[A patient with an unexplained loss of consciousness: a case for the neurologist or the cardiologist?].

Three patients, a woman aged 62 and two men aged 22 and 77 years respectively, were admitted because of an unexplained loss of consciousness. In the woman and younger man these complaints were caused by a vasovagal reaction, and in the older man by hypersensitivity of the carotid sinus. In a hospital setting, the examination of patients with a loss of consciousness often leads to discussions between the neurologist and the cardiologist. Elaborate additional testing seldom reveals epilepsy or cardiac arrhythmia as the cause. A thorough medical history can exclude both diagnoses in almost all cases. Physicians should be aware that most patients experience a vasovagal syncope and that this might be triggered by very common circumstances. Knowledge of these triggers and the epidemiology of loss of consciousness might prevent the patients from being examined by different specialists and undergoing unnecessary additional tests.