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Biomedical subjects

L E Becker

Publications and source records attributed to L E Becker.

At least 307 records · Page 17Linked to original sources
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Evaluation, surgical approach and outcome of seizure patients with gangliogliomas.

A retrospective study of 15 children with intracranial gangliogliomas and intractable seizures revealed that tumors associated with seizure were located in the temporal and frontal lobes. These patients underwent lobectomy under electrocorticography. Mesial temporal sclerosis was identified in the hippocampus of the excised temporal lobe in 7 of 13 patients with temporal lobectomies. Eleven of the 15 children were seizure-free over a mean follow-up period of 4 years. The surgical approach to gangliogliomas requires careful pre-operative evaluation, including neuroimaging and electrophysiological study to locate seizure activity. Removal of epileptogenic brain as well as the ganglioglioma is recommended to optimize seizure control.

Adolescent↗
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Quantitation of medullary astrogliosis in sudden infant death syndrome.

One of the few relatively consistent pathologic observations in sudden infant death syndrome (SIDS) is astrogliosis of the brain stem. Astrogliosis is a nonspecific reactive process and its cause in SIDS, although still uncertain, is postulated to be hypoxia-ischemia. In this study, the distribution of reactive astrocytes throughout the rostral-caudal extent of the medulla has been determined. Although astrogliosis was present throughout the length of the medulla, it reached a maximum at levels 50-75% of total length, with 0% at the pontomedullary junction. Counting every reactive astrocyte through serial sections of the medulla seems unwarranted in view of the nonspecificity of the astrocytic response. This report proposes a practical approach to the quantitation of reactive astrocytes in SIDS by examining a representative sample of medulla midway through its length.

Astrocytes↗
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Neuropathology of central respiratory dysfunction in infancy.

We studied the neuropathology of 7 infants who had primary respiratory problems unrelated to increased intracranial pressure. These infants ranged in age from newborn to 2 years. Five were male. In 2 of them the main neuropathological findings were in the brainstem with prominent neuroglial heterotopia in the subarachnoid space, and aplasia of the VI and VII cranial nerves. Two infants had abnormalities of the X and XII nerves together with neuronal heterotopia and migration failure of the inferior olivary nuclei. In 1 infant diagnosed with Ondine's curse, examination showed diffuse neuronal loss and gliosis in the medullary tegmentum. One infant had a unilateral infarction in the medulla and another showed extensive gliosis in the brainstem tegmentum along with a large infarction in the region of the anterior cerebral artery. These infants exhibited a spectrum of abnormalities including neuronal dysplasia, gliosis and hypoxic-ischemic changes. In the differential diagnosis of respiratory dysfunction in infants a rare consideration is a central etiology based on malformation of essential neuronal components of the brainstem.

Agenesis of Corpus Callosum↗
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Current management of choroid plexus carcinoma in children.

Eleven children with choroid plexus carcinoma are reviewed with respect to presentation, radiographic diagnosis, treatment and pathologic histology. These cases accumulated over a 33-year period and represent 39% of all of our choroid plexus tumors (n = 28). Characteristically, choroid plexus carcinomas are associated with a poor prognosis for long-term survival. Unfortunately, efforts at total resection are hindered in part by the extreme vascularity of the tumor which itself may be of considerable volume. We have recently treated four children who had biopsy or minimal resection of their tumor after which adjuvant chemotherapy was given. Chemotherapy is not curative but it does cause a reduction in tumor volume and, more importantly, has tended to reduce the tumor vascularity. This allows for a second stage operation which is more safely performed and typically allows for more complete tumor removal. At this point, our length of follow-up is insufficient to conclude if total removal in this manner significantly increases survival but it would seem that consistent gross total removal may be an initial step toward better overall management and prognosis in this tumor type.

Antineoplastic Combined Chemotherapy Protocols↗
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Optic pathway/hypothalamic gliomas: a dilemma in management.

Optic pathway gliomas follow an unpredictable course. Some remain static for years; others increase rapidly in size and often lead to death. This unpredictability, along with the histological similarity of these tumors, has resulted in controversy about their management. We have reviewed the results of management of all 62 patients with a diagnosis of optic pathway/hypothalamic glioma treated at The Hospital for Sick Children during the years 1976-1990. Twelve patients received no direct treatment, and 3 only a biopsy. Six patients were treated with radiotherapy alone. Eight patients received radiotherapy following a biopsy. Seventeen patients were treated by resection alone and 16 had a resection followed by radiotherapy. Eight patients received chemotherapy in addition to other therapy, and in 5 of them the chemotherapy was given as an initial therapy. Forty-eight patients are well with their visual deficits but 7 of them are receiving hormone replacement therapy. Six patients have significant neurologic deficits and 8 have died.

Brain Neoplasms↗
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Cortical dysgenesis in a variant of phenylketonuria (dihydropteridine reductase deficiency).

The neuropathology of a 2 1/2-year-old patient with dihydropteridine reductase deficiency showed diffuse demyelination throughout white matter and spongy vacuolation in the long tracts of the brain stem. These changes are characteristic neuropathologic observations in untreated phenylketonuria. In addition, extensive neuronal loss, calcification and abnormal vascular proliferation were noted in the cerebral cortex, white matter, basal ganglia, and thalamus. Golgi studies demonstrated an abnormal orientation of neurons together with abnormalities of dendrites and dendritic spines. The pathogenesis of the vascular abnormalities in this condition is unknown, although folate deficiency may be involved. The secondary deficiency of serotonin and dopamine occurring during neuronal growth and differentiation may also affect the terminal stages of neuronal maturation.

Cerebral Cortex↗
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Neuropathology in patients with congenital heart disease and Down syndrome.

This report examines the relationship between congenital heart disease (CHD) and neuropathological findings in three groups of patients: Down syndrome (45 cases), isolated CHD (296 cases), and CHD with multiple anomalies (92 cases). The increase in brain weight in Down syndrome was similar to control standards up to 1 year of age, after which it was less than normal. Among the three groups, there were differences in frequency in cyanotic CHD, history of operation, and macroscopic and microscopic brain malformations. The incidence of calcification in the brain was increased in Down syndrome. Nine children out of the total cohort had cerebrovascular abnormalities. Although CHD is frequent in Down syndrome, the cerebrovasculature is spared; only infrequent minor abnormalities of the circle of Willis were detected.

Abnormalities, Multiple↗
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Dystrophin analysis in the diagnosis of childhood muscular dystrophy: an immunohistochemical study of 75 cases.

Seventy-five consecutive pediatric muscular dystrophy (MD) cases were analyzed by dystrophin immunohistochemistry (75/75), Western blot analysis (26/75), DNA analysis (30/75), and immune electron microscopy (8/75). The patients included 64 males and 11 females and the clinical diagnoses were Duchenne MD (DMD) (41), Becker MD (BMD) (8), intermediate/outlier MD (4), female DMD (3), limb girdle or Becker (1), congenital MD (CMD) (10), Fukuyama CMD (1), facioscapulohumeral MD (FSH) (3), limb girdle MD (2), and other uncharacterized dystrophies (2). Dystrophin analysis was performed on all cases using the N- and C-terminal antidystrophin antibodies. Dystrophin analysis helped to exclude an Xp21 dystrophy in four patients. Except for two patients who showed normal staining with the N-terminal and abnormal staining with the C-terminal antibody, all DMD cases showed absent staining except for the immunoreactive revertant fibers, which were generally under 5%. A variety of staining patterns was seen in BMD, ranging from normal to abnormal (variable intensity of staining, partially stained/unstained fibers). Abnormalities were observed with the C-terminal antibody in one case of CMD and Fukuyama CMD, and normal staining was present in the other dystrophies. Immune electron microscopy confirmed absence of staining in DMD and normal membrane staining in other dystrophies. Our study underscores the importance of using antibodies with specificities to different regions of the dystrophin molecule for accurate diagnosis. As abnormal staining may be encountered in non-Xp21 dystrophies such as CMD, dystrophin staining should not be used in isolation to make a diagnosis of a dystrophinopathy.

Adolescent↗
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Sudden death in infants under one year of age.

Clinical and postmortem findings on 126 consecutive cases of sudden infant deaths occurring in Metropolitan Toronto over a 42-month period were reviewed and classified. Of these cases, 101 were diagnosed as sudden infant death syndrome (SIDS), the other 25 as due to other causes. The SIDS cases were classified into three groups: A-1 (39%), infants born at term who died between 2 weeks and 6 months of age and in whom clinical and autopsy findings were negative; A-2 (4%), same as A-1, except that the infants were born prematurely (< 36 weeks of gestation); and B (57%), infants with miscellaneous minor clinical and pathological findings not directly related to or responsible for death. The most common findings in group B were clinical and/or pathological signs of minor respiratory infection. These findings were prevalent in older SIDS infants (> 10 weeks at death), with up to 80% concordance between clinical and pathological indices of respiratory infection. Group B also included cases with minor congenital abnormalities, drug use by mother, and other miscellaneous findings. This report defines the clinicopathological features of SIDS infants and describes the spectrum of findings associated with the syndrome. It is suggested that by applying uniform criteria for definition and classification of SIDS a more reliable data base can be obtained, facilitating research into the causes and pathogenesis of SIDS.

Adult↗
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A neuropathologic analysis of neonatal deaths occurring in a single neonatal unit over a 20-year period.

This study presents an overview of 2515 consecutive autopsies performed on newborn infants who died during the first 28 days of life at The Hospital for Sick Children, Toronto, during the period 1970-89. The infants were grouped into two categories according to their gestational age, then subdivided into groups of early (0-6 days) and late (7-28 days) neonatal death. Trends in the occurrence of neuropathologic observation were documented. For each 5-year period and each gestational group, the following diagnoses were recorded: hypoxic-ischemic neuronal changes, periventricular leukomalacia, infarction, kernicterus, meningitis, and hemorrhage (subependymal, parenchymal, choroidal). Over these 20 years, our results show that death in preterm infants decreased because of a drop in the incidence of subependymal hemorrhage/intraventricular hemorrhage, kernicterus, and meningitis but increased in term infants as a result of a higher frequency of hypoxic-ischemic neuronal necrosis and choroid plexus hemorrhage.

Cerebral Hemorrhage↗
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Surgical pathology of epilepsy: a review.

This review discusses the neuropathological issues pertaining to temporal lobectomies and neocortical resections for medically refractory seizures of childhood. Most cases in our pediatric series are "lesional" and have CT/MRI abnormalities that contribute to a higher incidence of "dual pathology" lesions rather than pure mesial temporal sclerosis. Almost up to two thirds of our cases are represented by neuronal migration disorders and low grade gliomas. We have also encountered lesions that have both neoplastic and malformative foci, some of which behave more like tumors, while others defy precise classification as tumor or malformation. Our preliminary data indicate a role for cytomegalovirus in some cases of Rasmussen's encephalitis.

Adolescent↗
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Pathology of chronic herpes infection associated with seizure disorder: a report of two cases with tissue detection of herpes simplex virus 1 by the polymerase chain reaction.

Although uncommon, the association of chronic encephalitis with epilepsy is well recognized. While a viral etiology has been suspected based on the morphology, to date no virus has been successfully cultured from the brain in patients with Rasmussen's encephalitis. We describe the pathologic findings and report the detection of herpes simplex virus 1 (HSV1) in the brain in two patients who presented primarily with intractable seizures. In the first patient, an intrauterine infection was suspected as the underlying basis for the seizure disorder and the extensive cerebral calcification and gliosis. The second patient (with presumed HSV1 encephalitis at age 7 months) underwent a temporal lobectomy for medically refractory seizures at the age of 3 years and pathologic examination revealed a chronic encephalitis. While immunohistochemical, ultrastructural, and culture studies were negative for viral pathogens, molecular analysis by the polymerase chain reaction (PCR) revealed HSV1 DNA sequences in both cases. Thus our cases represent two examples of chronic encephalitis associated with a seizure disorder, where a definitive viral etiology was documented by PCR.

Calcinosis↗
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Melanotic neuroectodermal tumor of infancy: clinical, radiologic, and pathologic findings in five cases.

Five pathologically proved melanotic neuroectodermal tumors of infancy are reported. These rare neoplasms of infancy exhibit a distinct predilection for the maxillary bone. Three tumors originated in the maxilla, one in the calvaria, and one in the cerebellar vermis. Those occurring in bone did not metastasize but were locally invasive, as reflected in their radiologic appearance. Bone erosion, expansion, hyperostosis, and osteogenesis can occur in the same neoplasm and were appreciated best on CT. MR imaging showed the soft-tissue component and extent of the neoplasm better than CT did. The pathologic findings from all five cases (and one possibly related melanotic tumor of the face) revealed abundant melanin. MR imaging of two melanotic tumors showed isointense T1-weighted and slightly hyperintense T2-weighted signals. This appearance is contrary to that of most melanin-containing tumors, which exhibit enhanced T1 and T2 relaxation, and indicates that variables other than the absolute amount of melanin may determine the MR signal. Clinically, rapid neoplastic growth and excessive melanin production by the tumor cells caused facial disfigurement and visible blue black discoloration. All five melanotic neuroectodermal tumors were resected and the vermian tumor was also irradiated. Four of five children were well and free from disease 1 month to 7 years after resection. The calvarial tumor was incompletely resected and involved the underlying brain, eventually causing death. The clinical, radiologic, and pathologic features of melanotic neuroectodermal tumors of infancy are reviewed. Melanotic neuroectodermal tumors of infancy that involve bone can be diagnosed from the clinical and radiologic findings. Prompt diagnosis and surgical resection are essential for cure.

Cerebellar Neoplasms↗
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Aberrant dendritic development in the human agyric cortex: a quantitative and qualitative Golgi study of two cases.

A quantitative and qualitative Golgi comparison of the visual cortex from two agyric brains and of two age-matched controls is reported. In the camera lucida drawings, most pyramidal cells were oriented vertically to the pial surface in the external cellular layer, frequently with their apical dendrites directed toward the deep layers (inverted pyramidal neurons). The deep cellular layer contained pyramidal and polymorphic neurons normally found in the second to fourth cortical layers. In quantitative analysis of the agyric cortex of a ten-month-old patient, relative immaturity of basal dendritic arborization was apparent together with a bipolar configuration of dendritic development of the pyramidal neurons. The 3-year-old patient had a significant delay in apical dendritic arborization (shorter branch length, decreased number of dendritic intersections) compared with his age-matched normal control. The pathogenesis of the abnormal dendritic development in agyria is discussed.

Cerebral Cortex↗
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Cockayne's syndrome: report of two autopsy cases associated with neurofibrillary tangles.

Neuropathological findings in two patients with Cockayne's syndrome, a rare familial condition with mental retardation, progressive neurological deficits, progeria, and dwarfism, are described. Both patients showed extensive tigroid demyelination of the white matter and massive calcifications in the striatum, pallidum, and dentate nucleus. In one patient, neurofibrillary tangles were found in neurons in the nucleus basalis of Meynert, locus ceruleus, substantia nigra, and cerebral cortex, while in the other case only a few tangles were seen in the cerebral cortex. Electron microscopy revealed paired helical filaments. The presence of neurofibrillary tangles in Cockayne's syndrome, rarely reported previously, could suggest premature aging of the brain.

Adolescent↗
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Periaqueductal microdysplasia in children with congenital aqueductal stenosis.

The brainstems of children with aqueductal stenosis (AS) and controls were examined histologically and immunohistochemically. In the periaqueductal area of children with AS, there was astrogliosis, loss of neurons (tyrosine-hydroxylase (TH) reactivity) and decreased myelination (myelin basic protein reactivity). In locus coeruleus, there was a decreased neuronal cell density (TH-positive neurons) in those with AS. In other areas of the brainstem (medial reticular formation), there appeared to be more TH and substance P reactive neurons. These alterations (dysplasia of slight degree) in neurons were more remarkable in children with AS with other identified brain anomalies than in those with only AS, judged by specific immunocytochemical identification of neurons. The periaqueductal astrogliosis and delayed/insufficient myelination suggest secondary damage to this region.

Abnormalities, Multiple↗