title: Study of neurovascular coupling during cold pressor test in patients with migraine.
abstract: BACKGROUND
  Altered neurovascular coupling in migraineurs could be a consequence of impaired function of modulatory brainstem nuclei. The cold pressor test (CPT) should activate brainstem structures. We measured visually evoked cerebral blood flow velocity response (VEFR) to CPT in migraine.
  
  
  METHODS
  Twenty-three healthy volunteers and 29 migraineurs participated in the study. We measured arterial blood pressure, end-tidal CO2, heart rate and cerebral blood flow velocity in posterior and middle cerebral artery using transcranial Doppler. VEFR was calculated as cerebrovascular reactivity to photic stimulation before, during and after CPT.
  
  
  RESULTS
  In healthy individuals, there was a significant decrease in peak systolic VEFR from CPT phase to recovery phase (p < 0.05). There was an increase in mean VEFR from basal to CPT phase and a decrease from CPT to recovery phase, both significant (p < 0.05). End-diastolic VEFR increased from basal to CPT phase and decreased in recovery phase below the basal phase values, all changes significant (p < 0.05). In migraine, no statistically significant changes in peak systolic, mean or end-diastolic VEFRs were observed between phases (p > 0.05). The differences in phases in mean and end-diastolic VEFRs between the basal phase and the CPT phase and between the CPT phase and the recovery phase were significantly higher in healthy individuals (p < 0.05).
  
  
  CONCLUSIONS
  The absence of the effect of CPT on VEFR in migraine is likely to be a consequence of impaired subcortical modulation of neurovascular coupling.
authors.affiliation: Institute of Physiology, Medical Faculty, University of Ljubljana, Slovenia andrej.fabjan@mf.uni-lj.si.
authors.forename: Andrej
authors.initials: A
authors.lastname: Fabjan
authors.affiliation: Institute of Pathophysiology, Medical Faculty, University of Ljubljana, Slovenia University Medical Centre of Ljubljana, Department of Vascular Neurology, Slovenia.
authors.forename: Fajko F
authors.initials: FF
authors.lastname: Bajrović
authors.affiliation: Jožef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Bojan
authors.initials: B
authors.lastname: Musizza
authors.affiliation: Institute of Physiology, Medical Faculty, University of Ljubljana, Slovenia.
authors.forename: Jernej
authors.initials: J
authors.lastname: Vidmar
authors.affiliation: Institute of Physiology, Medical Faculty, University of Ljubljana, Slovenia.
authors.forename: Martin
authors.initials: M
authors.lastname: Štrucl
authors.affiliation: University Medical Centre of Ljubljana, Department of Vascular Neurology, Slovenia.
authors.forename: Marjan
authors.initials: M
authors.lastname: Zaletel
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000503:physiopathology*; D000069336:Neurovascular Coupling / Q000502:physiology*; D017585:Ultrasonography, Doppler, Transcranial
keywords: Migraine; cold pressor test; evoked cerebral blood flow velocity response; neurovascular coupling; transcranial Doppler