THE SPECTRUM OF SYNCOPE

Syncope is a loss of consciousness and postural tone. Although arising suddenly from prolonged recumbency or returning from weightlessness t o Earth's gravity con result in syncope from orthostatic or vasovagal effects, there are many other possible causes. These causes can be div ided into several groups. Causes listed in the cardiovascular category , especially cardiac causes, are more likely to occur in the elderly; noncardiac causes are more common in the younger population. The cases described herein illustrate the often unexpected mechanisms of syncop e in otherwise healthy individuals. Two of the cases emphasize the use fulness of prolonged combined EEG/EKG monitoring. The categories of lo ss of consciousness experienced by air crew members are reviewed. The most important screening tool in identifying the mechanism(s) of synco pe is a detailed history emphasizing a search for underlying disease, the specific associated circumstances, and pre- and post-event symptom s. The type of diagnostic studies, i.e., cardiac or neurologic, undert aken should be based on the historical data. Seizures must be consider ed as a possible mechanism of otherwise unexplained loss of consciousn ess in nonelderly persons, including air crew members.