PROMISE (Somatosensory Evoked POtEntials MonItoring During Acute Ischemic StrokE) Study

We stimulate both median nerves at wrist by means of surface adhesive electrodes. We apply square wave electrical pulses of 0.2 ms duration at a frequency of 5.7Hz. SEPs are recorded in a referential fashion from the C3' and C4' positions and from a reference electrode at Fpz or Cz' electrodes(international 10-20 system) with needle electrodes. The target signal is the presence of N20 response ipsilateral to the stroke site and, if present, measure amplitude and latency comparing with the contralateral if present. SEPs are registered during the whole procedure.