The parasellar region from the transcranial approach. There are two triangles in the lateral wall of the cavernous sinus: supratrochlear and infratrochlear (Parkinson’s). The first division of the trigeminal nerve has been retracted inferiorly to expose the abducens nerve and the short ascending segment of the cavernous ICA, which are accessed through the infratrochlear triangle. (Image courtesy of JC Fernandez-Miranda)