Alcohol intoxication: a risk factor for primary subarachnoid hemorrhage.

We studied 172 consecutively presenting patients (88 men and 84 women; aged 15 to 55) with primary subarachnoid hemorrhage (SAH) verified by hemorrhagic CSF or at autopsy. In 37 (22%) of the patients, the onset of symptoms was preceded within 24 hours by alcohol intoxication. Alcohol intoxication preceding SAH was two to three times as common in men and two to thirteen times as common in women as alcohol intoxication in the general Finnish population of the same age and sex. Thirty-two (19%) of the patients were heavy drinkers. Heavy drinking was twice as common in men and seven times as common in women as heavy drinking in the general Finnish population of the same age and sex. Both occasional ethanol intoxication and regular heavy drinking seem to carry an increased risk of SAH.