PubMed HealthSearch

Biomedical subjects

M Feinsod

Publications and source records attributed to M Feinsod.

12 recordsLinked to original sources

Pseudostereoscopic illusion caused by interhemispheric temporal disparity: clinical and experimental observations.

An extension of Pulfrich's pseudostereoscopic illusion to a situation without interocular disparity, ie, even under purely monocular circumstances, was clinically observed and experimentally produced. The perceived distortion of the movement of a swinging pendulum was found to depend on different combinations of interhemispheric disparity induced by selective prolongation of the conduction time from the nasal or temporal retina to the corresponding hemisphere. In patients, tumor pressure caused the slower conduction time. In normal subjects, neutral density filters covering different visual fields produced similar conduction delays under experimental conditions. Recording the visually evoked response from over each hemisphere provided an objective tool for demonstration and measurement of interhemispheric differences of retinocortical conduction times in various clinical and experimental setups.

Adult

Bilateral transverse sinus obstruction in benign intracranial hypertension due to hypervitaminosis A.

Hypervitaminosis A may be associated with benign intracranial hypertension. So far, the explanation for this phenomenon has remained obscure. A 17-year-old patient with benign intracranial hypertension, following chronic vitamin A intake of 150,000 units daily for acne vulgaris, is presented. Bilateral papilledema was present and bilateral obstruction of the transverse sinuses was demonstrated in the late venous phase of cerebral angiography. Discontinuation of vitamin A and acetazolamide treatment was followed by complete regression of the signs and symptoms of intracranial hypertension. Bilateral sinus obstruction with interference of cerebral sinus outflow is suggested as a critical factor in the pathogenesis of benign intracranial hypertension in vitamin A intoxication. Menstrual dysfunction and tetracycline therapy cannot be completely excluded as possible causative factors.

Acne Vulgaris

Nasopharyngeal tumor initially manifested as myofascial pain dysfunction syndrome.

A patient with facial pain of 1 1/2 years' duration, associated with limitation of opening of the mouth, click, and osteodegenerative changes of the temporomandibular joint, was initially thought to be suffering from a myofascial pain dysfunction syndrome. At first, the patient reacted favorably to muscle exercises and an antidepressive drug, but reduced lacrimation and the development of deafness on the affected side led to re-evaluation and a diagnosis of nasopharyngeal tumor. Biopsy confirmed the presence of an adenocarcinoma of the nasopharynx. The variability of symptoms and the diagnostic problems presented by this tumor are discussed.

Carcinoma, Adenoid Cystic

Midbrain corectopia.

Intermittent corectopia was recently observed in a patient with bilateral, rostral midbrain infarction. Results from neuropathologic examination disclosed isolated but intact Edinger-Westphal nuclei. An explanation of midbrain corectopia centered on segmental innervation of the pupil by the Edinger-Westphal nucleus. In the presence of a paralyzed dilator muscle, select, central inhibition of sphincter tone resulted in an oval and eccentric pupil.

Adult

Malignant evolution of childhood chiasmal pilocytic astrocytoma.

A 27-year-old obese mentally retarded woman showed progression of antisocial behavior with periodic somnolence 18 years after biopsy and irradiation of a large pilocytic astrocytoma of the chiasm and adjacent structures. Visual function, although impaired, had not changed during the long period of postoperative observation. Before she died, the tumor showed angiographic and histologic features of malignant glioma, but neuroradiologic and neuropathologic studies did not establish conclusively that it involved new areas of the brain. This report documents a rare case in which an irradiated childhood optic glioma underwent delayed malignant evolution.

Adult

Monitoring of visual function during parasellar surgery.

Damage to the visual system is an unfortunate complication of surgery in the area of the optic chiasm. It is now possible tomonitor the functional status of the visual system intreoperatively at regulat intervals. This is accomplished by recording the Visual Evoked Response to flashes of light from light-emitting-eiodes. These diodes are embedded in a special plastic shell which inserts under the eye lids of each eye. Since the light comes from the diodes in the plastic shell, there is no need to disturb the surgical procedure when a test run is desired. A record is obtained by averaging 100 three-per-second flashes.

Adenoma, Acidophil

Electrophysiological parameters in the evaluation of occipital apoplexy.

Visual evoked responses (VER) in four cases of occipital apoplexy supplemented perimetric diagnosis with new electrophysiologic parameters. These included diagnosis of (1) optic radiation involvement by delay in the initial VER component; (2) stirate cortical involvement by obliteration of the initial and late VER components; (3) suprastriate involvement by selective loss of the late VER components, and (4) recovery at one or more of the above levels in the visual process by follow-up examination.

Adult

Acute transient monocular disequilibrium (Halpern's syndrome).

An acute transient form of monocular disequilibrium (Halpern's syndrome) was found in two patients. Misjudgement of verticality and motion was induced by looking with one eye and was alleviated by use of the fellow eye. This symptomatology is discussed in the light of recent concepts of oculovestibulocerebellar integration.

Acute Disease