Toxic metabolic disorders of myelin --ophthalmological features.
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Biomedical subjects
Publications and source records attributed to S Lessell.
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Only four cases of chaismal syndromes caused by arteriovenous malformations (AVMs) have been reported. We have examined two patients with chiasmal dysfunction caused by an AVM. In one patient, the AVM was suspected only after angiography. However, the presence of an angioma of the lip might have been a clue to the diagnosis. In the other patient, seizures and pulsating proptosis led to the correct diagnosis before angiography was performed. This patient also had episodes of transient bilateral blindness, presumably caused by postictal states or by periodic shunting with ischemia (chiasmal steal).
Malignant lymphoma with orbital presentation and associated serum paraproteinemia has seldom been reported in the literature. We report two such cases of lymphoplasmacytic type, one of which was also associated with amyloidosis. Both cases were studied with immunohistologic and one with electron microscopic techniques with results that confirmed that the neoplastic cells were producing the abnormal serum immunoglobulin.
Four patients developed orbital conjunctival cysts following enucleation. The cysts were demonstrated by ultrasonography and computerized tomography and confirmed by histopathology. They were lined by a non-keratinizing stratified squamous epithelium without goblet cells and contained fluid with mucinous strands. They were excised at eight, seven, and seven, and 25 years post-enucleation, respectively, the latter being the longest interval yet recorded. A simple classification of conjunctival cysts of the orbit is proposed and the mechanisms of the development of cysts in anophthalmic sockets are discussed. The effects of secretory rate and cyst growth are reviewed and surgical management in prevention and treatment of these lesions is outlined.
We evaluated the condition of a patient with chronic papilledema due to pseudotumor cerebri in whom a permanent, monocular, inferior, altitudinal, visual field defect suddenly developed. Clinical and fluorescein angiographic findings indicated that the loss of visual field was due to ischemic optic neuropathy. Ischemic optic neuropathy might occur in papilledema if the tissue pressure in the optic disc becomes sufficiently elevated to occlude the pressure-sensitive prelaminar arterioles.
The right optic nerves of three cynomolgus monkeys were frozen under direct visualization after a modified Kröhnlein operation. Left optic nerves were subjected to an identical procedure without freezing. Postoperatively, visual evoked responses (VERs) could not be obtained by stimulating right eyes, while electroretinograms from both eyes and VERs obtained by stimulating left eyes were normal. Extensive lesions which were found in the right optic nerves of all animals were histologically similar to those obtained by freezing in the brain.
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A patient with an amyloid tumor of the orbit was studied by computed tomographic scanning. The tumor density was 10 delta units unenhanced and 72 units enhanced.
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We examined three patients with a chiasmal syndrome due to metastasis and were able to find only two additional cases in the literature. The characteristic presentation consisted of progressive impairment of vision without headache or abnormal plain skull x-ray films in patients with weight loss or diabetes insipidus. In three of the five patients, the primary malignant neoplasm was occult when symptoms and signs of chiasmal dysfunction were seen. Four patients responded well to irradiation. The chiasm may be compromised by suprasellar extension of pituitary metastasis, by infiltration from an infundicular or hypothalamic metastasis, or by hematogenous spread of tumor.
Three adults with acquired unilateral visual impairment noticed phosphenes when they heard noises. They witnessed them only when resting in a dark or dimly illuminated room. The hallucinations persisted for days in a postkeratoplasty patient, for weeks in a patient with optic neuritis, and for months in a patient with compression of the optic nerve. The sound-induced phosphenes in these cases seemed to be a pathologic variety of hypnagogic hallucination. We theorize that under conditions of altered excitability and visual deafferentation of the brain, cells capable of responding to both visual and auditory stimuli become hyperresponsive to sounds.
We prospectively studied 60 patients with uncomplicated optic neuritis (ON) to determine the risk of subsequent multiple sclerosis (MS). All patients were followed for at least 5 years (mean, 7.1 years). Seventeen patients (28 percent) developed definite MS and four (7 percent) developed probable or possible MS. Six of the 17 patients who developed definite MS did so within the first year. Forty-five percent of the women but only 11 percent of the men developed MS. Both sexes were at highest risk if the ON occurred between the ages of 21 and 40. Fifty-one percent of patients in this age group progressed to MS, whereas the risk for others was 12 percent. There was an overall increased risk of MS with recurrent ON. The course of the MS appeared to be benign during the period of observation.
Retraction of the lower eyelid is a useful sign of disease. It is an early manifestation of weakness of the facial muscles, occurring with myopathies, myasthenia, and upper and lower motor neuron facial paresis. Rarely, lower and upper lid retraction occur without proptosis in patients with Graves disease. Lower lid retraction occurs in proptosis and varies directly with the degree of proptosis. It is also seen with senile entropion or ectropion, after eye muscle or orbital surgery, and with contraction of lid tissues. Apparent retraction results when the contralateral lower lid is pathologically elevated, as in Horner syndrome, in enophthalmos, or with vertical deviations of the eye.
Fifteen patients spontaneously developed paralysis of one superior oblique muscle, which remained unexplained after an initial evaluation. Follow-up evaluation showed that all of the patients' conditions were improved. Twelve of the patients had enjoyed spontaneous, functional recoveries within four months. Three had residual diplopia that was relieved by prisms. No patient subsequently developed evidence of any local or systemic disease that could explain the ophthalmoplegia. One patient suffered a recurrence 3 1/2 years after his first episode that lasted three months and spontaneously cleared.
Nine patients with the syndrome of juvenile diabetes mellitus and optic atrophy exemplified the wide range of manifestations of this syndrome. The disease may occur as a recessively inherited or sporadic disorder and tends to have multi-system involvement. Hearing loss, diabetes insipidus, and evidence of cerebellar or central vesitbulo-ocular dysfunction are common.