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S N Merchant

Publications and source records attributed to S N Merchant.

59 records · Page 4Linked to original sources
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Histopathology of the ears, eyes, and brain in Norrie's disease (oculoacousticocerebral degeneration).

Norrie's disease is an x-linked recessive disorder characterized by progressive oculoacousticocerebral degeneration. The light and electron microscopic changes in the temporal bones, eyes, and brain of an affected 77-year-old man who suffered from bilateral profound sensorineural hearing loss, blindness, and mental retardation are described. The inner ears showed marked atrophy of the stria vascularis, severe degeneration of hair cells and cochlear neurons, and connective tissue proliferation in the spiral ganglion, osseous spiral lamina, and walls of the membranous vestibular labyrinth. The eyes showed detached retinae, dense proliferation of fibrillary glial cells in the retina and vitreous, severe atrophy of the optic nerves, and degenerative hyalinization of blood vessels. This case is the first published report of the histopathology of the inner ear in Norrie's disease.

Aged↗
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Vestibular atelectasis.

The temporal bone collection at the Massachusetts Eye and Ear Infirmary includes specimens from several cases in which the only reasonable explanation for vertigo is collapse of the walls of the ampullae and utricle, a disorder we have termed vestibular atelectasis. The clinical histories and temporal bone studies support the existence of a primary type that may have a paroxysmal or insidious onset, and a secondary type that occurs in association with other inner ear disorders. The principal clinical symptom is chronic unsteadiness, precipitated or aggravated by head movement, and sometimes associated with short episodes of spinning vertigo. It is presumed that the collapsed membranes interfere with the motion mechanics of the cupulae and otolithic membranes.

Adult↗
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Adult-onset xeroderma pigmentosum neurological disease--observations in an autopsy case.

Xeroderma pigmentosum (XP) is an inherited disease with defective DNA repair. Patients develop skin cancer because of unrepaired DNA damage produced by the ultraviolet radiation (UV) in sunlight. Many XP children also develop XP neurological disease (ND), consisting of sensorineural hearing loss (SNHL) and a primary neuronal degeneration of the central and peripheral nervous systems. Since the harmful UV in sunlight cannot reach the nervous system, the cause of the death of XP neurons has been hypothesized to result from the inability to repair their DNA that has been damaged by endogenous metabolites. Progressive XP ND originating in an adult has been identified in only a single case. Although clinically asymptomatic at the age of 47 years, the patient had audiometric evidence of a developing mild SNHL together with elicited signs and electrophysiologic evidence of a peripheral neuropathy. She died of metastatic endocervical adenocarcinoma at 49 years of age. We describe here the neuropathological findings in this patient, including examination of the inner ear. Despite clinical evidence of SNHL, there were no anatomic abnormalities of the inner ear. However, the dorsal root ganglia (DRG) showed ongoing neuronal loss. Our findings indicate that XP ND originating in this adult is, like XP ND in children, a primary neuronal degeneration that manifests first in the peripheral nervous system.

Age of Onset↗