2025 Volume 52 Issue 1 Pages 32-38
We have devised a new method of medical management of migraine using magnetic resonance imaging-arterial spin-labeling (ASL) images during the interictal period of migraine. As an imaging diagnosis for migraine, cortical hyperperfusion (CHP) on ASL is useful, although it is less frequent in cases with insomnia. If migraine is clearly diagnosed according to the diagnostic criteria, but no CHP findings are evident, insomnia should be suspected, and psychological examinations should be required. CHP findings on ASL are clinically very useful as one of the supplementary diagnostic tools in addition to interviews, as the only impressive imaging finding for migraine at present.
Among patients complaining of scintillating scotoma without headache (typical aura without headache: TAWH) , those with CHP findings have migraine features such as a family history of migraine and sensory hypersensitivity, and share clinical characteristics similar to those of migraine with aura. Other TAWH patients had no family history of migraine or clinical characteristics, and often did not have CHP findings on ASL. In addition, they often had organic diseases such as stenosis of the posterior cerebral artery that nourishes the visual center and reduced cerebral blood flow in the same area, and were cases with risk factors for stroke.
Next, we performed interictal ASL before and after anti-CGRP therapy in migraine patients, including those who had undergone antibody switching, to investigate subsequent changes in CBF and identify predictors of treatment response. Multivariable analysis revealed that significant negative neuroradiological predictors of ＞50％ responders were CHP findings despite presentation with insomnia and insomnia with white matter hyperintensities. On the other hand, the changes after anti-CGRP therapy in CBF were classified into four groups: 1) CHP findings before treatment and a decrease in CBF after treatment (group A) , 2) no CHP findings before treatment and an increase in CBF after treatment (group B) , 3) no CHP findings before treatment and a decrease in CBF after treatment (group C) , and 4) no change in CBF before and after treatment (group D) . The efficacy rate of over 50％ in each group was highest in group B (about 95％) and lowest in group D (about 10％) . In group B, all patients had insomnia before treatment, and many patients had improved insomnia after anti-CGRP therapy. We speculate that CBF increased because the glymphatic system disorder caused by insomnia was improved. The CBF changes after anti-CGRP therapy in Groups A and B are changes in which CBF approaches normal (optimization) , and can be said to be “appropriate changes.” Conversely, in group C, about 95％ patients had insomnia, but only about 10％ patients had improved insomnia after treatment. Furthermore, many patients in group C showed an inappropriate decrease in CBF below the normal range after treatment and should be monitored for the occurrence of cerebral infarction. In conclusion, ASL findings were also useful for predicting and evaluating the therapeutic effect of anti-CGRP therapy.
