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Biomedical subjects

R W Beck

Publications and source records attributed to R W Beck.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1986

Sustained increases in intraocular pressure during strabismus surgery.

We measured intraoperative intraocular pressure in nine eyes of six patients, 34 to 55 years old, undergoing rectus muscle recession or resections and found sustained intraocular pressures of 77 to 84 mm Hg in the five eyes (three patients) affected by thyroid ophthalmopathy. Smaller increases were noted in the four eyes without muscle restrictions.

Adult↗
PubMed1986

Oculomasticatory myorhythmia: a unique movement disorder occurring in Whipple's disease.

We describe two patients and a previously reported patient who acquired unique pendular vergence oscillations of the eyes and concurrent contractions of the masticatory muscles, i.e., oculomasticatory myorhythmia (OMM). The smooth disjunctive eye movements cycled with a frequency of 0.8 to 1.2 Hz. An analysis of peak velocities (15 to 200 degrees/sec) with respect to peak amplitudes (5 to 25 degrees) revealed dynamics characteristic of normal vergence movements. The pathological alterations resulting in pendular vergence oscillations implicate a separately functioning, physiologically normal vergence system within the brainstem. In addition to paralysis of vertical gaze, each patient also experienced progressive somnolence and intellectual deterioration. An intestinal biopsy in 1 patient established a diagnosis of Whipple's disease, which led to appropriate treatment and amelioration of the OMM. A pathological diagnosis of Whipple's disease of the central nervous system was made in the other 2 patients; results of an intestinal biopsy in one of these patients were normal. No patient had palatal myoclonus, and olivary pseudohypertrophy was not found in two autopsy examinations. Thus, OMM is a distinct movement disorder and has been recognized only in Whipple's disease. We conclude that patients with OMM should be treated presumptively for Whipple's disease of the central nervous system, even if a jejunal biopsy is normal.

Eye Movements↗
PubMed1986

Bilateral optic nerve sheath enlargement.

A 43-year-old man presented with progressive visual loss in each eye associated with bilateral optic nerve sheath enlargement. At surgery, the left optic nerve sheath was diffusely distended with clear fluid, but biopsy of the optic nerve and its sheath revealed only normal structures. Decompression of the right optic nerve prevented further deterioration of vision in this eye. The etiology of this condition and pathogenesis of visual loss is unknown.

Adult↗
PubMed1985

Decreased visual acuity from optic disc drusen.

Although visual field defects occur commonly from optic disc drusen, reduction in visual acuity is rare. We describe four patients with reduced visual acuity and one with visual field constriction to the point of legal blindness that resulted from optic disc drusen. The acute episodic and stepwise nature of visual loss in some of the cases in our series suggests a vascular mechanism. Reduced visual acuity from drusen remains a diagnosis of exclusion. It should be considered, however, when visual loss has been acute and nonprogressive or stepwise in a nerve fiber bundle distribution and when visual acuity is not reduced until visual field constriction is severe.

Acute Disease↗
PubMed1985

Is there a racial difference in physiologic cup size?

Although many clinicians believe that there is a racial difference in the size of the physiologic cup, this premise has not been studied. To evaluate this, we prospectively examined 100 black and 100 white volunteers. Stereoscopic optic disc photographs taken of each subject were masked to block out the fundus pigmentation, randomized, and then evaluated by an experienced clinician. The average cup/disc ratio in blacks (0.35) was significantly greater (P less than 0.0001) than that in whites (0.24) for both right and left eyes. Forty percent of the optic discs of blacks and 14% of the optic discs of whites had a cup/disc ratio greater than or equal to 0.4.

Adult↗
PubMed1985

A clinical comparison of visual field testing with a new automated perimeter, the Humphrey Field Analyzer, and the Goldmann perimeter.

Automated threshold static perimetry with the Humphrey field analyzer and kinetic and suprathreshold static perimetry with the Goldmann perimeter were performed on 171 eyes: 69 with glaucoma or ocular hypertension, 69 with "neurologic" disorders, and 33 normal. The two fields were similar or differed only slightly in 78% of eyes overall and in 88% when both fields appeared reliable. In general, defects were slightly more extensive using the Humphrey than the Goldmann perimeter. In 21% of the eyes with glaucoma or ocular hypertension, defects were found with the Humphrey perimeter that were not present with the Goldmann perimeter. Patient fixation was more difficult to maintain on the Humphrey than Goldmann perimeter. Poor fixation accounted for 9% of the automated fields being inadequate whereas only 2% of the manual fields were inadequate. The results indicate that the Humphrey Field Analyzer is capable of reliably detecting and quantitating visual field defects.

Adolescent↗
PubMed1985

The phakomatoses.

Explore the source record for details and available documents.

Angiomatosis↗
PubMed1985

Post-decompression optic neuropathy.

Blindness resulting from a decompressive craniotomy is uncommon. Five patients with intracranial tumors and papilledema who developed a bilateral optic neuropathy during an apparently uncomplicated craniotomy are presented. Symptoms of visual field loss were minimal preoperatively in four. Visual recovery in general was poor. The nerve fiber bundle pattern of visual field loss in these cases implicates the optic disc as the site of damage in this disorder. It is postulated that hypoperfusion to the prelaminar portion of the optic nerve is the underlying cause.

Adolescent↗