Circadian and ultradian rhythmicity in patients with disorders of consciousness

Background and aims: The Unresponsive Wakefulness Syndrome and Minimally Conscious State (UWS; MCS) are characterized by the absence or the presence but severe disordered signs of consciousness in spite of the presence of preserved sleep-wake cycles. Spectral entropy has used to find periodicity on EEG signals of DOC (disorders of consciousness) patients. Circadian and ultradian are fisiological rhythmits found in all living organisms.
Methods: We used data from 126 patients (controls, EMCS, LIS, MCS, MCS+, MCS-, MCS*, and UWS). We recorded the movements on the wrist for 7 consecutive days, then we use average 5 complete days in 24 hours to compute the circadian rhythmicity and in 120 min to compute the
ultradian rhythmicity. Spectral entropy is used to compute to find the signficant diffference inthe amplitude of the movements and its periodicity (spectral amplitude) is used to find the rhythmicity.
Results: We have found a circadian rhythmicity in DOC patients within 18 hours in average and and ultradian rhythmicity between 40 to 80 min.
Conclusion: The actigraphy can give useful information about the circadian and ultradian rhytmicity in DOC patients.