Repeated measurements of the auditory oddball paradigm is related to recovery from the vegetative state

The auditory oddball response has been found to be of predictive value for neurologic outcome at the early stages of coma. In the present study, the auditory oddball response was examined longitudinally during the recovery from the vegetative state to consciousness. This response was repeatedly examined every 2 weeks for an average period of 3.5 months in severely brain-injured patients. Results showed that amplitude of the auditory oddball response was unrelated to the behavioral changes during the patients' recovery from the vegetative state to consciousness. However, the presence and size of a negative potential at about 350 milliseconds predicted behavioral outcome, both for the short and long term (2 to 3 years after injury). Practical and theoretical implications of these findings are discussed.