PROGRESSIVE DEGENERATIVE ENCEPHALOPATHY

The data reported here may prove to be of importance in throwing additional light on the problem of Schilder's disease and related demyelinating or degenerative encephalopathies. It may also help to explain some of the clinical syndromes often attributed to birth trauma. "Swayback" in lambs has been shown by Innes and Shearer 1 to be of antenatal development, and even in those cases in which the condition was manifested at a considerable time after birth the defect probably began in utero. Innes and Shearer stated that "rarely only one of twin lambs was observed to be affected at birth, but in such cases the other often showed symptoms later in life. When only one of twin lambs is visibly affected at birth we do not know whether the other lamb remains permanently free from symptoms." There are many clinical and pathologic similarities between "swayback" and Schilder's disease, the latter being