Figure 2: Repositioning of the recording subdural strip electrode with improvement of the morphology and amplitudes of the recorded cortical SSEPs as well as of their phase reversal. Panel A shows recording via a strip placed as shown in the picture. Contact 1 of the strip is the most posterior. No reliable SSEPs are recorded. Panel B shows SSEPs recordings after re-orentation of the strip, as shown by the arrow, in panel A. A clear phase reversal is seen between contacts 3 (postcentral) and 4 (precentral). Notice the new strip position. The sulcus seen between contacts 3 and 4 is identified as CS.