The superficial middle cerebral vein (SMCV), also known as the Sylvian vein, is one of the superficial cerebral veins. It usually courses along the Sylvian fissure posteroanteriorly and drains numerous small tributaries from the opercular areas around the lateral sulcus. It curves anteriorly around the tip of the temporal lobe and drains into the sphenoparietal sinus or directly into the cavernous sinus. There is however, significant variation (see below).

It may have connections to other dural venous sinuses by anastomotic veins:

• to the superior sagittal sinus by the superior anastomotic vein (of Trolard)
• to the transverse sinus by the inferior anastomotic vein (of Labbé)

Suzuki classification of the superficial Sylvian venous drainage pathways ¹  

1. sphenoparietal type: (54%) drains into the sphenoparietal sinus
2. emissary type: (12%) courses along the lesser wing of sphenoid, turns inferiorly to reach the floor of the middle cranial fossa, joins the sphenoidal emissary veins, and passes through the floor to reach the pterygoid plexus
3. cavernous type: (7%) directly drains into the anterior end of the cavernous sinus
4. superior petrosal type: (2%) runs along the lesser wing and just before reaching the cavernous sinus, turns downward along the anterior inner wall of the middle cranial fossa, then runs along its floor medially to the foramen ovale to join the superior petrosal sinus
5. basal type: (2%) runs along the lesser wing, turns downward along the anterior wall of the middle cranial fossa, then runs along its floor laterally to the foramen ovale over the petrous pyramid, presumably to join the transverse sinus through the lateral tentorial sinus or superior petrosal sinus
6. squamosal type: (2%) turns directly backward along the inner aspect of the temporal squama and runs posteriorly to join the transverse sinus or lateral tentorial sinus
7. undeveloped type: (9%) absent; superficial Sylvian drainage is through a large channel that extends forward, upward, upward and backward, or downward and backward into the superior sagittal sinus or transverse sinus