Mismatch negativity and N100 in comatose patients

Mismatch negativity (MMN) and N100 auditory evoked potential were recorded in 52 healthy subjects and in 128 severely comatose patients. The MMN was p resent in 33/128 patients and N100 in 84/128. A ratio of 30/33 patients wit h MMN and 70/84 with N100 regained consciousness in a mean time of 6.3 +/- 4 days after the recording session. Thus, in terms of predicting return to consciousness, the MMN was more specific (90.9%) than the N100 (57.6%), but its sensitivity was lower (31.6% for MMN and 73.7% for N100, respectively) . The amplitudes of MMN and N100 in comatose patients were smaller than tho se of healthy subjects. It is concluded that MMN and N100 can be very usefu l in predicting whether or not a comatose patient will regain consciousness . Copyright (C) 2000 S. Karger AG, Basel.