Acute haemorrhagic leuco-encephalitis.

was concerned to the white matter, and developing more or less abruptly in apparently normal individuals. Perivascular necroses, perivascular and focal demyelination, haemorrhages, oedema, and cellular infiltration were the chief components of the pathological picture." In the 12 years since Hurst's paper appeared remarkably few similar cases have been reported, and in fact only five further examples have been described under the same name. These have been recorded by Henson and Russell (1942), Shallard and Latham (1945), MacArdle, van Bogaert, and Lhermitte (1949, two cases) and by Greenfield (1950). It so happens that three characteristic examples of the disease have occurred in the neurosurgical department of St. George's Hospital