Section to complete information about the inclusion and exclusion criteria for participant selection, including age and gender.
Inclusion criteria:
Inclusion criteria for patients •Persistent vegetative state patients were diagnosed according to current diagnostic criteria from the American Academy of Neurology • Patients showed eye movements with lack of fixation, no evidence of awareness of self or environment, lack of interaction with others, and no comprehension or expression of language. •Patients with an age no less than 16 years old •One month at least of clinical evolution Inclusion criteria for control normal subjects •Normal subjects, matched in sex and age with patients •Normal subjects did not have a history of any neurological or other chronic diseases, and they were not under any medication. •No history of being under medication such asr Zolpidem or a related benzodiazepine medication •Willingness to participate in the protocol
Exclusion criteria:
Exclusion criteria for patients •Patients who evidence of awareness of self or environment, some cognitive function, and interaction with others. •Patients with less than 16 years old •Less than one month of clinical evolution •Patients with the Diabetes Mellitus, or other systemic disease affecting the autonomic system Exclusión criteria for normal control subjects •Younger than 16 years old •Diagnosis of neurological, cardiologic, or other systemic diseases, •Presence de signs electrocardiographic signs of ischemia or arrhythmia •Being under the use of zolpidem, or other benzodiazepine drugs. •No willingness of participating in the protocol