6.7:
Venous thrombosis
Venous
thrombosis as the cause of headache has received relatively little
attention. Classic presentation of cortical vein thrombosis is with
seizures and headache. There may be neurologic deficits depending upon
what venous areas are affected. For example, with sagittal sinus venous
thrombosis there may be an initial presentation of weakness in the legs
bilaterally, obtundation as intracranial pressure rises, and even
papilledema. Therapy in venous thrombosis is changing and many now
advocate anticoagulation. Considerable controversies still exist,
however, as to whether to anticoagulate in the face of a significant
hemorrhagic infarction.
The
causes of venous thrombosis predisposing conditions have been divided
into local and general categories by Bousser and Barnett (1988). Bousser
had divided the causes into local and general. Among the local causes
are direct septic trauma, intracranial infection, head injury, and
tumors. Among the general causes are bacterial septicemia, tuberculosis,
fungal infections, post-partum state, oral contraceptives, and
coagulation disorders. Headache was present in 80 percent of 76
patients. Papilledema was present in 50 percent, and focal motor or
sensory defects in 35 percent, and seizures in 29 percent. The classical
picture in superior sagittal sinus thrombosis is bilateral or
alternating deficits particularly in the lower limbs accompanied by
seizures. Some patients present with isolated intracranial hypertension
with headache, papilledema, and sixth nerve palsy mimicking benign
intracranial hypertension. This was present in 38 percent of Bousser and
Barnett’s patients.
A
cavernous sinus thrombosis syndrome including chemosis, proptosis, and
painful ophthalmoplegia, initially unilateral but frequently becoming
bilateral, is a classic distinctive clinical picture. Severe
complications can occur such as extension to other sinuses and stenosis
or thrombosis of the intracavernous portion of the internal carotid
artery. However, cavernous sinus thrombosis is not always acute and even
can take a more indolent form sometimes due to inadequate antibiotic
therapy present with an isolated abducens palsy with only mild chemosis
and proptosis leading to great diagnostic difficulty (Dinubile, 1988).
Venous thrombosis can present with isolated headache simulating a
post-lumbar puncture headache.
The
diagnosis of cerebral venous thrombosis may be suspected on the basis of
the clinical presentation such as headaches and seizures. CT scanning
may show a partially hemorrhagic infarction. Angiographic diagnosis of
isolated cortical vein thrombosis is extremely difficult. A CT scan
sign, the empty delta sign, (Buonanno et al, 1978) is the most frequent
direct sign of sagittal sinus thrombosis present in approximately 30
percent of cases. It appears after contrast injection and reflects the
opacification of collateral veins in this superior sagittal sinus wall
contrasting with the non-injection of the clot inside the sinus. MRI
offers major advantages for the evaluation of patients suspected of
having cerebral venous thrombosis because of its sensitivity to blood
flow and the ability to visualize the thrombus itself. These changes are
described elsewhere in detail (Bousser and Barnett, 1988).
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Other Headaches