Bekinschtein T, Diego Golombek, Simonetta S, Coleman MR, Manes F. Circadian rhythms in the vegetative state. Brain Injury 2009
OBJECTIVE: To evaluate whether vegetative state patients maintain circadian rhythms. RESEARCH DESIGN: An observational study of five single cases. METHODS AND PROCEDURES:Five chronic vegetative state patients underwent clinical and neurological evaluations and 2-week continuous temperature measurements. MAIN OUTCOMES AND RESULTS: The two patients with traumatic brain injury showed well-formed circadian temperature rhythms and had more reflexive behaviours and relatively low cortical and sub-cortical atrophy, whereas the three patients from anoxic-hypoxic origin demonstrated no cycles or rhythmic behaviour. CONCLUSIONS: 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 a distinguishing feature for the definition of the vegetative state.