[Primary loss of consciousness and amnesia in subarachnoid hemorrhage--a quantitative study].

Subarachnoid hemorrhages (SAH) being sudden events affecting the brain in a rather wide-spread fashion are apt to induce loss of consciousness (LOC) and amnesia. The aim of the present study was to collect data on their frequency and extent. To this end we examined 48 patients at a mean of one year post-onset. Two thirds of them reported anterograde and an additional 17% retrograde amnesia; in 40% LOC (median 6 minutes) was observed. The durations were extremely skewed towards shorter times with a median of 2.7 days for anterograde and 1.3 days for retrograde amnesia who--with a single exception--were markedly shorter than anterograde amnesia. Summing up, a significant proportion of all SAH suffered LOC and amnesia occurred in the majority of cases. SAH therefore are events which with respect to LOC and amnesia bear some resemblance with closed head injuries. Exact observation and history taking may disclose important data on their severity and possible sequelae.