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Biomedical subjects

D G Cogan

Publications and source records attributed to D G Cogan.

At least 55 records · Page 3Linked to original sources
PubMed1981

Ocular motor signs in some metabolic diseases.

Ocular motor disturbances are described with a miscellany of metabolic disturbances. Horizontal gaze abnormalities, often simulating congenital ocular motor apraxia, characterized Gaucher's disease. Vertical gaze abnormalities, especially downgaze paralysis, characterized what is generally considered a variant of Niemann-Pick disease, or sea-blue histiocytosis, but which we prefer to call the "DAF" syndrome. A form of internuclear ophthalmoplegia but with nystagmus of the adducting eye characterized abetalipoproteinemia. epileptiform eyelid and eye movements occurred in a case of methylmalonohomocystinuria. Ocular motor abnormalities are also described with variation of olivopontocerebellar degeneration and with ataxia telangiectasia.

Adolescent↗
PubMed1980

Fundal abnormalities of Gaucher's disease.

The evidence for cherry-red maculas in Gaucher's disease is questionable, but in occasional patients, scattered white spots in and on the retina appear to be characteristic. These white spots consist of clusters of swollen histiocytes (Gaucher cells).

Adolescent↗
PubMed1980

Epileptiform ocular movements with methylmalonic aciduria and homocystinuria.

A 7 1/2-year-old girl with a rare defect in cobalamin (vitamin B12) metabolism ("cobalamin C" type) developed epileptiform ocular and eyelid movements as the major clinical manifestation of the disease. One of three other patients who have been described with congenital syndrome was similarly noted to have "fluttering" of the eyelids interpreted as epileptic discharges. The metabolic abnormality produced a defect in synthesis of cobalamin coenzymes. It is characterized biochemically by the excreation of methylmalonic acid and homocystine in the urine.

Child↗
PubMed1979

Ocular manifestations of familial high-density lipoprotein deficiency (Tangier disease).

Corneal clouding is one of the manifestations of Tangier disease, an inherited disorder in which cholesterol-rich lipids are deposited in various tissues of the body. The cause of the corneal clouding is unknown. This study documents the clinical course and conjunctival biopsy findings of a 60-year-old man who was one of the earliest patients to be recognized with Tangier disease and in whom progressive corneal clouding developed in adult life. Noteworthy in the biopsy specimens were birefringent lipid particles that were predominantly present in degenerating pericytes of the conjunctival vessels.

Arteries↗
PubMed1979

Visuospatial dysgnosia.

Spatial dysgnosia may occur in patients with various forms of brain disease, including tumors, vascular accidents, Alzheimer's disease, multiple sclerosis, and developmental aberrations. Patients with lesion in the nondominant hemisphere, particularly at the junction of the occipito-temporoparietal regions, may manifest predominantly visuospatial dysgnosia--a loss of the sense of "whereness" in the relation of himself to his environment and in the relation of objects to each other. Visuospatial disturbances caused by lesions in the dominant hemisphere may be masked by other gnostic symptoms. Patients with more extensive lesions, especially those involving similar areas in both hemispheres, may also exhibit other cognitive disturbances associated with vision.

Adolescent↗
PubMed1979

The eye movement disorders of progressive supranuclear palsy.

In addition to the gross disturbances of vertical gaze, patients with progressive supranuclear palsy may show abnormalities in the saccadic and pursuit subsystems of horizontal gaze. Saccades are slower and smaller than normal. An attempt to elicit a large amplitude saccade will often result in a series of "fractionated" saccades. Pursuit eye movements become saccadic. The quick phases of vestibular and optokinetic nystagmus are of low amplitude. In the study presented, eye movements of 13 patients were recorded clinically and by electro-oculography, and data from the two methods, compared.

Adult↗
PubMed1978

Colorimetry by a new principle.

A simple and informative method is described for determining the type and extent of color defects. The subjects' responses are registered automatically on a chromaticity diagram that is based on the newtonian model. Color defects are readily identifiable by a skewing of the normal central gray area toward the defectively perceived color. The examination permits independent variation of hue and saturation for each color and requires less than five minutes for the entire procedure. Unlike conventional color tests, the present method indicates exactly what colors are or are not seen at any level of saturation.

Adolescent↗
PubMed1977

Optic nerve compression due to aneurysmal bone cyst.

A 10-year-old boy developed loss of central vision in both eyes due to compression of the optic nerves by a mass arising from the sphenoid and ethmoid sinuses. Histopathologic examination of biopsy specimens showed a fibrous matrix composed of spindle-shaped cells interspersed with small and large channels, characteristic of an aneurysmal bons cyst. One year after partial excision of the intracranial and extracranial portions fo the lesions, vision had returned to nearly normal levels. Aneurysmal bone cysts rarely involve the orbits or other cranial bones to produce ocular signs and symptoms. However, since this lesion probably represents reactive proliferation of bony tissues, rather than neoplasia, the prognosis for vision and life is good.

Bone Cysts↗
PubMed1977

Immunosuppression and eye disease. First Vail lecture.

Several viral, fungal, and protozoal diseases of the eye are significantly associated with immunologic deficiencies. Of the viral agents, cytomegaly and herpes simplex and zoster cause a discrete necrotizing retinopathy that has the characteristics of vascular occlusion. Measles may result in a delayed retinopathy that is predominantly macular and associated with subacute progressive encephalopathy. Of the fungal agents, Candida and Aspergillus are apt to involve the eye, beginning as choroidal lesions with extension forward to involve the pigment epithelium and retina secondarily. Mucor and Cryptococcus are less common. Toxoplasmosis is the one ocular protozoal disease whose incidence is increased by immunosuppression, and, like the viral diseases, is characterized by a discrete necrotizing retinopathy and probably results from activation of dormant organisms in the retina. Autoimmunity undoubtedly plays an important role in eye disease but its ocular pathogenesis is obscure.

Adult↗
PubMed1977

Papilledema.

Explore the source record for details and available documents.

Humans↗
PubMed1977

Scleral calcifications in hyperparathyroidism: demonstration by computed tomography.

Scleral calcifications were demonstrated roentgenographically in two patients with known hyperparathyroidism and clinically normal eyes. In one of these patients, scleral calcification was evident both on plain films and with computed tomography (CT). In the second patient, a solitary plaque of calcified sclera was visible only by CT. Histopathologic examination of the eyes of a third hyperparathyroid patient who died during surgery demonstrated calcium plaques in the posterior sclera consistent with the CT appearance of the sclera in the other patients.

Adult↗