Biomedical subjects
Publications and source records attributed to J J Corbett.
Rarely, primary brain tumors may present with signs and symptoms due to diffuse multifocal leptomeningeal spread of tumor. These false localizing signs divert attention from the primary tumor, which remains relatively silent. The two patients reported here exemplify the confusing clinical pictures that may result.
We measured relative afferent pupillary defects in 105 patients with various stages of optic neuritis. We detected pupillary defects in 96% of acute unilateral cases, 92% of recovered unilateral cases 91.7% of acute cases with evidence of optic neuropathy in the other eye, and 65.8% of recovered bilateral cases. With careful testing, one can find relative afferent pupillary defects in nearly all patients with unilateral optic neuritis and in most patients with bilateral disease. A patient without a pupillary defect after apparent unilateral optic neuritis frequently has evidence of disease in the other eye when visual-evoked potentials are tested.
Cerebral and retinal ischemic events have been described in mitral valve prolapse. To determine whether platelets play a part in the pathogenesis of thromboembolism we studied 29 patients with mitral valve prolapse, including nine (group I) with thromboembolism (cerebral, retinal and deep venous), eight (group II) with transient visual obscurations and 12 (group III) with neither thromboembolism nor visual complaints, compared with 18 control patients and 38 normal subjects. Patients in groups I and II had increased platelet coagulant activities concerned with the initiation and early stages of intrinsic coagulation, and group I patients had an increased proportion of circulating platelet aggregates and platelets relatively insensitive top epinephrine in aggregation and secretion. The incidence of platelet coagulation hyperactivity in patients with mitral valve prolapse was 76% (100% in group I, 75% in group II, 58% in group III), compared with 6% in control patients. These results suggest that platelets play a role in the purported association of thromboembolism and mitral valve prolapse.
A 35-year-old woman developed upbeating nystagmus while recovering from presumed Wernicke-Korsakoff syndrome. The upbeating nystagmus changed to downbeating nystagmus with convergence. The slow-phase velocity of the downbeating nystagmus varied with the convergence effort. We believe that this unusual nystagmus pattern implies convergence input to the supranuclear centers for vertical gaze.
Congenital cavitary anomalies of the optic disc (optic pit and coloboma) are uncommon and frequently go unrecognized. Patients with these defects have a high incidence of visual loss and the abnormal appearance of the discs may be mistaken for atrophy due to acquired neurological disease. Occasionally, associated midline neurological developmental malformations will be found associated with pits, colobomas, or other dysplastic optic discs, as in one of our cases. A group of patients with optic pits and colobomas referred for neurological evaluation of visual loss are presented to remind the neurologist of the appearance of these congenital crater-like defects and of the causes of loss of vision.
A patient is described who suffered from intermittent spasms of the pupillary sphincter and ciliary muscle. Both intraocular muscles contracted several times a minute, producing sporadic darkening of vision in the affected eye. The spasms continued for eleven days, so it was possible to document them pupillographically. This curious phenomenon seems to have been the result of a transient "irritability" of the ciliary ganglion.
Twenty-one patients with lesions compromising the optic tract were reviewed. The involvement of the optic tract may be diagnosed in the presence of highly incongruous hemianopia, an afferent pupillary defect, and characteristic atrophy of the optic discs. Behr's pupil, hemianopic pupillary reaction (Wernicke's sign), and associated major neurologic deficits were encountered rarely.
A wide variety of visual sensory and ocular motor problems may occur as a direct result of enlargement of the third ventricle. Four patients are described with optic nerve dysfunction, partial third nerve palsy, proptosis, and Sylvian aqueduct syndrome all resulting from an enlarged third ventricle. The pathogenetic mechanisms are discussed.
Four patients exhibiting signs of partial aberrant oculomotor regeneration without a preceding acute third nerve palsy had meningiomas involving the cavernous sinus. Two of the patients had preceding sixth nerve palsies. We propose that slowly progressive primary aberrant oculomotor regeneration is diagnostic of intracavernous meningioma. The best diagnostic studies are orbital phlebography, carotid arteriography, and possibly computerized axial tomography.
We report two elderly patients with normal erythrocyte sedimentation rate (ESR) and biopsy-confirmed giant cell arteritis. Because of the potentially disastrous consequences of undiagnosed giant cell arteritis, early treatment based on clinical diagnostic criteria is urged despite a normal ESR.
To determine whether platelets play a part in the pathogenesis of transient cerebrovascular ischemia, we studied 22 patients with transient ischemia, 18 control patients and 38 normal subjects. Platelet aggregation and [14C]-serotonin release by ADP, epinephrine and collagen were normal in all patients, as were plasma coagulation assays, except for shortened partial thromboplastin times in the patients with transient ischemia. Platelet coagulant activities concerned with initiation and early stages of intrinsic coagulation were increased two to three times in 12 patients with transient ischemic attacks with normal serum lipids and normal in the 10 others with Type IV hyperlipoproteinemia. These results indicate an association between platelet coagulant hyperactivity and transient ischemic attacks in a group of patients with normal serum lipids.
The distinction between early papilledema and drusen of the optic disk may be made more difficult by the presence of hemorrhages. We report five patients with drusen of the optic disk and associated hemorrhages. The distinguishing characteristics of both conditions are described.
Syncope precipitated by sneezing in an adult male associated with an Arnold-Chiari type I malformation and basilar invagination presents a clinical problem in the differential diagnosis and pathological anatomy of Valsalva-related syncope. An abnormally acute clivoaxial angle, small foramen magnum, and type I Arnold-Chiari malformation appear to be a combination of features intolerant of Valsalva-induced changes in cerebral volume, brain-stem position, CSF fluid dynamics, or blood vessel relationships. Proposed mechanisms of pressure transmission to the area of intracranial pathology are discussed.
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