Search PubMed⌕ Search

Biomedical subjects

R W Beck

Publications and source records attributed to R W Beck.

At least 19 recordsLinked to original sources
PubMed1992

A randomized, controlled trial of corticosteroids in the treatment of acute optic neuritis. The Optic Neuritis Study Group.

BACKGROUND AND METHODS: The use of corticosteroids to treat optic neuritis is controversial. At 15 clinical centers, we randomly assigned 457 patients with acute optic neuritis to receive oral prednisone (1 mg per kilogram of body weight per day) for 14 days; intravenous methylprednisolone (1 g per day) for 3 days, followed by oral prednisone (1 mg per kilogram per day) for 11 days; or oral placebo for 14 days. Visual function was assessed over a six-month follow-up period. RESULTS: Visual function recovered faster in the group receiving intravenous methylprednisolone than in the placebo group; this was particularly true for the reversal of visual-field defects (P = 0.0001). Although the differences between the groups decreased with time, at six months the group that received intravenous methylprednisolone still had slightly better visual fields (P = 0.054), contrast sensitivity (P = 0.026), and color vision (P = 0.033) but not better visual acuity (P = 0.66). The outcome in the oral-prednisone group did not differ from that in the placebo group. In addition, the rate of new episodes of optic neuritis in either eye was higher in the group receiving oral prednisone, but not the group receiving intravenous methylprednisolone, than in the placebo group (relative risk for oral prednisone vs. placebo, 1.79; 95 percent confidence interval, 1.08 to 2.95). CONCLUSIONS: Intravenous methylprednisolone followed by oral prednisone speeds the recovery of visual loss due to optic neuritis and results in slightly better vision at six months. Oral prednisone alone, as prescribed in this study, is an ineffective treatment and increases the risk of new episodes of optic neuritis.

Acute Disease↗
PubMed1992

Pattern flash visual evoked potentials in patients with homonymous hemianopia.

Visual evoked potentials from seven horizontally spaced electrodes were recorded from normal subjects and subjects with homonymous hemianopia in response to hemifield pattern flash stimulation. Stimulation produced a large early peak that was positive on the scalp contralateral to the hemifield and negative on the ipsilateral scalp. From computer fitting of the amplitudes versus electrode position, the position of the equivalent source was found to be in the contralateral hemisphere. The horizontal orientation of the dipole source was approximately tangential (parallel) to the occipital scalp surface with negative polarity toward the medial fissure. In normal subjects, visual evoked potential amplitudes at the first peak were positive on the left and negative on the right for right hemifield stimulation. Left hemifield stimulation showed the opposite results. Three patients with homonymous hemianopia showed normal visual evoked potential results from their functional hemifields and nearly flat results from their hemianopic hemifields. The normal visual evoked potentials originated in their intact cortical hemispheres.

Adult↗
PubMed1990

Caries prevalence in Head Start children, 1986-87.

Since the early 1970s, caries prevalence among school-aged children in the United States has declined. It appears that a small percentage of the children experience most of the caries increment. In addition, a large proportion of children in the US who need dental care receive it. An important factor in the amount of treatment received by children is the socioeconomic status of the family. Data on caries prevalence among preschool populations are limited. The Head Start program serves low-income families in the US and offers a unique opportunity to look at individuals who may be at greater risk of health problems and may experience less access to health services. A survey of 1,796 three- to five-year old Head Start children from low-income families was conducted in 1986-87. Caries prevalence, baby bottle tooth decay prevalence and relative need for dental care are reported for fluoridated and non fluoridated communities in California, Hawaii, and Micronesia. The data reveal scores that are higher in the sample population than in five-year-olds in national surveys and among Head Start children in previous surveys.

Child↗
PubMed1989

Atonic pupil after cataract surgery.

A dilated, atonic pupil is a recognized but unusual complication of cataract surgery. It appears to be a more common occurrence than the paucity of previously published reports would suggest. In this article, seven cases of post-cataract extraction atonic pupil are described. All patients underwent uneventful cataract extraction with posterior chamber intraocular lens (IOL) implantation. In all except one patient, there was a delay from the time of surgery to the development of the atonic pupil. Pharmacologic testing demonstrated that the site of the lesion was the iris sphincter. Possible pathogenic mechanisms are discussed.

Aged↗
PubMed1989

Bilateral idiopathic inflammation of the optic nerve sheaths. Light and electron microscopic findings.

Idiopathic perioptic neuritis is a term used to describe noninfectious inflammatory disorders of the optic nerve sheaths, the causes of which are unknown. In the following report, a 68-year-old woman with bilateral visual loss was found to have chronic inflammation with necrobiotic granulomas of her optic nerve sheaths. The patient, who had no systemic condition known to be associated with necrobiotic granuloma, lost vision from infarction of the optic nerve parenchyma and from compression due to thickened meninges. Although there are similarities between the inflammatory reaction in this case to the necrobiotic dermatoses, the pathogenesis of this condition remains obscure.

Aged↗
PubMed1989

Traumatic orbital encephalocele.

We describe a 39-year-old man in whom progressive pulsatile proptosis developed 2 days after he suffered a head injury. Computed tomography revealed an isolated blow-in fracture of the orbital roof with herniation of the left frontal lobe into the orbit. Neurosurgical intervention to repair the orbital defect led to full recovery.

Adult↗
PubMed1987

Cortical blindness: etiology, diagnosis, and prognosis.

We examined 15 patients with cortical blindness, reviewed the records of 10 others, and compared these 25 patients to those in previous studies of cortical blindness. Although cerebrovascular disease was the most common cause in our series, surgery, particularly cardiac surgery, and cerebral angiography were also major causes. Only 3 patients denied their blindness, although 4 others were unaware of their visual loss. Electroencephalograms (EEGs) were performed during the period of blindness in 20 patients and all recordings were abnormal, with absent alpha rhythm. Visual evoked potentials recorded during blindness were abnormal in 15 of 19 patients, but did not correlate with the severity of visual loss or with outcome. Bioccipital lucencies were found in computed tomographic (CT) scans of 14 patients; none of the 14 regained good vision. Recovery of vision was poor in all 8 patients who had a spontaneous stroke, but fair or good in 11 of the other 17 patients. Prognosis was best in patients under the age of 40 years, in those without a history of hypertension or diabetes mellitus, and in those without associated cognitive, language, or memory impairments. We conclude that the prognosis in cortical blindness is poor when caused by stroke; EEGs are more useful than visual evoked potentials for diagnosis; and bioccipital abnormalities shown on CT scan are associated with a poor prognosis.

Blindness↗
PubMed1987

Deficits in visual function after resolution of optic neuritis.

A study was done to systematically characterize visual function in eyes with recovered optic neuritis. Thirty-five eyes from 27 patients, all of whom had recovered at least 20/30 Snellen acuity after resolution of the neuritis, were included. Minimum recovery period was 6 months. Abnormalities were found in color vision (57%), contrast sensitivity (72%), perimetry (26%), stereoacuity (80%), light brightness (89%), pupillary reaction (89%), and optic disc appearance (77%). Eighty-five percent of patients complained of at least some subjective disturbance in vision. Subjective visual complaints correlated better with deficits in contrast sensitivity than they did with the other measures. The results of the study indicate that deficits in visual function are common after resolution of optic neuritis.

Adolescent↗
PubMed1987

Familial recurrent Bell's palsy with ocular motor palsies.

We studied a family in which the father and 7 of 10 children had episodes of Bell's palsy. Five of the eight affected family members also had ocular motor palsies. Facial nerve and blink reflex studies in four affected siblings demonstrated asymmetrically reduced amplitude of evoked responses without delayed conduction. EMG revealed signs of chronic denervation and reinnervation in all four patients; two had synkinesis. Three siblings had diabetes mellitus, but with no clinically evident polyneuropathy.

Adult↗
PubMed1987

Third nerve palsy as a presenting sign of acquired immune deficiency syndrome.

The case of a 29-year-old former parenteral drug abuser who presented with a 3rd nerve palsy and contralateral ataxia is reported. The patient was found to have a positive HLTV-III titer and acquired immune deficiency syndrome was diagnosed. Computed tomography demonstrated two ring-enhancing lesions in the brain which were presumed to be due to Toxoplasma gondii.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Sudden infant death syndrome: a literature review with chiropractic implications.

Sudden infant death syndrome is the term applied to the sudden death of an infant or young child that is unexpected by history and for which a thorough postmortem examination fails to demonstrate an adequate cause of death. It is widely believed that sudden infant death syndrome is not an expression of a single cause and effect, but rather a multifactorial phenomenon. This paper gives an overview of recent developments in sudden infant death syndrome research presenting the various hypotheses regarding sudden infant death. Functional disturbances in the brainstem and cervical spinal cord areas related to the neurophysiology of respiration may contribute to the clinical findings associated with sudden infant death syndrome. Parturitional factors, which include maternal (labor and delivery) and extrinsic factors (obstetrical procedures) have received attention. Work has also been done on the development of those neuroanatomical structures associated with respiration. It is postulated that human development progresses through stages with a critical period at 2-4 months. Immaturity of the brainstem and cervical cord is characterized, histologically, by the presence of reticular dendritic spines on the neurons as well as a proliferation of astrocytes and glial cells. Any process, whether genetic, biochemical, biomechanical or traumatic, that alters normal development of the respiratory control centers related to spinal constriction and compression following birth trauma may be contributory to sudden infant death syndrome.

Chiropractic↗
PubMed1987

Anterior ischemic optic neuropathy. IX. Cup-to-disc ratio and its role in pathogenesis.

The optic disc appearance in the normal fellow eye of 126 patients with nonarteritic anterior ischemic optic neuropathy (n-AION) was compared with the discs in 23 patients with arteritic AION (a-AION) and 122 normal subjects. The number of discs with no cup was significantly greater (P less than 0.001) and the number of discs with a large cup was significantly fewer (P less than 0.001) in the n-AION group compared to the other two groups. No significant differences were found in cup size between the a-AION and normal groups. The pathogenesis of n-AION appears to be multifactorial. There is overwhelming evidence that ischemia is the primary factor. The size of the optic disc also plays a role, probably through a compressive effect at the level of the lamina cribrosa on axons subjected to ischemia. In contrast, a-AION occurs from posterior ciliary artery occlusion and disc size is not a factor.

Adult↗