Symptoms and Signs
Common symptoms and signs of CVST include headache, nausea, vomiting, seizure, and focal neurological deficit. Papilledema is present in 40% of cases, primarily in patients with delayed diagnosis or a chronic course.
Neurological Deficits
Cerebral venous sinus thrombosis may not necessarily cause focal neurological deficits due to numerous pathways of venous drainage and the possibility of reversal of venous blood flow. However, the condition can lead to impaired resorption of CSF causing intracranial hypertension.
Headache
In 70% of cases, headache is the initial symptom of CVST, and it is the only symptom in 16% of cases. With respect to headache presentation, it is important to remember that thunderclap headache is not exclusive to the diagnosis of subarachnoid hemorrhage (SAH). The absence of findings on workup to support the diagnosis of SAH should prompt investigation with MRV and evaluation of CVST.4
Seizure
Focal or generalized seizure on initial presentation occurs in 30% to 40% of cases of CVST. When smaller cerebral veins are involved, this can lead to focal edema, neurological deficits, venous infarction, and seizure. Focal deficits are determined by the localization of CVST and associated lesions. Other symptoms may include migraine headache, transient ischemic attack, cranial nerve palsies, and subarachnoid hemorrhage.4
Complications
Cerebral venous sinus thrombosis is a rare condition with an often varied clinical presentation—the symptoms of which can take hours to weeks to evolve, thus making the diagnosis challenging.
Complications in patients with CVST occur when venous congestion increases and raises dural venous sinus and cerebral spinal fluid (CSF) pressure. Parenchymal edema with venous infarction and hemorrhage complicates up to 50% of venous sinus thromboses (as seen in this patient).1 Unfortunately, little is known about long-term risk outcomes or recurrence of CVST.1
As previously noted, the patient presented with transient slurred speech, mild headache, and bilateral hand tingling. On workup, she was found to have an SSS thrombosis with an associated right intraparenchymal hemorrhage that occurred despite therapeutic INR levels and the initiation of coumadin therapy prior to admission.
Evaluation and Diagnosis
D-Dimer Evaluation
There is a strong association between D-dimer levels above 500 ng/mL and acute CVST. Nevertheless, lower levels do not rule out the diagnosis in a patient presenting with headache.4
Imaging Techniques
Important imaging techniques in the evaluation of CVST include CT, MRV, MRI, and magnetic resonance angiography (MRA). The first imaging modality in evaluating a patient with neurological symptoms and headache in the ED is CT, which can show evidence of an infarction that does not respond to an arterial distribution. In the absence of a hemorrhagic component, however, infarct demonstration may be delayed for up to 72 hours.5 On contrast CT, an empty delta sign may be apparent due to enhancement of the collateral veins in the SSS walls surrounding a nonenhanced thrombus. The delta sign is not frequently present and may be false due to early division of the SSS.5
Computed tomography venography, CT angiography, and MRI can also be utilized to evaluate for CVST. Computed tomography venography is especially useful in identifying the cerebral veins and dural sinuses,6 and MRV is an excellent method for visualizing the dural venous sinuses and larger cerebral veins. Single-slice phase-contrast angiography is also a rapid and reliable test for CVST.7 Conventional angiography and direct venography should be considered if MR studies are nondiagnostic; however, this test is invasive with associated risks.5
Treatment
Heparin therapy should be initiated in patients presenting with dural sinus thrombosis even if pre-existing hemorrhage exists. Patients failing to respond to therapy with worsening neurological deficits may warrant local thrombolysis with tissue plasminogen activator. Identifying those in the acute state of disease is essential as they may have poor prognostic outcomes that may warrant more invasive intervention.1
Conclusion
Cerebral venous sinus thrombosis is a rare condition with a diverse clinical presentation. As demonstrated in this case, some patients present with stroke-like symptoms of nontraumatic headache, slurred speech, and bilateral hand tingling, which, on workup, reveal SSS thrombosis associated right intraparenchymal hemorrhage.
This case draws attention to the importance of risk stratification in patients with a history of HCS and neurological complaints presenting to the ED. Dural sinus thrombosis may have a vague initial neurological presentation; therefore, early recognition and initiation of therapy will assist in reducing morbidity and mortality.
Dr Orlik is a resident, department of emergency medicine, Akron General Medical Center, Ohio. Mr Kovacs is a student and summer research fellow, department of emergency medicine, Akron General Medical Center, Ohio. Dr Simon is the emergency medicine research director, department of emergency medicine, Akron General Medical Center, Northeast Ohio Medical University.