Circadian rhytms in the Vegetative State

TRISTÁN BEKINSCHTEIN; DIEGO GOLOMBEK; SERGIO SIMONETTA; MARTÍN COLEMAN; FACUNDO MANES

Washington

Encuentro; 61st AAN 2009 Annual Meeting; 2009

American Academy of Neurology

OBJECTIVE: To evaluate whether patients in the vegetative state maintain circadian rhythms we studied five chronic vegetative state patients. BACKGROUND: The vegetative state is defined as a condition of wakefulness without awareness and cycles of eye closure and eye opening, but there is no empirical evidence of circadian rhythms in these patients. DESIGN/METHODS: Clinical and neurological evaluations and two-weeks continuous temperature measurements were recorded. RESULTS: Results revealed two traumatic brain injury patients showing well-formed circadian temperature rhythms who also displayed a wider portfolio of reflexive behaviours and less cortical and subcortical atrophy as compared to patients with no cycles or rhythms (from anoxic-hypoxic origin).CONCLUSIONS/RELEVANCE: The presence of periods of wakefulness does not imply preserved sleep-wake cycling capacity, nor preserved circadian rhythms, and it should not be taken as distinguishing feature for the definition of the vegetative state.