In 31 patients with completed stroke (n = 30) or PRIND (n = 1) a brain SPECT with 123I-labeled amphetamines was performed. In 14 (= 45%) of the respective patients--suffering from long-lasting hemiplegia--crossed cerebellar diaschisis was present. The interval between onset of the disease and time of examination varied between 1 week and 7 years. On the other hand, patients without crossed cerebellar diaschisis did not, with one exception, suffer from hemiplegia. It is likely that this phenomenon is caused by the reduction of spino-cerebellar stimuli due to the paresis of the respective extremities.