The publication "Ischemia May Be the Primary Cause of Neurological Deficits in Classic Migraine" by Skyhøj Olsen et al1 is being increasingly cited as a source of evidence that the brain is ischemic during migraine attacks. We have, after perusal of the article, found several fallacies that undermine the authors' conclusions. The article sought to examine the effect of Compton scattered radiation on the measurement of regional cerebral blood flow (rCBF) in patients with classic migraine. The rCBF measurements were performed with the intracarotid xenon 133 technique² and a gamma camera with 254 collimated scintillation detectors covering the lateral aspect of the hemisphere. The spatial resolution is of the order of 1 cm. Measurements (2 to 8) were performed in the resting condition during the migraine attacks in each of the 11 patients, and a total of 42 studies were carried out. For each measurement.