A 41-year-old female with history of migraine presented to the ED with acute onset of aphasia. In addition to the aphasia, there was numbness and tingling in the right arm and face. Patient demonstrated expressive aphasia and was not able to answer questions posed in the ED. Gadolinium MR perfusion images demonstrated decreased relative cerebral blood flow (top) in the left parietal/occipital lobes and increased time-to-peak (bottom) in the contralateral cerebellar hemisphere. Although crossed cerebellar diaschisis (CCD) is seen mostly on radiotracer studies (hypometabolism on PET studies), it was nicely demonstrated in our patient. CCD occurs more often after supratentorial infarctions but has been reported in the setting of migraine. This phenomenon occurs immediately after brain injury due to the large number of functional connections between cerebrum and cerebellum. In reverse CCD, the brain abnormality is due to injury of the cerebellum. Because of the limited number of slices on perfusion MR studies, particularly when using ASL techniques, it is important to keep in mind that the cerebellum may be involved in several supratentorial abnormalities and needs to be included in the study.  I would be interested in finding out if anyone else has seen this type of migraine-associated CCD.