Histological reaction to various conductive and dielectric films chronically implanted in the subdural space.

Thirty different test patches of various thin film materials were chronically implanted in the subdural space of cats to determine their suitability as components for proposed neuroprosthetic devices. In particular, materials employed by the microelectronics industry were screened, and reactions were found to be quite dependent on specific formulations or surface preparations of otherwise similar materials. A nonspecific but severe complication of pressure necrosis under thin films that spontaneously roll and curl in vivo was noted.

Progressive quadriparesis, mental retardation, retinitis pigmentosa, and hearing loss: report of two sibs.

Three- and four-year-old brothers, ostensibly with a nonprogressive spastic quadriparesis, had retinitis pigmentosa and mental retardation. One had clinical deafness. The brothers showed little developmental progress in infancy and exhibited deterioration in childhood.

Olivopontocerebellar degeneration. Clinicopathologic correlation of the associated retinopathy.

In two siblings with olivopontocerebellar degeneration, the retinal pigment epithelium or the sensory retinal or both appeared to be damaged first. These layers were markedly involved before secondary changes in the choriocapillaris, the inner retinal layers, or the optic nerve occurred.

Syndromal approaches to the nosology of hereditary deafness.

Seventy types of hereditary deafness can be distinguished using the following features of the syndrome: 1) mode of genetic transmission, 2) characteristics of the deafness, 3) age of onset, 4) sonic frequencies involved and 5) associated abnormalities. The gene, in single or double dose, causing the hearing loss may also cause abnormalities of the external ear, or of the integumentary, visual, nervous, skeletal, or urinary systems. In this report the characteristics of the hearing loss in each of the types of hereditary hearing loss are reviewed in eight tables.