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Biomedical subjects

R G Weaver

Publications and source records attributed to R G Weaver.

79 records · Page 5Linked to original sources
PubMedDate not supplied

Mucoceles of the sphenoid sinus.

Mucoceles of the sphenoid sinuses are uncommon; 60 cases have been reported in the world literature to date. Signs and symptoms are caused by local expansion of the mucocele and include headache (the most common symptom), ocular field deficits, external ophthalmoplegia (particularly the sixth cranial nerve), and proptosis. Radiologic correlation in the form of plain films and polytomorgraphy is the most reliable guide in the diagnosis of sphenoid sinus disease. Therapy of these lesions is surgical, and drainage can be achieved via the external ethmoid or sublabial transseptal route. Three cases are presented: two had classical findings and the third was conspicuous by the presence of aseptic meningitis in the absence of local findings.

Adult↗
PubMedDate not supplied

Unilateral blepharoptosis with synkinetic movements of the eyelids on horizontal gaze.

A 17-year-old woman with a left congenital ptosis and an alternating esotropia is presented. During horizontal gaze to the right and left, the eyelid of the abducting eye elevated and the eyelid of the adducting eye lowered. There were no synkinetic eyelid movements with contraction of the pterygoid, sternocleidomastoid, or facial muscles. Synkinetic eyelid movements due to aberrant regeneration were unlikely due to absence of previous third nerve palsy. A supranuclear innervational abnormality is proposed to explain the clinical findings.

Abducens Nerve↗
PubMedDate not supplied

The ocular changes of incontinentia pigmenti achromians (hypomelanosis of Ito).

Incontinentia pigmenti achromians is a multisystem hereditary disorder characterized specifically by a whorled or streaked cutaneous hypopigmentation and frequently characterized by numerous neurologic, musculoskeletal, and ocular abnormalities. We present a patient with incontinentia pigmenti achromians in whom the ocular abnormalities included the commonly reported exotropia, myopia, small optic nerve, and hypopigmentation of the fundus, as well as rarely reported corneal asymmetry, pannus, and atropic irides with irregular pupillary margins. The patient also had a cataract in the right eye and a retinal detachment in the left eye.

Abnormalities, Multiple↗
PubMedDate not supplied

High-resolution diffusion-weighted MR of fresh and fixed cat spinal cords: evaluation of diffusion coefficients and anisotropy.

PURPOSE: To use high-resolution diffusion-weighted and calculated apparent diffusion coefficient (ADC) MR imaging to determine whether fixation and storage influence diffusion anisotropy in white matter tracts of cat spinal cord specimens. METHODS: Four cat cord specimens were imaged using a diffusion-weighted spin-echo sequence. Diffusion encoding was applied in the section-select axis (parallel to white matter tracts) and in the read axis (perpendicular to white matter tracts). Five sets of axial diffusion-weighted images were acquired with b values ranging from 0 to 800 s/mm2 and used to obtain calculated ADC images and to determine diffusion coefficients in different regions of the white matter tracts. RESULTS: After cord fixation, a decrease in T2 relaxation and spin density in the white matter caused the signal intensity to appear similar on diffusion-weighted images when the diffusion-probing gradient was applied along both the section-select and read axes. On the calculated ADC images, however, distinct differences in signal intensities were seen in the section-select and read axes. CONCLUSION: Although there is little difference in signal intensity in the white matter tracts on diffusion-weighted images when diffusion encoding is applied in the section-select or read axis in the fixed specimens, calculated ADC images confirm that diffusion anisotropy is maintained. Therefore, calculated ADC images may be helpful in the evaluation of fixed spinal cord specimens.

Animals↗
PubMedDate not supplied

Association between the severity of chronic lung disease and first-year outcomes of very low birth weight infants.

OBJECTIVE: The objective of this study was to determine if there is an association between the severity of chronic lung disease in very low birth weight infants (as assessed by the duration of supplemental oxygen requirements in the neonatal period) and first-year neurodevelopmental, sensory, and growth outcomes as well as duration of neonatal hospitalization and first-year hospital readmissions. STUDY DESIGN: Retrospective chart review with matched subject groups. METHODS: The subjects of this study were very low birth weight infants born between 1987 and 1991 in a 17-county perinatal region of North Carolina. Infants were categorized into one of three groups on the basis of duration of supplemental oxygen requirements. Infants who were breathing room air by 28 days were classified as having no chronic lung disease; infants who required supplemental oxygen at 28 days but not at 36 weeks postmenstrual age were classified as having mild chronic lung disease; and infants who required supplemental oxygen at 36 weeks postmenstrual age were classified as having severe chronic lung disease. Infants were matched for birth weight, sex, and race. The matched groups (n = 174) were compared with respect to the incidence of first year adverse neurodevelopmental and sensory outcomes, growth patterns, and hospital readmissions during the first year. Results were analyzed with general linear models and logistic regression analyses. RESULTS: The incidence of any adverse neurodevelopmental or sensory outcome increased as severity of chronic lung disease increased from none (3.6%) to mild (21.4%) to severe (31.6%, p < 0.001). Growth patterns were similar in infants with no and mild chronic lung disease, but infants with severe chronic lung disease were significantly lighter (p < 0.01) and shorter (p < 0.005) at 40 weeks postmenstrual age and significantly lighter at 1 year adjusted age (p < 0.05). The duration of the initial hospitalization increased with chronic lung disease severity (p < 0.001). Infants with severe chronic lung disease were readmitted to the hospital significantly more often (p < 0.005) than infants with no chronic lung disease or mild chronic lung disease. CONCLUSIONS: Very low birth weight infants who required supplemental oxygen at or beyond 28 days were at increased risk for adverse neurodevelopmental and sensory outcomes, but only those infants who continued to require supplemental oxygen at 36 weeks were at increased risk for poor growth and readmission to the hospital.

Case-Control Studies↗