A Form of Progressive Cerebral Sclerosis in Infants Associated with Primary Degeneration of the Interfascicular Glia.

PROGRESSIVE cerebral sclerosis in young children assumes two main forms for which the generic names of amaurotic family idiocy and progressive centrolobar sclerosis are perhaps the most suitable. The first has during the past 20 years largely yielded up its secrets to the histological investigations of a number of workers. The studies on neuronal metabolism in this disease by Marinesco, and of its Mendelian characteristics by Sj6gren, deserve special mention in this connexion. Of the second form we know less, and the theories which have been advanced to account for it are largely speculative. Bielschowsky and Henneberg have divided cases of this kind into two main groups, the non-familial type of Schilder which they assume to be due to an exogenous infection, and a familial type which is attributed to an endogenous degenerative process. The latter has again been divided according to ageincidence into the infantile type of Krabbe, the juvenile type of Scholz and the slowly progressive type of Pelizaeus and Merzbacher. This division is somewhat arbitrary, since there is increasing evidence that many of the cases which have been described as Schilder's ' encephalitis periaxialis diffusa ' are familial. Thus Collier and Greenfield's case II appeared at first to be isolated, but three younger children of the family have since become affected on reaching a similar age; the post-mortem examination of the first two of these has revealed lesions in the brain which are almost identical with those described in the first child. It is noteworthy that in most families, though not in that of Symonds, the disease appears at the same age and runs a similar course in each of the members affected; it is no longer possible to describe a few main types, according to age of incidence and rapidity of involvement of the cerebral functions, seeing that the type varies with each affected family.