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.

Etiology of intellectual impairment in Duchenne muscular dystrophy

The precise etiology of intellectual impairment in Duchenne muscular dystrophy (DMD) is unknown. Histopathologic and computed tomographic studies have revealed structural brain changes; however, to our knowledge, no cranial magnetic resonance imaging (MRI) studies have been performed on DMD patients to further delineate these structural changes. We prospectively studied 4 DMD patients by cranial MRI, DNA deletion analysis, clinical evaluation, and intelligence testing. There was no significant correlation between verbal intelligence scores and MRI findings, DNA deletion, or the clinical severity of the disease. These first MRI studies of DMD did not reveal any significant anatomic brain alteration, other than mild atrophy in 2 patients. We believe these results must be considered when investigating the etiology of intellectual impairment in DMD in future studies with larger patient samples.

The wedge-shaped cord terminus: a radiographic sign of caudal regression

Imaging studies from 13 patients with caudal regression were reviewed retrospectively to assess the spectrum and findings of this anomaly. Seven patients were evaluated with MR and six with myelography (supplemented with CT in three). The level of regression varied from T9 to the coccyx. Although osseous abnormalities were more readily identified and characterized by CT, MR effectively depicted the level of vertebral regression, presence of central spinal stenosis, and vertebral dysraphic anomalies. MR demonstrated a characteristic wedge-shaped (longer dorsally) cord terminus in seven of the patients. When this characteristic cord terminus is seen, imaging of the lower lumbar and sacral regions should be performed to verify the diagnosis of caudal regression. Tethered spinal cords have been described in patients with caudal regression and were seen in two of our patients. We present the first cases of individuals who have survived with absence of vertebrae above the T10 level and an unusual case of caudal regression with absent lumbar vertebrae and preserved lower sacral and coccygeal vertebrae. The syndrome of caudal regression encompasses a wide spectrum of pathology that is analyzed well by modern imaging techniques.

The surgical treatment of childhood moyamoya disease

Moyamoya disease is a progressive disorder, predominantly seen in childhood, that can cause severe permanent disability. The search for effective treatment has largely been unsuccessful in the past, but recent efforts at surgical intervention have shown promising results. The natural history of moyamoya disease, the options for treatment, and a series of patients from the Hospital for Sick Children in Toronto are reviewed. The results of surgical treatment are encouraging and the authors believe that it should be offered to all pediatric patients in the progressive stage of the disease.

The role of dural anomalies in vein of Galen aneurysms: report of six cases and review of the literature

It is proposed that the vein of Galen aneurysm represents a venous ectasia secondary to an increased flow (usually caused by a deep-seated arteriovenous shunt draining either directly into the vein of Galen aneurysm or into a tributary of the vein of Galen) associated with obstruction of a dural sinus distal to the aneurysm. The closer the venous obstruction is to the vein of Galen, the better the chances are of developing obstructive (noncommunicating) hydrocephalus and the more likely it is that the venous drainage from the rest of the brain will be unaffected. The farther the venous obstruction is from the vein of Galen aneurysm, the better the chances are of developing a communicating type of hydrocephalus. The development of cardiac failure is related to the magnitude of the arteriovenous shunt. Brain damage, seizures, and hemorrhage may be related to the retrograde venous engorgement, causing impaired drainage of the healthy brain. Careful attention should be paid to the venous drainage characteristics of the lesion because the types of dural venous obstructions and anomalies vary from case to case. The term "vein of Galen aneurysm" should be abandoned in favor of the term "vein of Galen ectasia."

Tumors and cysts

"Congenital" tumors that cause hydrocephalus early in life are large masses and can easily be detected by ultrasound. CT is better for differentiating among the diverse types of mass lesions and is performed after screening by ultrasound. In our experience, ultrasound has proved successful for visualizing all of the intracranial cysts except those in the temporal fossa. Most patients with temporal fossa cysts, however, have other symptoms and signs, such as asymmetric head and seizures that lead to further investigation and correct diagnosis despite the failure to identify the temporal cysts by ultrasound. With newer and better ultrasound equipment, the detection of temporal fossa arachnoid cysts will be improved. We believe that neurosonography should be the initial tool for investigating infants and neonates who present with large heads or abnormally rapid increase in head size.

Mania. Diagnosis, state measurement and prediction of treatment response

The phenomenology of the manic state and its response to lithium drug treatment were intensively studied as part of a larger NIMH Clinical Research Branch Collaborative Program on the Psychobiology of Depression. In view of the weaknesses in current methods for measuring the components of the manic state, a new instrument was developed, the Manic Diagnostic and Severity Scale (MADS). Its sensitivity in diagnosis and in measuring change was compared to other scales already in use. Finally baseline clinical data is presented that suggests that the presence of a "mixed" manic state is a predictor of lack of clinical response to lithium treatment.

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.

Computed tomography in Alexander's disease

Computed tomography demonstrated contrast-enhancing lesions in the periventricular frontal regions, caudate nuclei, and thalami in an infant with Alexander's disease. The distribution of the enhancing lesions corresponded to the areas in which Rosenthal fibers were most prominent. These radiological findings have not been described in other white matter diseases; thus, they may help to distinguish Alexander's disease from Canavan's disease and decrease the necessity for diagnostic brain biopsy.

Yeast inorganic pyrophosphatase substrate recognition

Monodentate Co(NH3)5PPi was determined not to be a substrate for yeast inorganic pyrophosphatase while P1,P2-bidentate Co(NH3)4PPi was turned over by the enzyme at a rate of 7.5 min-1. A kinetic analysis of the substrate activities of the P1,P2-bidentate complexes, Co(en)2PPi, Cr(NH3)4PPi, Cr(H2O)(NH3)3PPi, and Cr(H2O)2(NH3)2PPi, and Cr(H2O)4PPi was carried out in order to access the potential role of the metal-water ligands in productive binding. While substitution of the H2O ligands with NH3 ligands had a minimal affect on the Km for Mg2+, the binding affinity of the complexes decreased with an increasing NH3/H2O ligand ratio as did the turnover number of the corresponding central complexes. The Co(en)2PPi complex was hydrolyzed at a rate approximately 0.6% of that for the Co(NH3)4PPi complex. The substrate activities of beta, gamma-bidentate Co(NH3)4PPPi and alpha, beta, gamma-tridentate Co(NH3)3PPP with pyrophosphatase were also tested. While both complexes were shown to bind tightly to the Mg2+-activated enzyme neither was hydrolyzed. On the other hand, in the presence of the Zn2+-activated enzyme the tridentate complex was turned over at a rate of 0.17 min-1 while the bidentate complex remained inert to hydrolysis.

Radiology of the suprapatellar region

The gross and radiological anatomy of the suprapatellar region has been reviewed and its clinical application outlined. In most patients an accurate assessment of the presence of effusion and lipohaemarthrosis of the knee joint can be made and the possibility of excluding joint disease is discussed. In the individual patient the careful application of the radiological anatomy of this region may prevent mistakes in the localisation of various pathological processes.

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.

Intracranial neoplasms in children: the effect of computed tomography on age distribution

In a review of all children with brain neoplasms evaluated at a large pediatric center during a three-year period following the introduction of computed tomography (CT), a change was observed in the age distribution at the time of clinical presentation as compared with a previous series evaluated prior to the introduction of CT. In children under six years of age, there was a highly significant trend for earlier diagnosis; within this age group, relatively more children were diagnosed in the first two years of life. Between six and twelve years of age, there was no change in frequency of brain tumor diagnosis between the two series. Above age twelve, there was again noted a highly significant increase in detection of brain tumors in the more recent series. These differences between the two series may be attributed, at least in part, to earlier referral and diagnosis since the advent of CT, although other factors cannot be excluded as possible causes of the differences.

Aneurysms of the vein of Galen. Experience at The Hospital for Sick Children, Toronto

✓ A study of the literature published between 1937 and 1981 revealed 128 aneurysms of the vein of Galen. Their clinical course and management are reviewed. During the years 1950 to 1980, 29 patients with an aneurysm of the vein of Galen were seen at The Hospital for Sick Children. In 14 of these patients surgical obliteration of their aneurysm was attempted, and in six this proved successful.

Case report. Computed tomography of the brain in severe hypoglycaemia

Computed tomographic (CT) findings in a case of extreme hypoglycaemia induced by an overdose of chlorpropamide are described. Brain lesions tend to be preferentially localized along the boundary zones ("watersheds") between the territories of the main cerebral arteries. In our case, generalized brain damage occurred during severe hypoglycaemic coma. Neuropathological changes in this condition have been the subject of previous studies in experimental animals. Computed tomography allows follow-up studies of the human brain damaged by hypoglycaemic coma. Abnormalities revealed by CT probably represent reparative tissue reactions that indirectly reflect the extent of neuronal destruction.

CT for trauma to the base of the skull and spine in children

Five patients have been selected to demonstrate the diagnostic accuracy of CT in cases of traumatic damage to the base of the skull and spine in infants and children. Ct is superior to any other diagnostic radiological technique as bone and soft tissues are usually equally well demonstrated during one visit to the Radiology Department. Thus, CT is considered to be the primary investigative procedure of choice to evaluate trauma of the base of the skull and spine in infants and children.

The CT appearance of avulsion of the posterior vertebral apophysis. A case report

Avulsion and posterior dislocation of the posterior dislocation of the posterior part of the vertebral apophysis is a rare condition, occurring mainly in adolescence. If the avulsed part is ossified it may be diagnosed with conventional X-rays including myelography. The present case shows that CT scan with sagittal reconstruction gives exact information of the nature of the lesion as well as its extension into the spinal canal, and that CT alone is sufficient for preoperative diagnosis.

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.

Computed tomographic metrizamide myelography in syringohydromyelia

Four patients with surgically verified syringohydromyelia, including 2 with and 2 without a collapsing cord, were examined with computed tomographic metrizamide myelography (CTMM). When the cord is collapsed, or a contrast-containing cyst is observed on the scan, no further examination is necessary. If the cord is not collapsed, it is difficult to differentiate an intramedullary cyst from a tumor. Flattening of the ventral border of the cord in the supine position, coupled with an increased transverse diameter and alteration of the normally smooth, oval shape are suggestive of syringohydromyelia.

CT metrizamide myelography for intraspinal and paraspinal neoplasms in infants and children

Computed tomography (CT) metrizamide myelography is an accurate and satisfactory method for examining the spinal cord in infants and children with suspected intraspinal neoplasms. It was performed in 13 infants and children and in one adult with intra- and paraspinal neoplasms. CT metrizamide myelography in paraspinal masses provides the total geography of the mass; that is, possible intraspinal extension, as well as the paraspinal portion itself. As such, it is superior to conventional myelography.

Normal cord in infants and children examined with computed tomographic metrizamide myelography

Computed tomographic metrizamide myelography (CTMM) was performed on 25 infants and children and 2 adults with normal spinal cords. Both the cord and the cauda equina were precisely outlined. The most detailed information was obtained with a small window setting, with the image subsequently magnified and color-reversed. Hounsfield-unit measurements alone were inaccurate. Advantages of CTMM include: high accuracy in demonstrating the intrathecal contents of the spine; less need for general anesthesia; and the need for a smaller amount of water-soluble contrast material than in conventional myelography. In selected cases of intraspinal abnormality in children, CTMM is recommended.

Computed tomographic metrizamide myelography in spinal dysraphism in infants and children

Computed tomographic metrizamide myelography (CTMM) is an accurate and satisfactory method for examining the spinal cord in infants and children. Twenty-three patients with spinal dysraphism have been studied by CTMM. This method has proven more informative than conventional myelography in the evaluation of the dysraphic state.

Radionuclide demonstration of relative increased blood flow in uniappendicular secondary hypertrophic osteoarthropathy

A rare case of hypertrophic osteoarthropathy (HO) limited to one lower extremity is described in a male with a history of familial polyposis coli and bilateral aortofemoral grafts. The precise etiology remains unknown. Radiography depicted the HO, but 99m Tc-methylene diphosphonate imaging showed more extensive involvement. An intra-aortic injection of 99m Tc-macroaggregates of albumin portrayed a larger blood flow to the involved limb compared to the contralateral extremity. The major part of this increase was in bone rather than in the adjacent soft tissue.

The clival-perpendicular or modified Water's view in compound tomography

The air gap type of CT scanner with tilting gantry allows the use of head positions other than the standard semi-axial. The modified Water's or clival-perpendicular position is especially useful in the diagnosis of posterior fossa disease. The position offers a view that is approximately coronal to the clivus and tentorium. The clival-perpendicular view easily separates the supra- and infratentorial compartments. It also helps to differentiate extra- and intra-axial lesions and to locate the fourth ventricle, and it gives far better vertical orientation of posterior fossa pathology.

Congenital spinal and cord lesions in children and computed tomographic metrizamide myelography

Computed tomographic metrizamide myelography (CTMM) has developed into a highly sophisticated and accurate neuroradiologic technique in the diagnosis of childhood spinal dysrhaptic states. Of the 84 patients studied by this technique, 31 with the dysrhaphic spine also had lesions such as a tethered and low conus, diastematomyelia, or neuroenteric cysts. We believe that the exquisite pathologic anatomy obtained by CTMM obviates all neuroradiologic techniques other than a preliminary anteroposterior and lateral spinal roentgenograph.

Metrizamide ventriculography and computed tomography in infants and children

Forty-three infants and children underwent conventional or CT ventriculography after instillation of metrizamide into the ventricular system. The procedure had few complications. Anatomic detail of intraventricular obstruction was good. With CT additional physiologic information can be obtained.

Tracheal collapse following esophageal atresia repair

Expiratory collapse of the trachea was demonstrated radiographically in three infants with esophageal atresia who developed episodes of severe upper respiratory obstruction in the first few weeks of life. The abnormality is most readily seen fluoroscopically in such patients, though tracheal narrowing may be visible on an expiratory lateral chest radiography. An unusually long tracheostomy tube may be required to bypass the site of obstruction.

Observation of the use of 99mTc-phosphate imaging in peripheral bone trauma

The utility of 99mTc-phosphate imaging of fractured bones adjacent to joints soon after injury is examined. Joints usually respond to trauma by a generalized increased regional concentration of the radiopharmaceutical; but with careful attention to technique, a superimposed focal deposition due to the fractured bone can be seen. Fractures which were initially indefinite or which seemed normal at radiography were revealed as early as 7 hours after injury. In our experience, failure to show a focal concentration beyond 3 days excludes a fracture. However, a focal concentration need not necessarily represent a gross fracture; a ligamentous avulsion of a bone chip and/or periosteum could yield the same picture and not be disclosed by radiography. Radionuclide imaging of joint fractures is a useful adjunct to clinical assessment.

Mathematic models for cancer chemotherapy: pharmacokinetic and cell kinetic considerations

This paper presents a theoretic study of pharmacokinetic and cell kinetic models for cancer chemotherapeutic systems. The mathematic analysis is based on a modified procedure deduced from DeVita's scheme of the relationship between the cellular kinetics of normal and tumor tissues and the pharmacokinetics of antitumor agents for designing an optimal dose and schedule for cancer treatment. In this scheme pharmacokinetic models and cell-drug interactions at the tumor site are incorporated into the cell cycle kinetic models to form the cancer chemotherapeutic model systems. Three cell cycle kinetic models are presented under alternative hypotheses concerning the mechanism of the resting cells, while each tumor mass is comprised of cells in proliferating (consisting of the four cycle phases G1, S, G2, and M), resting (Go), and non dividing (D, dead) states. An algorithm and a computer program for simulating the tumor populations during scheduled treatments have been prepared. By a suitable selection of expressions for cell-drug interactions, the program is able to simulate tumor behavior during scheduled treatments with different classes of anticancer agent such as cell cycle phase-specific, cell cycle-specific, or cell cycle-specific, or cell cycle-nonspecific drugs. A preliminary study of the L1210-ara-C therapeutic system is included to demonstrate the computer simulation procedures.