Multimodal tests of cerebrovascular reactivity in migraine: a transcranial Doppler study

Altered cerebral vasoreactivity (CVR) has been implicated in migraine. To test this hypothesis, we studied CVR as measured by transcranial Doppler ultrasound (TCD) in 11 migraineurs and 12 healthy controls of similar age. Mean flow velocities (MFV) in the middle cerebral artery (MCA) were recorded during a cognitive and two motor tasks. MFV in the posterior cerebral artery (PCA) were measured during photic stimulation and observation of complex images. The increase of MFV in the MCA during the cognitive task was greater in migraineurs than in controls (9.1% vs 5.0%; P = 0.06). The increase of MFV in both tests for PCA reactivity was significantly greater in migraineurs than in controls: 17.4% vs 9.9% for photic stimulation (P less than 0.05) and 20.3% vs 10.2% for observation of complex images (P less than 0.05). Owing to overlap of individual results, the discriminative value of both tests was unsatisfactory. The variability of flow velocities as measured by standard deviations of MFV was significantly greater in migraineurs than in controls during all tests of PCA vasoreactivity. Differences in CVR between migraineurs and normal controls may be detected by TCD testing, in particular in the PCA territory. For individual diagnostic purposes, CVR tests proved to be insufficient.