Abnormal narrowing of transverse sinuses.

The transverse sinuses are a pair of dural venous sinuses that allow blood to drain from back the head.  The transverse sinuses drain the superior sagittal, occipital, and straight sinus and empties into the sigmoid sinus.  From there, the drainage goes to the jugular bulb.

When this narrowing occurs in the transverse sinuses, intracranial pressures increase and for those with connective tissue disorders, the likelihood of an aneurysm significantly increases.