METAMORPHOPSIA AND OTHER VISUAL DISTURBANCES WITH LATENCY OCCURRING IN PATIENTS WITH DIFFUSE CEREBRAL LESIONS

Among the phases of reniisson of blindness following gunshot wounds in the back of the head PotzZ (1928) described one phase which he called cerebral asthenopia. The characteristic finding in this phase is an abnormal fatiguability of the structures subserving the functions of sight. When the patients fix their eyes on an object this is a t first seen clearly, but if fixation lasts for more than a few seconds the object becomes blurred, and auto-kinetic phenomena, diplopia or dimness of vision may occur. These disturbances disappear when the patient alters the point of fixation but develop again if fixation is maintained:During the cerebral asthenopic phase reading is hindered by the fact that the letters dissolve into the background, or else appear double. The lines may appear as black stripes. After a brief pause the patient is, however, able to read normally again, but the same disturbances will recur after he has read for a short time. It is the purpose of the present article to report similar visual disturbances which have been registered in a group of neurological patients, on all of whom air encephalography had been performed, and the majority of whom had diffuse cerebral atrophy. An attempt will be made to give a more precise definition of some of the more important visual changes which occur in these patients. Gtoning, Gtoning & Tschabitscher (1962), in a material of 16 cases of occipital blindness due to vascular lesions, have confirmed the remission phases described by Potzl, including the occurrence of cerebral asthenopia. In a material comprising patients with parietal and occipital gunshot wounds Bay (1950) demonstrated experimentally the way in which a number of qualitative aspects of vision fluctuated (“Funktionswandel”) . He describes the visual experience as being subject to