We studied an American kinship with sclerosteosis, an autosomal-recessive disorder of bone remodeling and bone overgrowth of the calvaria, skull base, and tubular bones. Unlike osteopetrosis, which is attributed to abnormal immune and osteoclast function as well as bone resorption, sclerosteosis appears to be primarily a disorder of osteoblast (bone formation) hyperactivity. Related to cranial vascular and neural foraminal narrowing and reduced intracranial volume, affected patients with sclerosteosis demonstrate frequent seventh nerve palsy, progressive optic and cranial neuropathies, mixed hearing loss, brainstem compression, intracranial hypertension with increased elastance, and sudden, premature death. Management should involve early childhood identification of homozygotes, monitoring and aggressive treatment of intracranial hypertension, and extensive bone removal from skull, posterior fossa, and cervical spine.

Long-term monitoring of intracranial pressure (ICP) was used as an aid for the management of four patients with pseudotumor cerebri. After the implantation of a small experimental pressure sensor in the skull, most of the subsequent (ICP measurements were made noninvasively by an external interrogator. During the initial study of the patient, baseline ICP recordings were made in the hospital before treatment. Pressure recordings on a 24-hour basis were continued during treatment, which, depending on the case, was with Diamox (acetazolamide), steroids, or the coperitoneal shunting. After discharge these patients returned weekly over 10 to 22 months for ICP measurement and for ophthalmological examination. Intracranial pressure before treatment showed irregular variations ranging from 100 to 500 mm H2O over a 24-hour period. The efficacy of treatments could be assessed in a few hours by the degree of ICP stabilization. Shunt malfunction was detected by a slow but continuous rise in pressure before full clinical signs were evident.

No abstract

No abstract

Patterns of discharge in slowly adapting, spontaneously discharging neurons of the cochlear nucleus were studied. A technique for analyzing the distribution of intervals between discharges of neurons is described. The response to a steady tone generally was an irregularly spaced train of impulses. In the majority of cells examined, the intervals between discharges were distributed exponentially. The mean interval and standard deviation of the distributions decreased as the level of afferent excitation was increased, but the modal value of the distribution was unchanged.