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Biomedical subjects

O Melen

Publications and source records attributed to O Melen.

13 recordsLinked to original sources
PubMed1994

Ocular ischemic syndrome during carotid balloon occlusion testing.

The use of a double-lumen balloon catheter for temporary occlusion testing of the internal carotid artery permits simultaneous perfusion of the distal internal carotid artery (and ophthalmic artery) with heparinized saline. If saline is infused too rapidly, the result may be total or partial replacement of oxygenated blood within the ophthalmic artery. This replacement may produce the signs and symptoms of ocular ischemic syndrome. These include ipsilateral orbital pain and progressive uniocular visual loss. Simple technical adjustments in the performance of the occlusion test can prevent the development of this syndrome. Failure to recognize the cause of the observed visual loss may produce the false impression of a positive occlusion test or may falsely suggest that a thromboembolic complication has occurred. Awareness of the occurrence of this syndrome should prevent confusion concerning the predictive result of provocative carotid occlusion testing.

Adolescent↗
PubMed1993

Orbital malignant peripheral nerve sheath tumors. Treatment with surgical resection and radiation therapy.

A series of three patients with primary orbital malignant peripheral nerve sheath tumors (MPNST) is presented. Two of our patients who were treated with surgery and postoperative radiotherapy are free of tumor recurrence. The third patient showed a good response to radiation therapy. While surgical excision remains the mainstay of therapy, our patients demonstrate the usefulness of adjuvant radiation therapy in this condition.

Adult↗
PubMed1987

Neuro-ophthalmologic features of pituitary tumors.

The pituitary adenomas are one of the more common and prognostically favorable intracranial tumors. Because of their anatomic proximity to the anterior visual pathways, these tumors should be suspected in every patient with unexplained visual loss. The value of meticulous neuro-ophthalmic examination, especially formal perimetry, cannot be overemphasized. If findings point to optic nerve or chiasmal compression, appropriate radiologic studies should be undertaken without delay. Late diagnosis will often result in irreversible visual loss. The major cause of delay in diagnosis is frequently an inadequate examination. On the other hand, observation of recovery of vision after prompt diagnosis and treatment is a very gratifying experience in neuro-ophthalmology.

Humans↗
PubMed1985

Two common neuro-ophthalmic problems. Optic neuritis and transient visual disturbances.

Optic neuritis and transient visual disturbances are common and challenging neuro-ophthalmic problems. Optic neuritis may occur during the course of several neurologic and systemic disorders and is characterized by reversible central visual loss. In many patients, signs and symptoms of multiple sclerosis occur after an episode of optic neuritis. Although several risk factors for development of multiple sclerosis have been identified, the relationship between optic neuritis and multiple sclerosis is still controversial. Transient visual disturbances may take the form of visual loss or visual hallucinations. In many cases, the cause of transient visual loss is never found. Hallucinations of ocular origin, however, are easily diagnosed by a thorough eye examination.

Antibodies, Viral↗
PubMed1983

Multifocal central nervous system damage caused by toluene abuse.

Four toluene abusers had evidence of severe multifocal central nervous system damage. Impairment of cognitive, cerebellar, brainstem, auditory, and pyramidal tract function, as well as CT evidence of cerebral cortical, cerebellar, and brainstem atrophy, have been noted. In addition, we found opsoclonus, ocular flutter, and ocular dysmetria. All three patients tested had abnormal brainstem auditory evoked potentials, indicative of brainstem dysfunction. The patient with opsoclonus had CT evidence of brainstem, cerebellar, and cerebral cortical atrophy.

Adolescent↗
PubMed1981

Anomalous origin of the ophthalmic artery in a patient with amaurosis fugax.

Ectopic origin of the ophthalmic artery from the middle meningeal artery was found in a patient with amaurosis fugax. The origin of the external carotid artery on the symptomatic side was markedly stenotic. The patient's symptoms disappeared after external carotid endarterectomy. We review the ectopic sites of the ophthalmic artery and discuss atheromatous disease of the external carotid system as a cause of transient ischemic attacks.

Arteriosclerosis↗
PubMed1978

Visual disturbances in migraine.

Abnormal visual sensations are the most common and characteristic features of migraine. In some patients, they are the only features. The major visual disturbance associated with migraine is scotoma; less common are distortions in size, shape, and color of viewed objects; photophobia; and diplopia and polyopia. Sudden loss of vision occurs in retinal migraine, and paralysis, usually of the third nerve, in ophthalmoplegic migraine. Paresis also may be found with cluster headache.

Adult↗
PubMed1975

Bitemporal visual field defects in presumed multiple sclerosis.

Three patients with presumed multiple sclerosis had bitemporal hemianopia mimicking that caused by parasellar tumors; the visual loss was probably due to a plaque within the chiasm. The diagnosis of multiple sclerosis was made on the basis of a history of relapse and remission, signs and symptoms indicating involvement of different levels of the central nervous system, and normal neuroradiological studies. Extensive neuroradiological studies may be delayed or omitted in patients with established multiple sclerosis and nonprogressive bitemporal visual field defects if central visual acuity is not greatly reduced.

Adolescent↗