The head-up tilt test and the differential diagnosis between epileptic attacks and syncope. Case report

Often patients who have undergone a false diagnosis of epileptic attack have actually been affected by syncope. One of the most common causes of such misdiagnosis is an abnormal interictal electroencephalographic (EEG) trace. The purpose of this paper is to suggest the usefulness of the head-up tilt test as a differential diagnosis between epileptic attack and syncope. Patients underwent the head-up tilt test, which was considered positive only if the syncopal symptomatology was reproduced. The subjects were patients in a neuropsychiatric clinic. Four patients with a positive anamnesis due to brief episodes of unconsciousness and to falls were assessed. All 4 patients showed an abnormal EEG with focal spikes and sharp-waves. The head-up tilt test produced a syncope in all 4 cases. In the symptomatology evoked by the test the patients and their parents recognized the exact same characteristics of those episodes for which they had sought consultation, so a diagnosis of a vasovagal syncope of 3 different types was made. The head-up tilt test proved appropriate to differentiate syncope from epileptic attacks in patients with symptoms of unconsciousness, falls and interictal EEG spikes or sharp-waves.