Pathophysiology of migraine attack with prolonged aura revealed by transcranial Doppler and near infrared spectroscopy

The aim of this study is to identify the pathophysiology of migraine attack with prolonged aura (between 1 h and 7 days) not clearly understood. We studied cortical cerebral microcirculation by an innovative near infrared spectroscopy system (NIRS) and cerebral macrocirculation by trancranial Doppler (TCD) in eight subjects (3 M and 5 F, age range 21–41 years) during spontaneous prolonged migraine aura and after 1, 2, 4, 6, 12 and 24 h since the end of aura and compared the results with the headache-free periods. During aura NIRS showed a significant decrease of the arterial pulse wave of cerebral microcirculation (APWCM) amplitude (−35%), p < 0.002, and an increase of cerebral tissue oxygen saturation (SctO₂) (+15%), p < 0.008 ipsilateral to the headache pain and contralateral to the symptoms of aura compared with the headache-free periods; TCD showed a significant increase of pulsatility index (+38%), p < 0.001 and a significant decrease of the diastolic velocity in the posterior and middle cerebral artery ipsilateral to the headache pain and contralateral to the symptoms of aura compared with the headache-free periods. During prolonged migraine aura we found areas of cortical hypoperfusion corresponding to the topography of aura symptoms that were the result of a decreased metabolic demand rather than ischemic mechanism.