Teaching Case

Acute neurologic deterioration

The patient presented with acute neurologic deterioration with nonspecific clinical signs and symptoms. A CT scan was normal, and the patient was referred to MRI two days later. On MRI an impression of high signal was noted in the anterior portions of superior sagittal sinus. MR angiography, and diffusion MRI were obtained.

Venous sinus thrombosis most commonly involves the superior sagittal sinus, and can result in petechial hemorrhages and venous infacts. A variety of disease processes including dehydratation, infection, trauma, hematologic disorders, and others may cause venous sinus thrombosis. In some cases, however, no cause can be identified. In cases with prominent changes associated with venous sinus thrombosis, an empty delta sign on CT, and an hyperintense sinus are usually noted in the subacute phase. In the acute phase, however, a CT scan may be normal, and changes on MRI may be equivocal. Complications (petechial hemorrhages and venous infacts) are best identified on MRI. MR angiography can reveal occluded parts of the sinus. On diffusion MRI venous infarcts are usually well demonstrated. Apparent diffusion coefficient (ADC) maps can reveal the thrombus itself, as well as associated changes as demonstrated in the current case. The cause of thrombosis was unclear in this patient. The clinical outcome was good with thrombolytic therapy.