title: Flow-diversion headaches in a patient with high-grade internal carotid artery stenosis.
abstract: BACKGROUND
  High-grade stenosis of the internal carotid artery (ICA) may result in flow diversion to the external carotid artery (ECA) and its branches. Head and facial pain secondary to flow-diversion to ECA and increase in regional blood flow are under-recognized and unreported.
  
  
  METHODS
  We report a patient with high-grade ICA stenosis and recurrent ipsilateral headaches that resolved after revascularization.
  
  
  RESULTS
  A 69-year-old woman presenting with right-arm weakness had neuroimaging evidence of ipsilateral high-grade ICA stenosis and left hemispheric ischemic stroke. Her history was significant for unilateral recurrent headaches that clinically resolved after left ICA angioplasty and stenting. With prior evidence supporting extracranial vasodilatation as the source of pain in migraine, and current clinical observation, we propose flow-diversion phenomenon as the connection between high-grade ICA stenosis and ipsilateral headache.
  
  
  CONCLUSIONS
  Recognition of flow-diversion into the ECA as a possible mechanism for headaches may help in further understanding of ICA disease, its progression, and the effects of carotid revascularization on quality of life. Headache as a likely surrogate marker of carotid stenosis with flow-diversion warrants more research, and may be critical in the early identification of significant ICA stenosis and prevention of TIA or stroke.
authors.affiliation: Zeenat Qureshi Stroke Institute and Department of Cerebrovascular Diseases and Interventional Neurology CentraCare Health, St. Cloud, MN 56303, USA.
authors.forename: Nabeel A
authors.initials: NA
authors.lastname: Herial
authors.affiliation: Zeenat Qureshi Stroke Institute and Department of Cerebrovascular Diseases and Interventional Neurology CentraCare Health, St. Cloud, MN 56303, USA.
authors.forename: Asif A
authors.initials: AA
authors.lastname: Khan
authors.affiliation: Zeenat Qureshi Stroke Institute and Department of Cerebrovascular Diseases and Interventional Neurology CentraCare Health, St. Cloud, MN 56303, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Thompson
authors.affiliation: Zeenat Qureshi Stroke Institute and Department of Cerebrovascular Diseases and Interventional Neurology CentraCare Health, St. Cloud, MN 56303, USA.
authors.forename: M Fareed K
authors.initials: MF
authors.lastname: Suri
authors.affiliation: Zeenat Qureshi Stroke Institute and Department of Cerebrovascular Diseases and Interventional Neurology CentraCare Health, St. Cloud, MN 56303, USA.
authors.forename: Adnan I
authors.initials: AI
authors.lastname: Qureshi
keywords: Carotid artery stenosis; carotid angiography; carotid stenting; facial pain; flow diversion; headache; magnetic resonance imaging