity of extracellular signal-regulated kinase (ERK) was higher in both primary tumors and cell lines, as evident from the increased phosphorylation of ERK1 and ERK2. We did not observe the activation of C-jun N-terminal kinase (JNK) or p38 MAPK The expression of Raf-1, a kinase acting upstream of ERK, was significantly increased in primary tumors compared to normal brain. The PI-3 kinase-activated phosphorylation of Akt was also higher in primary tumors. These results suggest that activation of the Raf-1/ERK module of the MAP kinase pathway play an important role in PNETs.

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.

Differential expression of glutamate and GABA-A receptor subunit mRNA in cortical dysplasia

OBJECTIVE

Focal cortical dysplasia is characterized by disorganized cortical lamination, dysplastic and heterotopic neurons, and an association with epilepsy. The contribution that dysplastic and heterotopic neurons make to epileptogenesis in focal cortical dysplasia is unknown and the phenotype of these cells may be distinct. The authors hypothesized that the expression of genes encoding glutamatergic (glutamate [GluR] and N-methyl-D-aspartate NMDA receptors [NR]) and gamma-aminobutyric acid A receptor (GABA(A)R) subunits is distinct in dysplastic and heterotopic neurons and that changes in receptor gene expression could be defined in a cell-specific pattern.

METHODS

Single immunohistochemically labeled dysplastic and heterotopic neurons were microdissected from human focal cortical dysplasia specimens obtained during epilepsy surgery. Pyramidal neurons were microdissected from postmortem control cortex and from temporal cortex without dysplasia resected during temporal lobectomy. Poly (A) messenger RNA (mRNA) from single neurons was amplified, radiolabeled, and used to probe complementary DNA (cDNA) arrays containing GluR(1-6), NR(1A,1B), NR(2A-D), and GABA(A)Ralpha(1-6), and -Rbeta(1-3) subunit cDNAS: The relative hybridization intensities of each mRNA-cDNA hybrid were quantified by phosphorimaging.

RESULTS

GluR, NR, and GABA(A)R subunit mRNA expression did not differ between control neurons and nondysplastic epilepsy specimens. Expression of GluR(4), NR(2B), and NR(2C) subunit mRNA was increased, and NR(2A) and GABA(A)Rbeta(1) subunit mRNA was decreased in dysplastic compared with pyramidal and heterotopic neurons. In contrast, GABA(A)Ralpha(1), -Ralpha(2), and -Rbeta(2) as well as GluR(1) mRNA levels were reduced in both dysplastic and heterotopic neurons.

CONCLUSIONS

Differential expression of GluR, NR, and GABA(A)R mRNA in dysplastic and heterotopic neurons demonstrates cell specific gene transcription changes in focal cortical dysplasia. These results suggest that dysplastic and heterotopic neurons may be pharmacologically distinct and make differential contributions epileptogenesis in focal cortical dysplasia.

Maturation-dependent response of the piglet brain to scaled cortical impact

OBJECT

The goal of this study was to investigate the relationship between maturational stage and the brain's response to mechanical trauma in a gyrencephalic model of focal brain injury. Age-dependent differences in injury response might explain certain unique clinical syndromes seen in infants and young children and would determine whether specific therapies might be particularly effective or even counterproductive at different ages.

METHODS

To deliver proportionally identical injury inputs to animals of different ages, the authors have developed a piglet model of focal contusion injury by using specific volumes of rapid cortical displacement that are precisely scaled to changes in size and dimensions of the growing brain. Using this model, the histological response to a scaled focal cortical impact was compared at 7 days after injury in piglets that were 5 days, 1 month, and 4 months of age at the time of trauma. Despite comparable injury inputs and stable physiological parameters, the percentage of hemisphere injured differed significantly among ages, with the youngest animals sustaining the smallest lesions (0.8%, 8.4%, and 21.5%, for 5-day-, 1-month-, and 4-month-old animals, respectively, p = 0.0018).

CONCLUSIONS

These results demonstrate that, for this particular focal injury type and severity, vulnerability to mechanical trauma increases progressively during maturation. Because of its developmental and morphological similarity to the human brain, the piglet brain provides distinct advantages in modeling age-specific responses to mechanical trauma. Differences in pathways leading to cell death or repair may be relevant to designing therapies appropriate for patients of different ages.

CHOP Infant Coma Scale ("Infant Face Scale"): a novel coma scale for children less than two years of age

The Glasgow Coma Scale (GCS) is the most frequently used tool worldwide for assessing the severity of neurologic injury after brain trauma, although applying this scale to infants and younger children can be problematic. The CHOP Infant Coma Scale, or Infant Face Scale (IFS), is a novel scale for children under 2 years of age which differs from other pediatric coma scales in the following ways: (1) it relies on objective behavioral observations; (2) it assesses cortical as well as brainstem function; (3) it parallels the GCS in scoring but is based on infant-appropriate behaviors; and (4) it can be applied to intubated patients. We report the results of a prospective study designed to compare interrater reliability between the IFS and GCS in children less than 2 years of age. Seventy-five hospitalized children less than 2 years of age were assessed simultaneously by a pair of observers, representing a spectrum of health care professionals, who scored the children using both the IFS and GCS. Interrater reliability for each pair of observers for each scale was assessed using the kappa statistic. A second series of 10 infants in the intensive care unit with specific diagnoses of acute traumatic or hypoxic/ischemic brain injury were similarly assessed. In the 75 hospitalized infants with a variety of diagnoses, interrater reliability for the GCS was in the "almost perfect," "slight," and "fair" range for the eye-opening, motor, and verbal subtests, respectively. In contrast, the IFS showed interrater reliability in the "almost perfect," "substantial," and "almost perfect" ranges for the three subtests. When applied to infants in an intensive care unit with acute traumatic brain injury or hypoxia/ischemia, the GCS interrater reliability scores were in the "fair" range, while the IFS scores were in the "almost perfect" range. The IFS demonstrates improved interrater reliability in direct comparison to the GCS, particularly in the "verbal/face" component where most pediatric coma scales are deficient. The IFS may prove to be a simple and practical bedside index of brain injury severity in children less than two years of age.

Age-related differences in acute physiologic response to focal traumatic brain injury in piglets

INTRODUCTION

The goal of the present study was to determine whether age-related differences in the acute physiologic response to scaled cortical impact injury contribute to differences in vulnerability to traumatic brain injury (TBI).

METHODS

Heart rate (HR), mean arterial pressure (MAP), brain temperature (BrT) and cerebral blood flow (CBF) were measured in 22 piglets (7 of age 5 days, 8 of age 1 month, 7 of age 4 months) at baseline and for 3 h following scaled cortical impact injury.

RESULTS

There were no age-dependent variations from baseline in HR, MAP or BrT following injury. CBF increased in the 5-day-old animals following injury while CBF in the 1- and 4-month-old animals decreased following injury (p = 0.0049).

CONCLUSION

CBF was shown to have a significant age-dependent response to TBI with the youngest animals exhibiting increased CBF following injury.

Tonsillar pain mimicking glossopharyngeal neuralgia as a complication of vagus nerve stimulation: case report

An adolescent girl presented with severe, lancinating tonsillar pain exacerbated by swallowing 6 weeks after initiation of left vagus nerve stimulation for intractable epilepsy. Her symptoms mimicked those seen in glossopharyngeal neuralgia and were relieved by temporary cessation of stimulation. Gradual reinstitution of therapy with alteration in stimulus parameters resulted in improved seizure control as well as cessation of pain symptoms. Direct stimulation of the vagus nerve may result in vagoglossopharyngeal neuralgia, which, in this case, was amenable to stimulus modification.

Retinal hemorrhages caused by accidental household trauma

Traumatic retinal hemorrhages in young children are considered pathognomonic of child abuse. We identified 3 children with unilateral retinal hemorrhages caused by accidental household trauma. The hemorrhages were ipsilateral to intracranial hemorrhage and isolated to the posterior retinal pole.

Extrarenal nephroblastic proliferation in spinal dysraphism. A report of 4 cases

Four cases of extrarenal nephrogenic proliferation in the sacrococcygeal region with spinal dysraphism are presented. In two of the cases, features of Wilm's or incipient Wilm's tumor were present. The previous literature on sacrococcygeal nephrogenic tissue is reviewed, and the impact of these findings on the histogenesis of extrarenal sacrococcygeal Wilm's tumor is discussed.

Language-related cognitive declines after left temporal lobectomy in children

Presented is a case series demonstrating that clinically significant language-related cognitive declines not detected by intelligence quotient (IQ) testing occur after left temporal lobectomy in school-aged children. In this series, comprehensive preoperative and postoperative neuropsychologic evaluations were completed in eight school-aged patients who underwent temporal lobectomy (five left, three right) for temporal lobe epilepsy. Mean age at surgery was 13 years, 11 months +/- 2 years, 1 month. Testing included measurement of IQ, verbal learning, naming, visual memory, sight word recognition, reading comprehension, and calculation. All five left temporal lobectomy patients demonstrated significant language-related cognitive declines on postoperative neuropsychologic testing, including deficits in verbal IQ (one patient), verbal learning (four patients), naming (one patient), and reading comprehension (one patient). These deficits were clinically evident in four of the five left temporal lobectomy patients, leading to declines in educational performance. IQ testing alone did not reliably identify these deficits. No significant declines were found after surgery in three right temporal lobectomy patients. Average or high preoperative functioning may have predisposed patients to postoperative deficits in this series, whereas magnetic resonance imaging or pathologic abnormalities did not protect against postoperative deficits. Outcome studies of temporal lobectomy in childhood should use comprehensive neuropsychologic testing to identify cognitive deficits.

Imaging studies in a unique familial dysmyelinating disorder

We report the imaging findings in five patients with a unique dysmyelinating disorder. MR studies of these infants showed obstructive hydrocephalus caused by mass effect produced by an enlarged cerebellum. The white matter of an enlarged cerebrum and cerebellum showed delayed myelination. Proton spectroscopy showed normal N-acetylaspartate (NAA) levels. While the dysmyelinating disorder was clearly differentiated from Canavan disease by an absence of elevated NAA and differing histopathologic findings and autosomal-dominant inheritance pattern, there were similarities to this disease in the presentation and, to some extent, in the initial imaging findings.

Treatment of villous hypertrophy of the choroid plexus by endoscopic contact coagulation

Villous hypertrophy of the choroid plexus (VHCP) is a condition characterized by overproduction of cerebrospinal fluid by bilaterally symmetric and enlarged, yet histologically normal, choroid plexi. Medical and surgical therapy have been met with variable success. Traditional shunting procedures often result in failure to correct the underlying problem as well as failure to absorb the large volume of fluid produced. Craniotomy for open surgical resection of the choroid is associated with considerable morbidity. The authors describe a technique of endoscopic contact coagulation as an effective and safe treatment of VHCP. A 14-month-old hydrocephalic girl with VHCP who failed ventriculoperitoneal shunting as the sole treatment of her hydrocephalus presented with increasing ascites. She was successfully treated with ventriculoperitoneal shunting and endoscopic Bugby wire-directed monopolar contact coagulation of the hyperplastic choroid plexus. Postoperatively her head circumference and cognitive development is normal for her age, and her ascites has resolved. Endoscopic contact coagulation of the hyperplastic choroid plexus is a minimally invasive surgical method which treats the cause of the CSF production while avoiding the operative complications of open choroid plexus resection.

Visual impairment associated with mutism after posterior fossa surgery in children

OBJECTIVE

To report four children with visual impairment associated with mutism after posterior fossa surgery. Mutism after posterior fossa surgery is a well-described phenomena, but to our knowledge, visual impairment has not been reported in association with it.

METHODS

Record review of four children (age range, 3-7 yr) who underwent posterior fossa surgery (via suboccipital craniotomies) for removal of a medulloblastoma (three patients) or ependymoma (one patient). Each presented with headache, ataxia, or nausea and vomiting, but none had preoperative visual complaints other than diplopia. Postoperatively, all patients were mute, and because of apparent visual loss, neuro-ophthalmic consultation was requested. Postoperative scans and examinations were also reviewed.

RESULTS

Each child was awake but appeared withdrawn without verbal output. No child blinked to threat or fixed or followed. In each case, pupillary reactivity was normal, and funduscopic examinations revealed only papilledema. One child reached for money. Within weeks or months postoperatively, the mutism spontaneously resolved, and visual behavior in general improved, roughly in parallel. During the follow-up period, papilledema resolved and the disc color was normal in each case. Magnetic resonance images obtained postoperatively revealed nothing remarkable, except surgical defects, without lesions in the retrogeniculate pathway.

CONCLUSION

Impaired visual behavior, mimicking cortical visual loss, may be associated with mutism after posterior fossa surgery in children. The prognosis for recovery is excellent and parallels the return of normal speech. The mechanism is unclear.

Lateral meningocele syndrome: three new patients and review of the literature

One female and two male patients with multiple lateral meningoceles are presented. They do not have neurofibromatosis or Marfan syndrome and share findings with the two previously described patients with multiple lateral meningoceles. The original report by Lehman et al. [1977: J Pediatr 90:49-54] was titled "familial osteosclerosis," because osteosclerosis was present in the proposita and her mother; the patient described by Philip et al. [1995: Clin Dysmorphol 4:347-351] also had increased bone density of the skull base and the sutures. Thickened calvaria were present in one of our patients; two had a prominent metopic suture. Other shared findings include multiple lateral meningoceles, Wormian bones, malar hypoplasia, downslanted palpebral fissures, a high narrow palate, and cryptorchidism in males. In addition, our patients showed ligamentous laxity, keloid formation, hypotonia, and developmental delay. A short umbilical cord was noted in two patients. One had a hypoplastic posterior arch of the atlas and an enlarged sella, as reported by Lehman et al. [1977]. Our patients appear to have the same syndrome as previously reported. We suggest it be called "lateral meningocele syndrome," because of this unique finding.

Experimental acute subdural hematoma in infant piglets

Traumatic acute subdural hematoma is associated with high mortality in the pediatric population, yet the pathophysiology remains poorly understood. The objective of this study was to develop a pediatric model of acute subdural hematoma, and to evaluate the resultant histopathological changes in the brain. Ten 3-week-old piglets were studied. A 5-mm craniotomy was made in the right frontal skull. A small silastic tube was inserted through the underlying intact dura into the subdural space. A craniotomy was made posterior to the right coronal suture with underlying dura left intact (closed cranial window model). Injection of 5 ml autologous, nonheparinized blood was accomplished through the silastic tube. Animals were sacrificed after 72 h or 1 week. During the subdural injection, intracranial pressure rose to 62 +/- 8 mm Hg, and returned to baseline within 1 h of surgery. Mean arterial blood pressure increased transiently. Cresyl violet and hematoxylin and eosin staining demonstrated extensive areas of white matter necrosis under the hematoma after 72 h survival (n = 7). Zones of necrosis were also noted in cortex, but were less extensive than those seen in white matter. These results differ from adult rodent models in which cortex is primarily affected. This is the first reported pediatric model of traumatic acute subdural hematoma. This model can be used in future studies to investigate pharmacological or other therapies which may improve outcome after this type of injury.

Disappearing subdural hematomas in children

Subdural hematomas in infants and young children are uncommon, usually occurring from nonaccidental trauma in infants or from trauma associated with motor vehicles. We report 4 children with apparent unilateral convexity subdural hematomas, 3 of which occurred from household falls and 1 occurring from a fall out of a window. These injuries were characterized by clinical symptoms consistent with the apparent forces involved, which were relatively minor in the first three instances. The clots resolved spontaneously within the first 1-2 days after injury. Such collections are likely located at least partly within the subarachnoid space, but may mimic more clinically significant subdural hematomas. Their recognition may influence decisions regarding both surgical evacuation and the likelihood of nonaccidental injury. Clinical and radiographic features distinguishing these 'disappearing subdurals' from more typical subdural hematomas are discussed.

Endoscopic repair of traumatic CSF rhinorrhea in a pediatric patient

Cerebrospinal fluid (CSF) rhinorrhea typically results from trauma to the skull base, producing leaks through either the cribiform plate region or the sphenoid bone. Traditional approaches to the repair of such leaks include a frontal craniotomy or external ethmoidectomy. An endoscopic approach through the nose has also proven to be successful. A 7-year-old male suffered traumatic CSF rhinorrhea and development of a meningocele in the region of the cribiform plate. After demonstrating the site of the leak with fluorescein dye, the defect was repaired via a transnasal endoscopic approach. The evaluation of the child with CSF rhinorrhea, including the presenting symptoms and signs and the radiographic assessment, is presented. The variety of approaches, types of repair and post-operative care are also discussed.

Long-term outcome in infants with the shaking-impact syndrome

Nonaccidental injury accounts for nearly one quarter of all hospital admissions for head injury in infancy, and is associated with significant morbidity and mortality. Long-term outcome in survivors, however, has been incompletely studied. In this series, 84 infants 2 years of age and younger with the shaking-impact syndrome consecutively admitted to a single hospital between 1978 and 1988 were identified. A questionnaire detailing current medical, developmental, and behavioral status was developed, and attempts were made to locate the 62 children surviving the acute injury. Family instability and strict confidentiality restrictions precluded locating the majority of children, but 14 children with demographic and injury characteristics similar to those of the overall group were contacted at an average of 9 years after injury. Seven children were severely disabled or vegetative, 2 were moderately disabled, and 5 had a good outcome. Of the latter group, 3 had repeated grades and/or required tutoring. Acute factors associated with poor outcome included unresponsiveness on admission, need for intubation, age less than 6 months, and bilateral or unilateral diffuse hypodensity on CT scan. All children with bilateral diffuse hypodensity and loss of gray-white differentiation on CT scan remained blind, retarded, nonverbal, and nonambulatory in spite of aggressive medical and surgical management. This study suggests that the majority of children surviving the shaking-impact syndrome suffer major permanent morbidity, and that acute factors predicting long-term outcome may help guide aggressiveness of care.

Gangliogliomas involving the optic chiasm

We report three patients with gangliogliomas involving the optic chiasm via distinct mechanisms. The ganglioglioma in one patient likely originated in the temporal lobe and spread medially to involve the chiasm, and diffuse spinal cord dissemination also occurred. Chiasmal involvement in this manner and dissemination at presentation are unusual for gangliogliomas. The tumor in a second patient was intrinsic to the hypothalmus and chiasm, while in the third patient, it involved both optic tracts, and a cyst compressed the chiasm laterally. Two patients developed severe bilateral visual loss, while the other had a stable bitemporal hemianopsia. Two patients received radiotherapy, but one continued to lose vision. Although gangliogliomas rarely involve chiasm, the mechanisms by which they produce chiasmal visual loss may be diverse, and the long-term visual prognosis is variable.

Neuroprotection by dextromethorphan in acute experimental subdural hematoma in the rat

Experimental acute subdural hematoma in the rat has been shown to produce a zone of apparent infarction under the clot, and excitatory amino acid toxicity appears to play a role in the damage observed. We report the effect of dextromethorphan, a commonly used antitussive and a noncompetitive NMDA-type glutamate receptor antagonist, on the volume of histologic damage seen at 72 h after acute subdural hematoma in the rat. Sixty-five Long-Evans rats underwent placement of acute subdural hematoma using the "cranial window" model. Fourteen animals received oral dextromethorphan, 10 mg/kg/dose, twice daily for 3 days, and an additional 20 animals also received a single 20 mg/kg intraperitoneal dose 15 min after clot placement in addition to the oral regimen. Control animals received equal volumes of sterile water. Brain lesions in all animals were characterized by well-circumscribed infarctions underlying the subdural hematoma. Lesion volume in control animals was 88.3 +/- 9.3 mm3 (mean +/- standard error of the mean), while animals receiving dextromethorphan had significantly smaller lesions, which was independent of dosing schedule (59.9 +/- 9.2 mm3)(p = 0.0403). Animal weight was also found to be a significant covariate (p = 0.038). Because of its safety in humans and efficacy as a neuroprotectant in a variety of models, dextromethorphan may be a promising agent for clinical use, particularly in children.

Hypertonic saline improves brain resuscitation in a pediatric model of head injury and hemorrhagic shock

INTRODUCTION

Brain injury accompanied by hypovolemic shock is a frequent cause of death in multiply injured children. Hypertonic saline (HTS) has been shown to return hemodynamics to normal in adult models, without increasing intracranial pressure (ICP) as seen with crystalloids. To assess fluid resuscitation, the authors evaluated HTS versus lactated Ringer's solution (LR) with respect to hemodynamics and cerebrovascular hemoglobin oxygen saturation (Sco2) in anesthetized, head-injured, 1-month-old piglets.

METHODS

Group 1 (n = 6) was studied for 3.5 hours after a cryogenic brain injury and no shock. Groups 2 and 3 had cryogenic brain injury followed by hemorrhagic shock, in which mean arterial pressure (MAP) was reduced to 40 to 50 mm Hg and maintained for 30 minutes. Group 2 (n = 5) was then resuscitated with 1 mL of 7.5% HTS per 1 mL of blood loss. Group 3 (n = 6) was resuscitated with 3 mL of LR per 1 mL of blood loss. Sco2 was determined by near-infrared spectroscopy in the injured region of the brain. All data were analyzed using analysis of variance with repeated measures.

RESULTS

MAP, ICP, temperature, serum sodium, and cardiac output (CO) were similar in all groups during baseline and between groups 2 and 3 during shock. After resuscitation, MAP, CO, and core temperature were similar in all three groups, and serum sodium was increased in the HTS group (by 29%). Sco2 increased transiently after cryogenic injury in all groups, then gradually decreased to below baseline. After shock, Sco2 decreased precipitously in group 2 and 3. After resuscitation, Sco2 was different in the two resuscitation groups, increasing in the HTS group, above baseline values, but remaining below baseline values in the LR group (P < .002). ICP was lowered by HTS resuscitation and increased by LR resuscitation (P < .002)

CONCLUSION

In our model of head injury and shock, resuscitation with either HTS or LR restored MAP and CO to control levels. However, during shock, the injured brain was severely deoxygenated, and administration of HTS restored cerebral oxygenation whereas LR did not, reflecting improved cerebral resuscitation by HTS without elevating ICP. The data suggest that HTS is a better resuscitation fluid than LR in head-injured children with hemorrhagic shock.

Crush injuries to the head in children

Although the majority of head injuries in children and adults involve dynamic loading conditions, some patients suffer static loading. Static loading occurs when forces are applied slowly to the head, and it produces a much different pattern of injuries. Crush injuries are usually described in the context of industrial accidents, but in our experience, these injuries are not rare in children. We report a series of seven crush injuries in young children admitted during a period of 29 months and describe our experience in the evaluation and treatment of this complex entity. Patient ages ranged from 15 months to 6 years. In four cases, the child's head was run over by a motor vehicle backing up in a driveway or parking lot. In the three other patients, the static loading occurred when the child climbed or pulled on a heavy object, which then fell over with the child and landed on the child's head. One child with cervicomedullary disruption died shortly after his arrival at the hospital. The others showed varying degrees of soft tissue injury to the face and scalp, with Glasgow Coma Scale scores ranging from 7 to 15. Computed tomograms and magnetic resonance images showed multiple and often extensive comminuted calvarial fractures, as well as subarachnoid and parenchymal hemorrhages. All patients had basilar cranial fractures. There was one cervical spine injury but no major vascular injuries. One child had pituitary transection, four had cranial nerve palsies, and another developed a delayed cerebrospinal fluid rhinorrhea 18 months after injury. All children made good cognitive recoveries, with some having relatively mild fixed focal deficits.(ABSTRACT TRUNCATED AT 250 WORDS)

Tissue lactate in pediatric head trauma: a clinical study using 1H NMR spectroscopy

In order to define the metabolic abnormalities associated with different types of pediatric head injury, proton magnetic resonance spectroscopy was performed on 21 cerebral regions obtained from 17 patients. On the basis of MRI scans, the regions of interest were classified as normal (6 hemispheres), or showing diffuse axonal injury (3 hemispheres), contusion (4 hemispheres), or cerebral infarction (8 hemispheres). In comparison with normal brain there was no significant elevation in tissue lactate in the diffuse axonal injury patients, but a significant increase in the regions of contusion and infarction. It is concluded that treatment strategies using buffering agents are most likely to benefit these two groups of patients.

Acute subdural hematoma: is the blood itself toxic?

Recently developed rodent models of acute subdural hematoma have shown an associated large area of infarction underlying the clot. Excitotoxic processes have been postulated to play an important role in the extensive cell death seen with these models. However, whether increased pressure, vasoactive effects, or toxicity of the blood itself is responsible for initiating or sustaining these processes remains unclear. To study the effect of blood itself, an opaque layer of autologous clot was placed on the widely exposed parietal cortex of 15 Long-Evans rats and left in place for 72 h. In control animals the cortical surface was exposed but no blood was placed and contact with blood products was carefully limited. These animals were compared to a group in whom blood was injected into the closed subdural space. Histologic analysis showed that the majority of the cortex in both control and experimental animals in the open cranial model group appeared normal. Scattered small, discrete hemorrhagic lesions on the cortical surface of both control and experimental animals were seen, which had the appearance of focal mechanical trauma or vessel avulsion. There was no significant difference in average volume of lesions between experimental and control animals (9.1 versus 9.7 mm3, p = 0.85). No areas of infarction or selective neuronal loss were seen. In comparison, animals in which blood was injected into the subdural space had significantly larger lesions underlying clot, averaging 133.6 mm3 in volume (p < 0.0003). Blood in prolonged contact with the cortical surface in the absence of increased pressure, ischemia, or other insult is insufficient to cause underlying infarction like that seen when a similar volume of blood is injected into the closed subdural space.

Seizure control following tumor surgery for childhood cortical low-grade gliomas

Detailed preoperative electroencephalographic (EEG) studies are now recommended for children with seizures and cortical tumors to define seizure foci prior to surgery. To develop a historical perspective for better evaluation of results from series reporting tumor removal combined with resection of seizure foci, the authors reviewed seizure outcome in 60 children with seizures and low-grade neoplasms treated consecutively since 1981 by surgical resection without concomitant EEG monitoring or electrocortical mapping. Forty-seven of the 60 tumors were totally or near-totally resected; 45 patients were seizure-free and two were significantly improved 1 year following surgery. Of the 50 children in this series with more than five seizures prior to surgery, 36 were seizure-free, two were significantly improved, and 12 were not improved. Factors associated with poor seizure control included a parietal tumor location, a partial tumor resection, and a history of seizures for more than 1 year prior to surgery. The children at highest risk for poor seizure control at 2 years had experienced seizures for more than 1 year prior to surgery and had undergone partial resection of their parietal low-grade glial tumors or gangliogliomas. In contradistinction, the best seizure control was seen in patients with totally resected low-grade gliomas or gangliogliomas who had experienced seizures for less than 1 year (concordance rates for being seizure-free ranged from 78% to 86%). Long-term seizure control remained excellent. These results suggest that seizure control can be obtained 2 years following tumor surgery in the majority of children with presumed tumors after extensive tumor resection without concomitant EEG monitoring or electrocortical mapping.

Exciting your neurons to death: can we prevent cell loss after brain injury?

During the past 10-15 years, major advances have been made in understanding the pathophysiologic events that occur following central nervous system insults. It has become clear that a variety of insults have in common their ability to initiate a complex cascade of biochemical events at the cellular level which, over time, lead to neuronal death. Because these events take time to occur, interruption of these cascades offers the hope of specific neuron-salvaging therapy, even when given after the insult, and provides a major step forward from conventional supportive care. This paper reviews these principles as they relate to traumatic brain injury, with emphasis on excitatory amino acid neurotransmitter toxicity (excitotoxicity). Preliminary results in animal experiments and in severely head-injured children are discussed.

Subependymal giant cell astrocytomas in children

Between 1977 and 1991, at the Children's Hospital of Philadelphia, 10 patients, 5-16 years of age, were diagnosed as having subependymal giant cell astrocytomas. These patients accounted for 1.4% of all pediatric brain tumors seen during that time interval. One patient received a course of radiation therapy, which was ineffective in preventing tumor growth. All underwent surgical resections with the goal being maximal tumor debulking, if not complete resection. In 6 patients this was accomplished by the frontal transventricular route and, in the more recent patients, surgery was performed using a transcallosal approach. There were 2 perioperative deaths, and 2 other patients died later of causes unrelated to tumor progression. The remaining 6 patients remain alive and stable at a mean of 6.7 years of follow-up (range 1.8-12.4). None of these patients has received additional radiation therapy. Two patients have no other evidence of tuberous sclerosis. The use of modern radiographic and surgical techniques has made the treatment of this disease safer than in the past.

Superficial siderosis of the central nervous system: magnetic resonance imaging and pathological correlation. Case report

The authors report a 32-year-old woman who had undergone repair of an occipital encephalocele in infancy and who experienced a 20-year history of progressive hearing loss and intermittent vertigo. After parturition, she developed a rapidly progressive quadriparesis and brain-stem dysfunction associated with persistent intraventricular and subarachnoid hemorrhage. Serial magnetic resonance (MR) images showed progressive deposition of hemosiderin along the surface of the brain, brain stem, and spinal cord, and enhanced thickened membranes at the site of the original encephalocele repair. Posterior fossa exploration disclosed hemorrhagic membranes, which were resected; despite removal of this tissue, the patient deteriorated and died. Postmortem examination confirmed iron-containing pigment along the meninges, cerebral hemispheres, brain stem, spinal cord, and cranial nerves accompanied by atrophy of the superficial cerebellar cortex. It is concluded that superficial siderosis may accompany encephalocele repair. This is believed to be the first report in the literature of superficial siderosis of the central nervous system to correlate in vivo MR images with autopsy results.

Traumatic brain injury in children

Head trauma is a common occurrence in childhood, and the spectrum of its consequences is broad. Depending on the severity, type, and location of the injury, outcome may range from complete recovery in children with mild injuries to severe disability in children with more serious injuries. Potential deficits are multiple and include motor, communicative, cognitive, sensory, behavioral, and emotional problems. Optimizing function in those areas is the goal of neurorehabilitation, and this may require medical, therapeutic, and educational interventions. An even more important goal is prevention, and here, too, the pediatrician can play an essential role.