Nocturnal headache: systemic arterial pressure and heart rate during sleep.

In order to evaluate autonomic nervous system changes occurring before nocturnal headache attacks, we studied three subjects (one male, two females) suffering from chronic migraine. All three patients underwent a nocturnal polygraphic recording including continuous monitoring of systemic arterial pressure and heart rate. Two subjects showed increases and irregularities of arterial pressure before awakening with headache. These changes began during N-REM sleep and lasted during REM sleep preceding the awakening with headache. Heart rate did not change before the attacks. These findings do not support the hypothesis that autonomic instability during REM sleep represents the precipitating factor of the attacks.