1010 Bruxism and Non-functional Jaw Muscular Activity in the Disorders of Consciusness

Introduction In the last decades, the role of the neurophysiological techniques in the assessment of Disorders of Consciousness (DOCs) after severe acquired brain injuries has been enhanced, leading to a growing interest in this challenging field. However, only few works focused on the presence of bruxism or non-functional jaw muscular activity (NFJMA) in these patients. Here we present our experience in 32 patients assessed with a long lasting polygraphy (PG). Methods Thirty-two patients (14 females and 18 males, mean age 55.3 + 11.7 years) with prolonged or chronic DOC were consecutively enrolled as part of a national, multicentric clinical trial aimed at evaluating the tolerance and the efficacy of treatments for sleep disorders in DOC patients. All the patients underwent to a 24h PG visually inspected in order to determine the periods of wakefulness or sleep on the basis of PG pattern(s), as well as the occurrence of bruxism or NFJMA. Results Bruxism or NFJMA were found in 9 out of 31 patients, during periods of sleep (3 patients), awake (3 patients) or both (3 patients). We detected two forms of NFJMA in our case-series: a) a sustained (tonic) contraction of masseter and mylohyoid progressively weaker until returning to previous muscle tone in 2-10 seconds; b) phasic contractions of masseter and mylohyoid, detectable as a biphasic, waxes and wanes activity, typically lasting 0.25-0.5 seconds and usually repeated with pseudo-rhythmic intervals of 0.5-1.5 seconds and often limited to 4-15 events. In 3 patients muscular activity was continuous or subcontinuous for a very long time (up to 1.5 hours), always maintaining 0.75-1.5 Hz frequency. Conclusion Although much is unknown about the non-functional jaw muscular activity, our work demonstrated that the bruxism and NFJMA are very frequent in DOC patients. Support (if any) This research was funded by the Italian Ministry of Health GR-2016-02365049—Pilot Study on sleep pathologies treatments in patients with Vegetative and Minimally Conscious State diagnosis for improving Consciousness level: the STRIVE project.