Regional brain injury on conventional and diffusion weighted MRI is associated with outcome after pediatric cardiac arrest.

BACKGROUND: To assess regional brain injury on magnetic resonance imaging (MRI) after pediatric cardiac arrest (CA) and to associate regional injury with patient outcome and effects of hypothermia therapy for neuroprotection. METHODS: We performed a retrospective chart review with prospective imaging analysis. Children between 1 week and 17 years of age who had a brain MRI in the first 2 weeks after CA without other acute brain injury between 2002 and 2008 were included. Brain MRI (1.5 T General Electric, Milwaukee, WI, USA) images were analyzed by 2 blinded neuroradiologists with adjudication; images were visually graded. Brain lobes, basal ganglia, thalamus, brain stem, and cerebellum were analyzed using T1, T2, and diffusion-weighted images (DWI). RESULTS: We examined 28 subjects with median age 1.9 years (IQR 0.4-13.0) and 19 (68 %) males. Increased intensity on T2 in the basal ganglia and restricted diffusion in the brain lobes were associated with unfavorable outcome (all P < 0.05). Therapeutic hypothermia had no effect on regional brain injury. Repeat brain MRI was infrequently performed but demonstrated evolution of lesions. CONCLUSION: Children with lesions in the basal ganglia on conventional MRI and brain lobes on DWI within the first 2 weeks after CA represent a group with increased risk of poor outcome. These findings may be important for developing neuroprotective strategies based on regional brain injury and for evaluating response to therapy in interventional clinical trials.

The intelligence of hydrocephalic children.

In a group of 78 children with hydrocephalus in the first months of life, the level and pattern of intelligence were considered in relation to various parameters and symptoms of their condition. These included demography (age, sex, handedness); early developmental status; symptoms (visual, motor, and seizure); formative pathology; type of hydrocephalus; site of CSF obstruction; extent and configuration of cortical thinning; and shunt treatment. The common outcome of early hydrocephalus is an uneven growth of intelligence during childhood, with nonverbal intelligence developing less well than verbal intelligence. The origin of this selective cognitive deficit is in neither the hydrocephalic condition itself nor its treatment, but rather in the developmental brain anomalies and symptoms to which the hydrocephalic child is prone: In children with aqueduct blocks and intraventricular hydrocephalus, a selectively thin vertex and occipital lobe; in any hydrocephalic child, ocular abnormalities, motor deficits, and seizures.

Brain tumors in children and adolescents--II. The neuroanatomy of deficits in working, associative and serial-order memory.

The neuroanatomy of memory deficits was studied in 46 children and adolescents with brain tumors. CT-scan reconstructions of 88 brain regions were coded with respect to tumor and related damage, and multiple regression procedures established patterns of brain damage predictive of memory deficits. Two forms of memory revealed non-overlapping focal neuroanatomical substrates: memory for the serial order of pictures that corresponded to heard words involved structures in the limbic system and hypothalamic-pituitary axis; whereas working memory, in which each of a succession of heard words is stored in temporary memory long enough to be compared to or contrasted with incoming words, involved the pineal-habenular region and the anterior and medial thalamic nuclei. Memory for semantically-based word-picture associations, in contrast, was unaffected by tumors in several subcortical brain regions. These data bear on current analyses of the neural substrates of associative and representational memory.

Focal ischemic cerebral injury in the newborn: diagnosis by ultrasound and correlation with computed tomographic scan.

Ischemic brain injury in the newborn is a common cause of subsequent neurologic deficits seen in older children. Clearly, determination of severity and location of such injury is important for management and prognosis. Although ultrasound scanning of the brain has been used extensively in the premature infant for diagnosis of hemorrhagic lesions, its use in the term infant for recognition of ischemic cerebral lesions has not been reported. Four cases are described in which focal echodense areas were identified on ultrasound scan of the brain. These echodense areas on ultrasound corresponded to the appearance on computed tomographic (CT) scan of areas of decreased density which are known to represent ischemic cerebral injury. In three of the four cases there were focal neurologic findings and/or focal abnormalities on EEG. In two cases, real-time ultrasound scanning demonstrated changes in arterial pulsations in cerebral vessels in the area of the lesions. Thus in both, there was diminution in pulsations within the echodense areas and in one case, an increase in pulsations was observed at the periphery of the echodense lesion. Our data demonstrate the value of ultrasound scanning for assessment of the extent and location of focal cerebral ischemic lesions in the newborn. Such assessment permits assessment of prognosis.

Radiologic characteristics of primitive neuroectodermal tumors in children.

Radiographic findings are reviewed in 31 children with primitive neural ectodermal tumors seen at the Hospital for Sick Children from 1962 through 1983. Seventeen children were initially evaluated with computed tomography (CT). Ten of these had both CT studies and angiography. The tumors were large, irregular, typically iso- to hyperdense, and showed dense, heterogeneous contrast enhancement. Cysts were present in 65% and calcifications in 71% of cases. The angiographic findings were nonspecific, ranging from avascular to markedly vascular. Although these tumors were usually found in the cerebral hemisphere, particularly the frontal lobes, two cases are included of tumors arising elsewhere: one in the pineal and one in the suprasellar region. Epidemiologic data are reviewed.

Contrast enhancement of the irradiated spinal cord in children.

Four children are reported in whom marked contrast enhancement of the spinal cord and roots was demonstrated by computed tomography months to years after relatively low dose therapeutic irradiation of paraspinal tumors, the radiation field including the cord. This phenomenon, previously unreported, probably represents subclinical radiation injury. None of the children had any neurologic abnormalities.

Iatrogenic embolization: complication of pediatric cerebral angiography.

Fourteen cases of inadvertent iatrogenic embolization of cerebral vessels occurring in a consecutive series of 3,731 angiographies in infants and children were studies. The incidence of embolization(0.9% of all patients ond 0.4% of all angiographic examinations) was about the same as has been reported in adults, but the clinical consequences were much milder, only one patient having documented transient neurologic symptoms. Also the angiographic appearance of the emboli differed from those described in adults. These differences may in part be due to the technique (general anesthesia with hyperventilation) but also to different reactions towards ischemia and to different types of emboli in children.

Evaluation of the infant spine by direct sagittal computed tomography.

Direct sagittal computed tomography (CT) and metrizamide myelography, in addition to standard axial CT, have proven most useful in evaluation of complex anomalies of the infant spine. Direct sagittal CT was performed by placing the entire infant sideways and supine within the gantry after metrizamide was injected. This technique was performed in six infants with diagnoses of lipoma with dysraphism, lipomyelomeningocele, lipomyelocystocele, lumbosacral agenesis with cord regression, capillary hemangioma, and vertebral osteomyelitis. The technique showed the relation and/or extension of lesions in the dorsal ventral plane, particularly the presence or absence of subarachnoid, enteric, or genitourinary communication. Spinal and paraspinal anatomic detail was also demonstrated beautifully.

Benign suprasellar cysts: the CT approach.

Preoperative diagnosis of intracranial cysts has been simplified and made more rapid and accurate with computed tomography (CT). By means of conventional CT and CT metrizamide ventriculography, the position and communication of intracranial cysts with the ventricular system and subarachnoid space or cisterns can be demonstrated. Suprasellar arachnoid cysts can produce significant neurologic and endocrinologic abnormalities due to their position. They are a surgically curable cause of hydrocephalus. Preoperative differentiation from aqueduct stenosis or other causes of a large third ventricle is important. The usefulness of coronal CT and CT metrizamide ventriculography in the investigation of these lesions is illustrated in six patients.

Resolving MR features in osmotic myelinolysis (central pontine and extrapontine myelinolysis).

Osmotic myelinolysis is a distinctive clinical syndrome with characteristic MR features in the central pons (central pontine myelinolysis) and in other locations (extrapontine myelinolysis). We describe the resolving MR features in an adolescent who has experienced complete neurologic recovery. Regions of involvement manifested increased T2 signal intensity. The extrapontine involvement was noted to resolve earlier with interim-increased T1-weighted signal. The mechanism for the variable appearance of increased T1 signal intensity is discussed.

CT and MR evaluation of intracranial involvement in pediatric HIV infection: a clinical-imaging correlation.

PURPOSE: To review the cranial CT and MR examinations of 29 children with perinatally transmitted HIV infection and correlate the imaging findings with clinical and pathologic data. METHODS: 28 children were examined with CT, four with MR. RESULTS: CT abnormalities were seen in 25 children studied (89%), including cerebral atrophy (25 children), basal ganglia calcification (10 children), periventricular frontal white matter calcification (four children), cerebellar calcification (one child), white matter low attenuation areas (two children), intracranial hemorrhage (three children) and cerebral infarction (one child). Intracranial calcifications were only seen in association with cerebral atrophy and were never seen prior to 1 year of age. Calcifications in the periventricular white matter or cerebellum were always associated with basal ganglia calcifications. MR abnormalities were seen in all four children studied; cerebral atrophy (four children), areas of high signal intensity in white matter (four children), loss of normal posterior pituitary high signal intensity (one child). Cerebral atrophy appeared to be a nonspecific finding that was seen in some children in the absence of neurologic signs and symptoms. All children with intracranial calcifications had developmental delay. Intracranial hemorrhage was seen in children with severe thrombocytopenia. Focal intracranial infections were unusual and neoplastic lesions were not found. CONCLUSIONS: Cerebral atrophy, basal ganglia calcifications, and focal white matter lesions were the most common abnormalities seen neuroradiologically in our series of HIV-infected children; cerebral atrophy was a nonspecific finding.

Intracranial abnormalities in infants treated with extracorporeal membrane oxygenation: update on sonographic and CT findings.

PURPOSE: To determine the frequency of intracranial lesions in infants treated with extracorporeal membrane oxygenation (ECMO), to evaluate trends in frequency during an 8-year period, and to determine which infants are at highest risk for intracranial injury. METHODS: Daily sonograms were obtained in 386 infants during treatment with ECMO. Cranial CT scans were acquired after decannulation in 286 of 322 survivors. Abnormalities were classified as major or minor and hemorrhagic or nonhemorrhagic. Results were correlated with infant demographic data. RESULTS: Intracranial abnormalities were detected in 203 (52%) of the 386 infants; 73 (19%) hemorrhagic, 86 (22%) nonhemorrhagic, and 44 (11%) combined lesions. Eighty-two lesions (21%) were classified as major. Forty-six (94%) of 49 major hemorrhages were identified at sonography. CT contributed additional information in 73% of neonates with intracranial abnormalities, of which 17 were major lesions not identified at sonography. The frequency of intracranial hemorrhage was increased in infants who were septic or premature or weighed less than 2.5 kg. An increase in time spent on ECMO bypass increased the risk for nonhemorrhagic injury. During an 8-year period, the frequency of hemorrhagic and major nonhemorrhagic lesions remained constant, whereas minor nonhemorrhagic abnormalities increased significantly. CONCLUSION: Infants treated with ECMO continue to be at high risk for cerebrovascular injury. Although daily sonograms are useful in identifying major hemorrhages, follow-up CT scans are crucial for accurate evaluation of intracranial abnormalities.

Primary intracranial choriocarcinoma: a report of two cases and a review of the literature.

Among 848 cases of primary intracranial malignancy seen during a 63-year period at a pediatric hospital, there were 2 cases of primary pineal choriocarcinoma. The clinical and laboratory findings of these 2 cases were similar to those of 33 cases of intracranial choriocarcinoma reported in the literature. In 1 patient with precocious puberty, the diagnosis was confirmed by labeling human chorionic gonadotropin (HCG) within the tumor, which had been stored for 25 years. In the other patient, who is alive and well 18 months after diagnosis, the response to cranial irradiation and intensive chemotherapy was monitored with serial measurements of serum, cerebrospinal fluid, and urinary HCG and with computed tomography. We conclude that intensive chemotherapy, radiation, and tumor resection, if feasible, offer the best chance of curing this otherwise fatal disease.

Myxopapillary ependymoma of the filum terminale and cauda equina in childhood: report of seven cases and review of the literature.

Seven of fourteen children with spinal cord ependymoma had myxopapillary tumors of the filum terminale. These tumors made up 15.9% of all primary spinal neuroectodermal tumors in children (44 cases) seen during a 62-year period (1919 to 1981). Their clinical presentation, radiological features, pathological findings, treatment, and outcome are reported. Six of the seven patients were known to be alive at the time of writing. The seventh patient was lost to follow-up after 3 years without tumor recurrence. Of 5 patients whose primary mode of treatment was operation alone. 3 had intraspinal or intracranial recurrences. Despite tumor recurrences, 2 patients were long term survivors after further operation and irradiation, whereas the third patient recently received craniospinal irradiation for intracranial tumor recurrence. The 2 patients who did not have tumor recurrence after operation alone had been followed for 3 and 7 years, respectively. Two children with subtotal tumor resection and spinal irradiation had no recurrences at 1 and 17 years, respectively. Our data suggest that this unusual subtype of spinal ependymoma is not uncommon during childhood and has a good prognosis. All patients with this tumor require prolonged follow-up for tumor recurrence after operation and irradiation.

Pituitary enlargement due to lingual thyroid gland and primary hypothyroidism.

Pituitary enlargement can occur as a result of primary hypothyroidism. We present a newborn with pituitary enlargement and congenital hypothyroidism secondary to a lingual thyroid gland. Thyroid hormone therapy caused a regression of pituitary enlargement.

The role of frameless stereotactic techniques in the treatment of pediatric CNS lesions.

The surgical management of children with deep-seated lesions within the brain and skull base or with superficial lesions within functionally important regions of the brain is often challenging. In order to optimize the functional outcome of an affected child, it is essential not only to adequately treat the offending lesion, but also to minimize injury to the surrounding brain. In this study, we examined the applicability of a video-interactive frameless stereotactic system for intraoperative localization and treatment of a variety of pediatric central nervous system problems, including craniotomy for tumor (n = 14), vascular malformation (n = 3), or cortical resection for intractable epilepsy (n = 4); ventricular puncture for shunt insertion in a patient with slit ventricles (n = 2); transoral odontoid resection (n = 1); cannulation of a brainstem syrinx (n = 1); removal of a foreign body (n = 1); and posterior craniocervical decompression (n = 1). The efficacy of the system was judged on several criteria: (1) the accuracy of the targeting achieved; (2) whether the system facilitated treatment of the lesions of interest; and (3) whether neurologic function was preserved. In general, the accuracy of the system for target localization was within 2-4 mm when rigid head fixation was employed intraoperatively. In such cases, frameless stereotactic guidance was extremely helpful in providing rapid and reliable assistance with operative planning, which facilitated the treatment of a variety of lesions in critical areas of brain with minimal neurologic morbidity. Limitations of this technology and potential solutions to these shortcomings are discussed. We conclude that the application of frameless stereotaxis for intraoperative localization represents a major advance in the treatment of a variety of intracranial processes in children by providing a means for accurately directing the approach to and removal of a targeted lesion while minimizing injury to the surrounding brain.

Craniocervical junction subarachnoid hemorrhage associated with atlanto-occipital dislocation.

STUDY DESIGN: The sensitivity of plain radiographs for diagnosing traumatic atlanto-occipital dislocation and its association with craniocervical junction subarachnoid hemorrhage was examined in a retrospective review of seven patients. OBJECTIVE: The purpose of this study was to demonstrate the frequency of nondiagnostic plain radiographs and the common association of craniocervical junction subarachnoid hemorrhage in the context of reported cases of atlanto-occipital dislocation to facilitate better recognition of this injury. The use of sagittal reconstructions of computed tomography or sagittal magnetic resonance imaging for diagnosis was evaluated. SUMMARY OF BACKGROUND DATA: Although traumatic atlanto-occipital dislocation is a common cause of motor vehicle fatalities, survival has been more common in the last 16 years. However, the diagnosis was missed on lateral cervical radiographs in 38% of children and 59% of adults; fewer than half were diagnosed subsequently with plain radiography. Moreover, the diagnosis of traumatic atlanto-occipital dislocation often was not considered, because more than half of the survivors had no neurologic abnormality or unilateral deficit. Consequently, more than one third of initially undiagnosed patients experienced neurologic deterioration due to inadequate cervical immobilization. Additional radiographic studies allowing diagnosis were prompted by the neurologic worsening. METHODS: The authors reviewed seven patients treated with traumatic atlanto-occipital dislocation during a 14-year period. Emergency department records were compared with reexamination of initial cervical radiographs to determine the success in diagnosis by means of published methods. The frequency of cranio-cervical junction subarachnoid hemorrhage on computed tomography was determined, and the use of sagittal imaging for subsequent diagnosis was evaluated. RESULTS: In the emergency department, only one patient's condition was diagnosed as atlanto-occipital dislocation. Review of the initial radiographs identified an additional four patients for whom atlanto-occipital dislocation could be diagnosed. Sagittal computed tomography reconstruction or sagittal magnetic resonance imaging identified the remaining two. All but one patient had craniocervical junction subarachnoid hemorrhage. A review of reported cases revealed a common association of craniocervical junction subarachnoid hemorrhage with traumatic atlanto-occipital dislocation but not with traumatic head injury. CONCLUSIONS: The diagnosis of traumatic atlanto-occipital dislocation is often missed in the emergency department, and current methods for evaluating the integrity of the atlanto-occipital joint on cervical radiographs fail to identify all patients with this injury. Although infratentorial subarachnoid hemorrhage is uncommon in traumatic head injury, craniocervical junction subarachnoid hemorrhage is often associated with atlanto-occipital dislocation and should raise the suspicion of severe craniocervical ligamentous injury. Sagittal computed tomography reconstructions or sagittal magnetic resonance imaging can allow for the diagnosis when plain radiography is inconclusive.

Diagnostic imaging in children with spinal disorders.

The author reviews the variety of radiological modalities that may be used to investigate spinal disease and then discusses their application in specific disease states.

Holoprosencephaly and septo-optic dysplasia.

Holoprosencephaly is a rare brain anomaly, which may be seen in liveborn neonates, although it is more common in stillbirths and abortions. It may occur alone or as part of a large number of genetic syndromes and associations. It is thought to arise early in embryogenesis (6 weeks), as the prosencephalon is separating into the two hemispheres. It is a complex anomaly with markedly varying degrees of severity. The most severe alobar form affects the entire prosencephalon. The brain shows no evidence of division into two hemispheres. The central thalami and basal ganglia remain undivided and confluent, and there is a large, dorsally located cyst connected to the large single ventricle. These infants usually die shortly after birth. The semilobar form has variable amounts of hemispheric formation with normalization occurring from dorsal to ventral. Some posterior falx, occipital, and temporal horn formation and evidence of a third ventricle are present. It is compatible with life. The lobar form has the most nearly normal appearance. It often exhibits a well-formed ventricular system, absence of the septum pellucidum, a shallow falx, abnormal connection of gray and white matter across the midline, and partially formed frontal lobes. Facial anomalies, especially hypotelorism and midline clefts, generally parallel the brain malformation in severity. Visual and olfactory symptoms plus pituitary abnormalities are often present. Septo-optic dysplasia is a related entity. It has a constellation of symptoms of hypotelorism, severe visual problems, and short stature or other pituitary symptoms. Primary imaging findings include optic nerve hypoplasia and absent septum pellucidum. Septo-optic dysplasia somewhat resembles lobar holoprosencephaly. Septo-optic dysplasia is more common than holoprosencephaly. Isolated absence of the septum pellucidum is also thought to be a mild brain anomaly.

Neuroradiology of posterior fossa tumors in children.

In the examination of posterior fossa tumors, I believe that few findings are worthy of the term diagnostic. The small multiple focal calcifications of ependymomas are probably one such event, but it occurred in only 3 of the 124 tumors in this series. The large calcifications of medulloblastoma also seem to be close to a diagnostic sign, but this is also relatively uncommon. Extension to the midbrain or cerebellopontine angle in a large solid tumor is also fairly specific for medulloblastoma. A homogeneously decreased density before intravenous contrast seems to hold up as a sign of an astrocytoma in both this series and previously reported cases. Large cysts of the type typical for astrocytoma are quite uncommon in nonastrocytomas, but they do occur. Small cysts or cysts of any size in tumors that are less than 4 cm in total diameter are nonspecific findings, as are solid or cystic tumors whose solid portions are of mixed density. The relatively tumor-specific findings of the characteristic calcifications, low density and cysts of astrocytoma, and homogeneously hyperdense medulloblastomas account for approximately half of the tumors. Most of the remaining half can be accurately diagnosed by using combinations of size, location, and more general characteristics of density and contrast enhancement.