Transsylvian Perspective of Insula with Cerebral Veins. The Sylvian fissure was completely dissected to permit full exposure of the insula. The optic nerve can be seen along the subfrontal corridor. The vein of Labbe and superficial middle cerebral vein are prominent and along the cerebral surface. The temporal lobe has been retracted from the middle cranial fossa. (Image courtesy of M Nunez)