The use of placebo as a provocative test in the diagnosis of psychogenic non epileptic seizures

Abstract

Psychogenic non epileptic seizures (PNES) are clinical events of psychological nature. Video-electroencephalography monitoring (V-EEGM) is a valuable method for the diagnosis of PNES and may be combined with provocative tests to induce seizures. The use of placebo in provocative tests for the diagnosis of PNES is controversial because of associated deception, and contrasts with the use of truly decreasing epileptogenic threshold techniques such as hyperventilation and photo stimulation. We present a clinical case of a pregnant woman with a past history of refractory epilepsy, admitted in the obstetric department due to unremitting seizures. In this clinical context, non-deceiving provocative tests such as hyperventilation and photo stimulation could be potentially harmful, nevertheless, the use of intravenous saline injection presented as a safer alternative to diagnose PNES and hence obviate an urgent caesarean. This case illustrates a disproportionate risk of causing harm when telling the truth, in comparison with the benefit of avoiding such risk, although deceiving the patient. This is a clinical example of how considerations concerning the use of placebo must be evaluated in an individual basis.