The Electro-encephalogram in Blind Children.

THERE have been surprisingly few studies of the electro-encephalogram (EEG) in blind persons, and the first report appears to be that of Adrian and Matthews (1934) on the absence of alpha rhythm in totally blind subjects. Further reports on the alpha rhythm were made by Loomis, Harvey, and Hobart (1936), Lemere (1942), Callahan and Redlich (1946), Redlich, Callahan, and Mendelson (1946), Drever (1955), Bergman (1956), and Bergman and Jaffe (1961). Most of these studies concerned only a few patients. Lairy and Netchine (1961) reported on a group of fifty blind children, but gave little information about the alpha rhythm. There are a number of papers on the EEG findings in retrolental fibroplasia (Jim and Krause, 1954; Gibbs, Fois, and Gibbs, 1955; Kellaway, Bloxsom, and Macgregor, 1955; Cohen, Boshes, and Snider, 1961), but these deal mainly with paroxysmal and focal EEG abnormalities and, with the exception of Cohen and others (1961), few authors report on the alpha rhythm. There is little information about the relation ofthe EEG findings to the degree of blindness or its time of onset, although Drever compared cases of early and late onset. Levinson, Gibbs, Stillerman, and Perlstein (1951), Stillerman, Gibbs, and Perlstein (1952), and Gibbs and Gibbs (1952) studied the EEG in a variety of eye disorders, especially strabismus, and Krill and Stamps (1960) and Lesny (1961) described the EEG findings in retinitis pigmentosa, the former authors commenting on the alpha rhythm. The aim of the present study was to establish whether any particular EEG pattern was associated with blindness, to assess the alpha rhythm in relation to presence or absence of vision, and to see if there was any relation between the alpha rhythm and the degree and duration of the blindness. Since the series contains a large number of cases of retrolental fibroplasia, special mention will be made of these cases, and the relation of various causes of blindness to EEG abnormalities will also be examined. It is felt that some ophthalmologists may not be familiar with the terms used in electro-encephalography, and a brief account of these, and of the normal findings, is therefore given.