Medical Hypnosis Against Anxiety and Pain in Electro-neuro-myography

Medical hypnosis is more and more used during some medico-technical investigational procedures, such as interventional radiology, dental procedures, baby deliveries. Using the modified conscious state induced by trance or by conversational hypnosis (thanks to verbal and nonverbal language) allows a better tolerance of these procedures. Only very few situations recommend against this approach. ENMG is a frequently performed procedure in neurology to explore neuromuscular functions. It implies electric stimulations, needle insertion and needs the patient cooperation and the patient's well-being. This is all the more necessary that this procedure may be repeated for a patient along his/her life. Only one study evaluated the effect of hypnosis on pain and anxiety during ENMG (Slack and al., 2009). Despite a low statistical power due to a small sample, it showed a reduction of the maximal pain during the needle electromyography. More proof is therefore needed to assess the efficacity of hypnosis against pain and anxiety during ENMG. Several members of our nurse and medical team have an experience in hypnosis practice and this procedure is sometimes used in some patients, when specifically required, alone or with other analgesic procedures (like nitrous oxide), but not in the current standard practice. This is mainly useful in patients with anxiety. This study's principal objective is then to evaluate the effect of an hypnosis procedure, compared to a standard clinical procedure alone, on pain consecutive to ENMG, in patients presenting with anxiety when attending an ENMG. The secondary objective is to assess the effect of hypnosis on anxiety consecutive to the ENMG. This is a monocentric, controlled, randomized, open-labeled study, with two balanced arms. The study cannot be blind since the members of the staff will apply at the same time the hypnosis procedures and the ENMG investigations. Patients who have to undergo an ENMG due to their standard care investigations will be consecutively included as long as they're taken care of by members of the staff with an hypnosis experience and express any anxiety. 48 patients in each group will have to be include to achieve a sufficient power. Statistical analyses will be blindly performed by our methodology, biostatistics and data management unit. All tests will be bilateral with an alpha risk of 5%, with an intention-to-treat procedure. Our hypothesis is a reduction of pain and anxiety in the hypnosis group compared to the standard care one. If this is confirmed, it will be an argument to offer this procedure in a systematic way to any patient with anxiety who has to undergo an ENMG as well as developing its use in other electrophysiological investigations.