Cerebrovascular reactivity during the Valsalva maneuver in migraine, tension-type headache and medication overuse headache.

The aim of this study was to investigate, by means of transcranial Doppler ultrasound (TCD), cerebrovascular reactivity during the Valsalva maneuver (VM) during the headache-free interval in patients with migraine (M), migraine plus tension-type headache (M+TTH), and migraine plus medication overuse headache (M+MOH). A total of 114 patients (n=60 M, n=38 M+TTH, n=16 M+MOH) and n=60 controls were investigated; diagnoses were made according to the International Headache Society criteria. All subjects underwent TCD monitoring and, simultaneously, non-invasive assessment of arterial blood pressure and end-tidal CO2. Two indices were determined: the cerebrovascular Valsalva ratio (CVR) was calculated as the maximum end-diastolic flow velocity acceleration during the late straining phase of the VM [cm/s2] and the centroperipheral Valsalva ratio (CPVR) was defined as the quotient of CVR to the concomitant arterial blood pressure acceleration [cm/mmHg x s]. The dynamic cerebrovascular autoregulatory response to the VM, measured as CVR, was increased in patients with M and M+TTH compared to age-matched healthy subjects. By contrast, CPVR (i.e. the quotient of the cerebrovascular to the peripheral autonomic response), was increased in M patients compared to healthy subjects and all other headache conditions tested. Cerebrovascular autoregulatory response during the VM was increased in M patients compared to age-matched normal healthy subjects, indicating a disturbed autonomic control of cerebral vasoreactivity. The CPVR seems to be a sensitive parameter for distinguishing between M patients and M+TTH or M+MOH patients.