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Biomedical subjects

J J Corbett

Publications and source records attributed to J J Corbett.

At least 55 records · Page 3Linked to original sources
PubMed1987

The prevalence of simple anisocoria.

We photographed the pupils of 128 normal subjects in dim light, morning and afternoon, for five consecutive days. Fifty-two of the subjects (41%) had an anisocoria of 0.4 mm or more at one time or another during these five days, but only four (3%) had unequal pupils of 0.4 mm or more in all ten photography sessions. At any given examination, a fairly constant 19% (24 of 128) of the subjects showed this amount of anisocoria. These numbers shifted dramatically when anisocoria was defined as a pupillary inequality of greater than, or less than, 0.4 mm. The prevalence of anisocoria did not vary with the time of day, from day to day, or from week to week, nor was it influenced by the sex, age, or iris color of the subject.

Adolescent↗
PubMed1987

Further observations on cerebral or retinal ischemia in patients with right-left intracardiac shunts.

Between October 1983 and November 1986, 20 patients suspected of having a paradoxical cerebral or retinal embolism were identified. Cerebral infarction was the most common presentation. Six patients had a patent foramen ovale demonstrated by cardiac catheterization or surgery. Three patients had a newly discovered atrial septal defect, and one had an atrial septal defect that had previously been treated surgically. Results of the cardiac physical examination, chest roentgenography, and electrocardiography were unremarkable in 12 patients. Eighteen patients had a right-to-left shunt demonstrated by contrast echocardiography. Nine of these patients underwent cardiac catheterization; seven had abnormal catheterization study results: four had a patent foramen ovale and three had an atrial septal defect. Sixteen patients received medical therapy only while four underwent surgery. All patients survived the initial insult. There were no deaths or ischemic recurrences on follow-up ranging from one month to three years. We believe that contrast echocardiography can provide important diagnostic information, even in situations in which cardiac involvement is not suspected. Additional studies are needed before the optimal treatment of presumptive paradoxical cerebral embolism can be determined.

Adult↗
PubMed1987

Cranial magnetic resonance imaging in eclampsia.

Although the precise neuropathologic basis for eclamptic convulsions remains unclear, intracranial hemorrhage is frequently associated with fatal cases. Magnetic resonance imaging (MRI) is a recently developed neuroimaging technique that appears superior to other processes for defining intracranial anatomy and pathophysiology. This technique has not yet been reported in eclampsia. The authors performed serial MRIs on an eclamptic woman, with findings compatible with previously described neuropathologic changes.

Adult↗
PubMed1987

Asymmetric papilledema and visual loss in pseudotumour cerebri.

We report the case of a 26 year old obese woman who presented with intermittent headaches and blurred vision in her left eye (OS) and on clinical examination had an enlarged visual field blind spot OS with OS disc edema. After an extensive neurologic work up including two nondiagnostic lumbar punctures, a clinical diagnosis of OS anterior ischemic optic neuropathy was made. Gradual progression of visual field loss OS prompted reassessment of the diagnosis and intracranial pressure was confirmed to be markedly elevated by usage of a subarachnoid monitoring bolt, thus establishing the diagnosis of pseudotumour cerebri. An optic nerve sheath fenestration was performed OS with subsequent reversal of the progressive visual field loss.

Adult↗
PubMed1986

Resolution of saccadic palsy after treatment of brain-stem metastasis.

A 65-year-old man was unable to generate normal horizontal saccadic eye movements. Smooth pursuit of sinusoidal target motion was normal. The saccadic palsy resolved rapidly, twice, after treatment with intravenous corticosteroids. Computed tomography showed a lesion in the pons, and seven months later he was found to have metastatic adenocarcinoma.

Adenocarcinoma↗
PubMed1986

Ocular neuromyotonia. A clinical description of six patients.

We report the cases of six patients with ocular neuromyotonia, a disorder believed to result from episodic involuntary discharge of ocular motor nerves producing sustained and inappropriate contraction of their respective ocular muscles. Transient disturbances of ocular motility and diplopia result. Four patients had involvement of ocular muscles supplied by the third cranial nerve: one had presumed involvement of the superior oblique muscle, and one the lateral rectus muscle, suggesting abnormal discharge in the fourth and sixth cranial nerves, respectively. Four of six patients received prior radiation therapy for pituitary tumors, implying a possible pathogenic link. Three patients improved after treatment with membrane-stabilizing medication, suggesting that unstable membranes of injured ocular motor axons may generate spontaneous impulses, which produce involuntary sustained and inappropriate ocular muscle contraction.

Abducens Nerve↗
PubMed1986

Partial dorsal mesencephalic hemorrhages: report of three cases.

We studied three patients with spontaneous dorsal mesencephalic hemorrhages. One patient had Parinaud's syndrome with a unilateral hemorrhage confined to the rostral tectal plate. The second patient had vertical gaze palsy, skew deviation, and bilateral Horner's syndrome due to a unilateral hemorrhage that involved the superior colliculus and extended anteriorly into the midbrain tegmentum and inferiorly to the rostral dorsal pons. The third patient had a hemorrhage in the caudal tectal plate, with bilateral fourth cranial nerve palsies, unilateral Horner's syndrome, and ataxia. There was hydrocephalus due to obstruction of the aqueduct in two patients. The patients recovered, but with some degree of disability.

Adult↗
PubMed1986

Spatial contrast sensitivity in facial recognition.

Recognition and learning of complex images may depend on spatial processing characteristics of the visual system. Prosopagnosia, an impairment of visual learning and recognition of faces, might result from impaired perception in spatial channels carrying crucial information. We studied spatial contrast sensitivity (SCS) in two subjects with stable facial recognition defects. One had relative SCS reduction for high-frequency gratings but could process high frequencies in room light. The other had normal SCS. Both had intact spatial processing relative to image size. The results suggest that impairments in visual spatial channels are not necessary for the development of prosopagnosia.

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

Pupillary constriction to darkness.

Patients with congenital achromatopsia and congenital stationary night blindness have been known to show a transient pupillary constriction to darkness. We examined 50 normal subjects and 108 patients with retinal and optic nerve dysfunction to see if any had an initial pupillary constriction to darkness. We used a new infrared television apparatus. Four patients with congenital stationary night blindness, four with achromatopsia, two with bilateral optic neuritis, and one with dominant optic atrophy showed the phenomenon. In the patients who showed this unusual pupillary response to darkness it was the first observable event every time the lights were turned off. The constriction could usually be seen with a handlight, and it was similar in latency to the normal pupillary dilatation to darkness. Pupillary constriction to darkness is a clinically valuable sign that can be used in the detection of congenital retinal disease in children with poor vision.

Adolescent↗
PubMed1985

Syndrome of the paramedian thalamic arteries: clinical and neuroimaging correlation.

Two patients had sudden alteration of consciousness followed by fluctuating hypersomnia and bilateral ophthalmoplegia. Magnetic resonance imaging showed asymmetric, paramedian thalamic and midbrain lesions. The clinical and neuroimaging features are consistent with the syndrome of the paramedian thalamic arteries of the basilar communicating artery. These strokes were caused by an embolus to the rostral basilar artery originating from a fibrillating heart. Magnetic resonance imaging clearly delineates the delicate pattern of arterial involvement in mesodiencephalic junction infarctions.

Aged↗
PubMed1985

The neurologic evaluation of patients with low-tension glaucoma.

One hypothesized cause of low-tension glaucoma is chronic or intermittent ischemia of the optic nerve. Since the optic nerve and brain are both parts of the central nervous system and share a common blood supply, the authors wondered if patients with low-tension glaucoma might also have clinical or radiographic evidence of cerebral atrophy. In this study, 27 patients with low-tension glaucoma were examined using neurobehavioral testing, electroencephalography, computerized tomographic scan, neurological history, and physical examination. In only a small number of patients were these tests abnormal. However, 12 of the 27 patients gave a history of common or classic migraine. This unexpected finding raises the possibility that migraine-related ischemia might be the pathogenic mechanism in some cases of low-tension glaucoma.

Aged↗
PubMed1985

Migraine and low-tension glaucoma. A case-control study.

The authors administered a standardized headache questionnaire to 54 patients with low-tension glaucoma, 182 patients with primary open-angle glaucoma, 126 patients with ocular hypertension, and 493 normal subjects. Patients with low-tension glaucoma had headaches with or without features of migraine (unilateral headache, nausea or vomiting, or visual prodromata) more frequently than did any of the other groups. The higher prevalence of headache in low-tension glaucoma patients, who were usually elderly, was especially striking when their age was considered, since headaches are less common in elderly normal subjects than in young normal subjects. Headaches were present in 86% of elderly low-tension glaucoma patients (70 yr of age or older) but in only 64% of elderly normal subjects (P = 0.04) and only 59% of elderly ocular hypertensive patients (P = 0.02). Because migraine is an ischemic disorder, its possible association with low-tension glaucoma has etiologic and therapeutic implications.

Adolescent↗
PubMed1984

Pseudotumor cerebri and pregnancy.

Pseudotumor cerebri (PTC) is most commonly seen in obese women of reproductive age. We studied 109 women with PTC between ages 16 and 44 years. In 11, PTC started during pregnancy. Thirteen women with previous diagnosis of PTC, including two of the aforementioned 11, had an additional 17 documented pregnancies. Patients were matched by age and parity with controls. Obstetric complications occurred more frequently in the controls. Visual loss occurred with the same frequency in pregnant and nonpregnant patients. Treatment of PTC patients in pregnancy should be the same as for nonpregnant PTC patients, except that calorie restriction and diuretic use are contraindicated. Obstetric management is no different from that of normal pregnancy.

Adolescent↗