Somatosensory evoked potential amplitudes correlate with long-term consciousness recovery in patients with unresponsive wakefulness syndrome.

Abstract Objective To prospectively investigate relationships of cortical somatosensory evoked potential (SEP) amplitudes with consciousness recovery and disability in the year following brain injury in patients with vegetative state/unresponsive wakefulness syndrome (VS/UWS). Methods SEPs of 42 patients with VS/UWS were recorded 51.7 ± 23.3 days post-injury. N20–P25 amplitudes were compared between patients with and without consciousness recovery at 6 months and 1 year post-injury. Results SEPs were present in 21 patients and bilaterally absent in 21 patients. N20–P25 amplitudes were significantly higher in patients who recovered consciousness than in those who died or did not recover consciousness at 6 months (median, 4.6 vs. 1.9 μV; P = 0.004) and 1 year (median, 4.6 vs. 2.1 μV; P = 0.02) after injury. The lowest N20–P25 amplitude in a patient who recovered consciousness was 2.15 μV. N20–P25 amplitudes correlated significantly with Coma Recovery Scale-Revised and Disability Rating Scale scores at 6 months and 1 year post-injury (both P Conclusions In patients with VS/UWS, SEP amplitudes are related to consciousness recovery and disability at 6 months and 1 year post-injury. Significance The evaluation of SEP amplitudes can help to refine prognoses for patients with VS/UWS.