Hi,
The transverse and sigmoid sinuses are venous sinuses within the brain.Your mom appears to have had a cerebral venous thrombosis.This apparently differs from a stroke which involves the arterial vessels and thus gives more evident neurologic deficits as its symptoms.
Venous thrombosis is usually managed using anticoagulants.Your mom is currently using coumadin.You noted that her headaches persist despite of the medications.I suggest that she maintains close follow up with her physician. The symptoms of venous thrombosis may sometimes present subtly and are nonspecific.Some patients may respond with the anticoagulant therapy while in some ,the symptoms may progress and may require more invasive and surgical interventions.
Has your mom's coagulation factors been assessed? Was a complete cardiac assessment done? Determining fibrinogen,Protein C and Protein S levels may be able to help.These are proteins responsible for regulating blood clotting mechanisms in the body.
Do dicuss your concerns with your mom's physicians.Close supervision is necessary in her case.
Unfortunately I don't know really about blood clots... only that there is medication out there that is suppose to get rid of them. I have a question though... how did they find out she had a blood clot in her head? I have been dealing with the same type of pain....