Wallerian degeneration of the descending tracts. CT and MRI features of the brain stem.

The authors have studied by CT brain infarcts of different ages in 16 patients, two of whom were also examined by MRI. The early and CT signs of wallerian degeneration of the descending tracts within the brain stem are described. Three cases of crossed cerebellar atrophy are reported; in one of them, the cerebral lesion had been present for less than 8 years. The physiopathology of pontine hemiatrophy and crossed cerebellar atrophy is discussed.