Fig. 1.

Schematic depictions of superficial middle cerebral vein (SMCV) drainage patterns. (A) Undeveloped type: the SMCV is absent. (B) Sphenoparietal sinus type: the SMCV enters the CS through the sphenoparietal sinus. (C) Cavernous capture type: the SMCV enters the anterior end of the CS directly. (D) Emissary type: the SMCV courses along the lesser wing and turns inferiorly to reach the pterygoid plexus through the middle cranial fossa basal foramen. (E) Basal type: the SMCV runs along the Sylvian fissure, turns downward posteriorly along the middle cranial fossa, and runs along its floor lateral to the foramen ovale to join the transverse sinus. (F) Superior petrosal type: the SMCV runs along the lesser wing, turns downward posteriorly without connecting with the sphenoparietal sinus or CS, runs along the middle of the cranial floor medial to the foramen ovale and lateral to the CS, and joins the SPS. (G) Squamosal type: the SMCV turns directly backward along the inner aspect of the temporal squama without turning medially to connect with the sinus and runs posteriorly to connect with the transverse sinus or lateral tentorial sinus. (H) Combined type: the SMCV is composed of a combination of any of the above types.