Occlusion of a lateral sinus by an infected clot is encountered with diminishing frequency as compared with its common occurrence before the days of chemotherapy. Of great rarity is aspetic thrombosis of this venous channel secondary to cranial trauma.
When infection is present, the clinical picture is one of sepsis. If the clot is sterile, the patient can be asymptomatic.
In 90 per cent of specimens we examined, the lumen of the right lateral sinus was larger than the left. With such inequality, occlusion of the left sinus will not cause the same degree of intracranial hypertension as results from a right sided thrombus. When thrombosis of the right lateral sinus is present and a small left sinus exists, the mastoid, parietal, frontal and occipital emissary veins on the left are too small to carry the additional venous return. Papilledema, retinal hemorrhages and optic atrophy are important diagnostic findings. A