Inclusion Criteria - Migraine (N=20):  Female only. Ages 20-45 years. Presence of WMH on MRI.  Exclusion Criteria:  History of SVI and/or history of MS or other neurological disease other than migraine. History of cancer or organ transplantation. Contraindication to MRI. Pregnancy. History of abnormal brain MRI other than WMH. Subjects not willing to comply with the study procedures will be removed from the study.  Inclusion Criteria - SVI disease (n=10):  Female only Ages > 60 years. Presence of WMH on MRI.  Exclusion Criteria:  History of migraine and/or history of MS or other neurological disease other than SVI. History of cancer or organ transplantation. History of abnormal brain MRI other than WMH. Pregnancy. History of abnormal brain MRI other than WMH. Subjects not willing to comply with the study procedures will be removed from the study.  Inclusion Criteria - MS (n=10):  Female only. Ages 20-45. Presence of WMH on MRI.  Exclusion Criteria:  History of migraine and/or history of SVI or other neurological disease other than MS. History of cancer or organ transplantation. History of abnormal brain MRI other than WMH. Pregnancy. History of abnormal brain MRI other than WMH. Subjects not willing to comply with the study procedures will be removed from the study.