Our results indicate that the flocculus and possibly paraflocculus participate in the control of oculomotor reflexes that insure best visual acuity by preventing retinal slip. The flocculus serves both the specific needs of the fovea (pursuit, saccades, and gaze holding) as well as the phylogenetically older requisite for stabilization of images on the retina during head rotation (VOR and OKN). 9. The unpredictable effect of flocculectomy on VOR gain, postsaccadic drift, and the waveforms of vertical nystagmus may reflect the basic regulatory role of the cerebellum so that inherent imperfections in oculomotor performance are exposed by removal of the flocculus.

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.

1. Eye movements were recorded before and after bilateral occipital lobectomy in six rhesus monkeys trained to fixate and to follow small targets. Striate cortex was completely removed in two animals; small islands islands remained in the others. In all animals portions of extrastriate cortex were also removed but the medial superior temporal area in the superior temporal sulcus was largely spared. Optokinetic nystagmus (OKN) was markedly altered but not abolished in all animals. The immediate pursuit component of OKN was eliminated leading to a poor response to stimuli comprised of high frequencies. The velocity-storage component of OKN was present, but the maximum value of OKN that could be achieved was decreased to 6 and 16 degrees/s in the two most severely affected animals (preop, 65-116 degrees/s). The residual OKN was similar to that of afoveate animals with a diminished response to high velocities of retinal-image motion and a temporal to nasal predominance during monocular viewing. 2. In the initial postoperative period all animals appeared completely blind. Within 1-6 mo, however, they regained an ability to make visually guided saccades to, and smooth pursuit of, small targets. Saccades were nearly as accurate as preoperatively, but saccade amplitudes were more variable and saccade latencies increased. In the two animals with a complete removal of striate cortex, gains (eye velocity/target velocity) of smooth pursuit during sinusoidal tracking (60 degrees/s, 0.5 Hz) were 0.9 and 0.95. During tracking of step-ramp (Rashbass) stimuli with 60 degrees/s ramps, the average acceleration of the eyes during the first 120 ms of smooth pursuit was 189-278 degrees.s-1.s-1 (preop range, 154-418 degrees.s-1.s-1). In other respects, though, smooth pursuit was not normal. Latencies were increased two- to threefold, and tracking was more variable. 3. Paradoxically, as visually guided saccades and pursuit recovered, some other ocular motor functions deteriorated. Spontaneous and gaze-evoked nystagmus developed 3-6 mo after occipital lobectomy; the time constant of the neural eye-position integrator dropped to values as low as 2.6-4.8 s. The maximum slow-phase velocity of OKN also decreased. 4. The findings immediately after occipital lobectomy indicate that in normal primates occipital cortex is necessary for visually guided saccades and smooth pursuit as well as for the immediate component of OKN. Occipital cortex also makes the predominant contribution toward the generation of the velocity-storage component of OKN.(ABSTRACT TRUNCATED AT 400 WORDS)