1049 Are the AASM Scoring Rules Fitting for the Sleep of Patients with Chronic Disorders of Consciousness?

Abstract Introduction From a neurobiological perspective, consciousness and sleep are strictly related. It is known that regular sleep patterns may reflect the preservation of brain functions. Detailed sleep assessment Disorders of Consciousness (DOC) patients is a controversial issue. Methods Twenty-two patients (11 females and 11 males, mean age 52.2 + 14.5 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 polysomnography (PG) visually inspected in order to assess their sleep stages on the basis of the AASM scoring rules. Results All the patients except one slept for at least 4 hours. Ten out of 21 (47.6%) patients showed a sleep lacking the features necessary for scoring; nor spindles neither K-complexes were present, the delta waves, if present, were localized; the polygraphic features of REM stage were absent. In our cases, sleep differed from wakefulness only by the decrease in muscle tone and by the reduction of eye movements and muscle artifacts on the EEG, as well as by the modification in the heart rate and heart-rate variability. Furthermore, in 4 out of 10 DOC patients with “indistinct” sleep, EEG pattern was characterized by very low voltage activity (< 20 microV), similar to what is observed in cases of deep sedation. Conclusion Our data push in the direction that a standardized sleep assessment procedure in DOC should be stabilized. 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.