Howard P. Krieger

Optokinetic afternystagmus in the monkey.

Abstract Optokinetic nystagmus and its afternystagmus was studied by recording of corneo-retinal potential with the electroencephalograph. This technique registers eye movements in light and dark, binocularly and uniocularly, with the eyes opened or closed, and does not interfere with the field of vision or the range of eye movement. Optokinetic afternystagmus is readily elicited from the monkey provided it is examined in darkness. The direction of these eye movements is determined by the antecedent optokinetic stimulus. The frequency and duration are only partially determined by this stimulus. Optokinetic afternystagmus is diminished and in time obliterated by light, but it may be brought out again by returning the animal to darkness thereby demonstrating that light merely makes the phenomenon latent and does not abolish it. This after response is suppressed by eyelid closure and sleep and can be reestablished by waking the animal. These observations may be analyzed in many ways, e.g. figure-ground relationships of the stimulus, the effect of sleep on eye movements, proprioceptive mechanisms, internuncial neuronal pools of reciprocating forces, but a definitive mechanism has yet to be worked out.

DISORDERS OF OCULOMOTOR FUNCTION IN LESIONS OF THE OCCIPITAL LOBE

FromtheDepartments ofNeurology ofNew YorkUniversity, Bellevue Medical Centre, andtheMountSinai Hospital, NewYorkCity Thephysician andeventheneurologist associates theoccipital lobewithvisual functions. Rarely doesoneattribute motordisturbance tolesions in this region ofthebrain. Whilethere isnodoubt thatnormalvision isdependent onintactness of thecalcarine cortexandthesubcortical optic radiations, there isapparently little clinical evidence toindicate thattheoccipital areaplays arolein themovements oftheeyes.Fromexperiments in animals andcortical stimulations inman itis apparent thattheoccipital lobemusthavean influence oneyemovements.

Effects on the brain of extracorporeal circulation in open heart surgery: A neurologic, electroencephalographic, psychometric, and neuropathologic study

MORE CONCERN has been expressed over the vulnerability of the brain than perhaps of any other organ in patients undergoing cardiac surgery with extracorporeal circulation. This communication describes the incidence of cerebral complications in 24 consecutive patients operated upon with the help of cardiopulmonary bypass at the Mount Sinai Hospital during 1958. This incidence was established by detailed clinical neurologic, electroencephalographic, and psychologic examinations before and after surgery. Neuropathologic study was performed in most of those patients who did not survive surgery.

Transient Glaucoma in Viral Encephalitis with Diencephalic Lesions

THIS REPORT deals with the simultaneous occurrence of transient glaucoma and viral encephalitis, principally affecting the diencephalon. The concurrence of these conditions may be merely coincidental. However, in view of the recent demonstration that intraocular pressure may be raised by stimulation of the diencephalonl and in view of the clinical suggestions that disease of the diencephalon may lead to glaucoma,2-* it is possible that glaucoma and encephalitis might be causally related in this case Since no similar case has been found in the literature, it was thought of interest to document these data.