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Biomedical subjects

M D Nelson

Publications and source records attributed to M D Nelson.

At least 55 records · Page 3Linked to original sources
PubMed1993

Orofacial abscesses of odontogenic origin in the pediatric patient. Report of two cases.

Odontogenic infections rarely spread beyond the periapical space. Occasionally spread of infection into contiguous anatomic areas occurs through bone, fascial or muscular barriers. Two cases of orofacial abscess of odontogenic origin in the pediatric patient are presented, one imaged with CT and the other with MRI. Both abscesses involved the deep and superficial tissues of the face. Additionally, one of the abscesses extended into the orbit and the other involved the preseptal soft tissue. The pathogenesis, mechanism of spread and management of the disease are discussed.

Abscess↗
PubMed1993

Prenatal WIC participation can reduce low birth weight and newborn medical costs: a cost-benefit analysis of WIC participation in North Carolina.

A number of previous studies have found that prenatal participation in the Special Supplemental Food Program for Women, Infants, and Children (WIC) improves birth outcomes, but only a few studies have provided cost-benefit analyses. The present study linked Medicaid and WIC data files to birth certificates for live births in North Carolina in 1988. Women who received Medicaid benefits and prenatal WIC services had substantially lower rates of low and very low birth weight than did women who received Medicaid but not prenatal WIC. Among white women, the rate of low birth weight was 22% lower for WIC participants and the rate of very low birth weight was 44% lower; among black women, these rates were 31% and 57% lower, respectively, for the WIC participants. Multivariate logistic regression analysis confirmed that prenatal participation in a WIC program reduced the rate of low birth weight. It was estimated that for each $1.00 spent on WIC services, Medicaid savings in costs for newborn medical care were $2.91. A higher level of WIC participation was associated with better birth outcomes and lower costs. These results indicate that prenatal WIC participation can effectively reduce low birth weight and newborn medical care costs among infants born to women in poverty.

Black or African American↗
PubMed1993

Phase III multicenter clinical investigation to determine the safety and efficacy of gadoteridol in children suspected of having neurologic disease.

A phase III open-label clinical trial was conducted at 11 institutions to determine the safety and efficacy of gadoteridol in children suspected of having neurologic disease. One hundred three children were included in the safety analysis; 92 were evaluated for efficacy (76 intracranial and 16 spinal examinations). Three adverse events were reported in two children. All adverse events were considered minor and resolved spontaneously without treatment or sequelae. In a comparison of enhanced T1-weighted magnetic resonance images with unenhanced T1- and T2-weighted images, enhancement of disease was noted in 70% of the intracranial and 38% of the spinal examinations. Additional diagnostic information was reported in 82% of the postcontrast intracranial examinations and 62% of the spinal examinations. Use of this additional information contributed to a potential modification of patient diagnosis in 48% of intracranial and 20% of spinal cases with additional information. These results indicate excellent safety and efficacy for use of gadoteridol in children with suspected intracranial or spinal disease.

Adolescent↗
PubMed1993

Effects of human immunodeficiency virus and immune status on magnetic resonance imaging of the brain in hemophilic subjects: results from the hemophilia growth and development study.

To determine the effects of hemophilia and human immunodeficiency virus (HIV) infection on the nervous system, the authors examined the relationship of brain magnetic resonance imaging (MRI) findings to immunologic function and neurologic examination findings. Baseline examinations included physical and neurologic examination, immunologic and virologic testing, and MRI of the brain. On neurologic examination, muscle atrophy was considered to be related to hemophilia if adjacent joints had arthropathy due to bleeding. Muscle atrophy was considered non-hemophilia-related if unrelated to arthropathy or if muscle atrophy was diffuse. Subjects were boys aged 6 to 19 years, enrolled in a multicenter study of the effects of hemophilia and HIV infection on growth and development, all with congenital coagulopathies requiring factor infusions. Three hundred ten subjects had complete data including neurologic examination, T-cell subsets, HIV antibodies, and MRI. Subjects with HIV infection whose CD4+ counts were < 200/microL were compared with subjects with HIV infection and CD4+ counts > or = 200/microL and with HIV-negative subjects, all of whom had CD4+ counts > 200/microL. MRI studies were normal in 230. Abnormal MRI studies were more frequent in HIV-positive subjects with CD4+ counts < 200 (29.4% abnormal compared with 17% in HIV-positive subjects with CD4+ counts > or = 200 and 15.3% in HIV-negative subjects). Diffuse atrophy accounted for most of the excess abnormalities in HIV-positive subjects with CD4+ counts < 200 (77.3% of abnormal scans). Diffuse atrophy on MRI was associated with decreased muscle bulk on neurologic examination, but not with abnormal tendon reflexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Routine use of magnetic resonance imaging in idiopathic scoliosis patients less than eleven years of age.

The purpose of this study was to determine the incidence of intraspinal pathology presenting as idiopathic scoliosis in children less than 11 years of age and otherwise neurologically normal. Twenty-six consecutive patients (5 boys, 21 girls) with idiopathic scoliosis measuring at least 15 degrees were studied with magnetic resonance imaging. Five children (19.2%) were diagnosed by magnetic resonance imaging to have Chiari-I malformations with hydromyelia (two patients), syringomelia (one patient), intramedullary tumor (one patient) and terminal lipoma (one patient). Only two of the five patients had left thoracic curves. Intramedullary spinal cord pathology can present as scoliosis without neurologic signs. Scoliosis can be the initial neurologic sign suggesting intraspinal pathology, and magnetic resonance imaging is indicated in routine evaluation of children less than 11 years of age.

Arnold-Chiari Malformation↗
PubMed1992

Galactosemia: evaluation with MR imaging.

The cerebral findings at magnetic resonance imaging in 67 transferase-deficient galactosemic patients (36 female, 31 male; median age, 10 years) are reported. Twenty-two patients had mild cerebral atrophy, eight had cerebellar atrophy, and 11 had multiple small hyperintense lesions in the cerebral white matter on T2-weighted images. The classic galactosemic patients (those without measurable transferase activity) older than 1 year of age did not show the normal dropoff in peripheral white matter signal intensity on intermediate- and T2-weighted images. The authors postulate that this abnormal signal intensity is due to altered myelin formation secondary to the inability to make sufficient and/or normal galactocerebroside.

Adolescent↗
PubMed1992

Brain abnormalities in male children and adolescents with hemophilia: detection with MR imaging. The Hemophilia Growth and Development Study Group.

Cranial magnetic resonance (MR) imaging was performed in 124 male patients (aged 7-19 years), from 14 institutions, in whom a diagnosis of moderate to severe hemophilia was made. Blood tests in all subjects were negative for human immunodeficiency virus. Findings in MR studies were abnormal in 25 (20.2%) subjects. Six lesions in five subjects were classified as congenital. The most commonly identified congenital lesion was a posterior fossa collection of cerebrospinal fluid (five cases). Twenty-two subjects had acquired lesions that were probably related to the hemophilia or its treatment. The most commonly acquired lesions were single- or multifocal areas of high signal intensity within the white matter on T2-weighted images noted in 14 (11.3%) subjects. Two subjects had large focal areas of brain atrophy, and six had some degree of diffuse cerebral cortical atrophy. Three subjects (2.4%) had hemorrhagic lesions. To the authors' knowledge, the unexpected finding of small, focal, nonhemorrhagic white matter lesions has not previously been reported.

Adolescent↗
PubMed1992

Socioeconomic status and childhood mortality in North Carolina.

Children in families eligible to receive Aid to Families with Dependent Children (AFDC) were found to have substantially higher mortality rates than non-AFDC children. The disparity seems to be greater for Whites than for non-Whites. These results suggest the presence of social class differentials in access to and use of health care and related services and facilities, in exposure to environmental risks, and in knowledge of injury control measures.

Adolescent↗
PubMed1991

Prolonged response to carboplatin in an infant with brain stem glioma.

Adults and children with brain stem gliomas have a mean survival time of 15 months after radiation therapy (XRT). Infants with this tumor present additional complexities for treatment because of possible neurotoxicity of the radiation to the developing brain. We report a 15-month-old child with biopsy-proven brain stem glioma with clinical and radiographic evidence of disease progression. She was treated with 24 monthly courses of carboplatin without radiation therapy and has had a 39+ month response. The clinical response started after 3 months and the radiographic evidence was documented at 10 months by magnetic resonance imaging. The toxicity was minimal. Longitudinal neuropsychological assessment demonstrated continued improvement at 36 months post diagnosis but with some motor functioning below expected age levels. Cervico-medullary astrocytoma in a young patient may be the appropriate clinical setting for future trials of chemotherapy without XRT.

Brain Neoplasms↗
PubMed1989

Spinal cord central echo complex: histoanatomic correlation.

Real-time sonography consistently demonstrates an echo complex centrally located in the spinal cord. This echogenic focus is currently attributed to the central canal. The authors sought the source of this central echo with ultrasound (US) and histoanatomic study of both fresh and fixed cadaver spinal cords. Correlative transverse sections of the spinal cord were stained with hematoxylin-eosin and Luxol fast blue for cells and myelin and with Holzer stain for glial fibrils. The central echo complex is produced by the interface between the myelinated ventral white commissure and the central end of the anterior median fissure. Variations in the shape of the central complex seem to reflect varying degrees of flaring of the central end of the anterior median fissure. The inconstant residual central canal and islands of residual ependymal cells are clearly not the source of the central echo complex.

Adolescent↗
PubMed1989

Sonography in newborns with cutaneous manifestations of spinal abnormalities.

High-resolution ultrasound is the screening method of choice for neonates with cutaneous signs of underlying spinal pathology. This examination does not require sedation, does not use radiation and is less expensive than computed tomography or magnetic resonance imaging. Ideally, sonograms should be obtained as soon as the cutaneous marker (sacral dimple, hairy patch, skin-covered mass) is found at the newborn examination.

Female↗
PubMed1988

Transverse sinus thrombosis in newborns: clinical and magnetic resonance imaging findings.

Neonatal transverse sinus thrombosis (TST) is considered a rare and severe sequela of birth injury. Clinical descriptions of this entity are few since most published series are postmortem studies. The advent of magnetic resonance imaging (MRI) allows recognition of TST ante mortem. We describe 4 full-term infants with distinct clinical and neuroradiological features indicative of TST, which we suggest may be relatively common, with a wide spectrum of severity, including favorable outcome.

Brain↗
PubMed1988

Anorectal malformations: evaluation of associated spinal dysraphic syndromes.

The early recognition and treatment of correctable lesions of the terminal spinal cord in patients with anorectal malformations may preserve important neurologic function. Tethered cord and intraspinal masses are detectable with the use of high-resolution ultrasonography in the neonate. Fourteen infants and children with anorectal malformations and associated spinal dysraphism have been identified in our institution over the past 7 years. Six patients had cloacal exstrophy, and eight had imperforate anus (four high and four low lesions). The spinal lesions caused symptoms in only seven children; progressive neurologic deficit in five, and urinary incontinence or retention in two others. Five asymptomatic patients with cutaneous abnormalities on the back were studied and two were discovered during scoliosis evaluation. Imaging techniques included high-resolution ultrasonography, computed tomography with and without metrizamide myelography, and magnetic resonance imaging. Spinal sonography was highly accurate in the neonatal period. The application of ultrasonography can be of great advantage in early screening of patients with anorectal malformations and, in some cases, may eliminate the need for invasive imaging techniques.

Anus, Imperforate↗
PubMed1988

The natural history of repaired myelomeningocele.

With aggressive management based on careful evaluation, children afflicted with myelomeningocele can achieve their maximum potential. Sonography, MR imaging and CT myelography all play important roles in their evaluation.

Dermoid Cyst↗