Sagittal Sinus Thrombosis - Symptoms and Treatment

Introduction

Superior sagittal sinus thrombosis is believed to be a reason causing a stroke. Age groups between 37 to 40 are at the main risk, although any age can be affected, irrespective of male or female. In females, it can occur due to the use of contraceptive pills or due to the postpartum state. The symptoms of this condition can be varied and can range from mild headaches, including vomiting and seizures. The variation in the symptoms can cause a huge challenge in obtaining a diagnosis for the physician. This article explains the detailed symptoms and the treatment modalities that are available for treating superior sagittal sinus thrombosis.

What Is Sagittal Sinus?

The sagittal sinus, called the superior sagittal sinus, is a venous structure present in the brain region. It is the largest sinus of dural venous sinuses. It is located at the sagittal suture. Any surgery that is required to be done at the sagittal suture needs a computed tomography scan (CT scan), or magnetic resonance imaging (MRI) is advised to carry out the surgery. The main function of the sagittal sinus is to drain the anterior cerebral hemispheres of the brain. Not only draining the blood, but it also has an important role in CSF (cerebrospinal fluid) hemostasis along with receiving blood from veins of the scalp.

What Is Sagittal Sinus Thrombosis?

The commonly occurring pathology of the sagittal sinus is thrombosis. Thrombosis occurs due to blood clots in the blood vessels. Such thrombosis occurring in the sagittal sinus is termed sagittal sinus thrombosis. Thrombosis of the sagittal sinus is of extreme importance due to the consequences that occur after the issue. Due to the blockage of the veins, the drainage is interrupted, leading to increased pressure in the cranium along with edema in the obstructed veins.

What Are the Clinical Conditions of Sagittal Sinus Thrombosis?

Sagittal sinus thrombosis can range from associated symptoms as well as being asymptomatic. The symptoms can gradually develop and increase in intensity and can also lead to death. Following are the clinical symptoms.

• Headache.

• Paralysis.

• Disturbances in the vision.

• Papilledema (swelling of optic discs).

• Seizures.

• Nausea.

• Stroke.

What Are the Diagnostic Methods of Sagittal Sinus Thrombosis?

Primarily, imaging modalities used in the evaluation of venous sinus thrombosis include

1. Magnetic resonance imaging (MRI).

2. Computed tomogram venography.

3. Laboratory tests.

• Magnetic Resonance Imaging (MRI) -

The least sensitive and specific imaging test is magnetic resonance imaging. Sagittal sinus thrombosis often presents with many neurologic symptoms, such as mental illness or elevation of intracranial pressure. All these conditions lead the way to getting an MRI done. Detection of the thrombosis and certain findings, such as the period of occurrence of a clot (age of the clot) and the stage of the clot is also important.

• Computed Tomogram Venography -

Computed tomogram (CT) venography or magnetic resonance venography are more specific and sensitive diagnostic modalities for imaging the sagittal sinus. CT venography, contrast-enhanced venography, and MR venography are all imaging techniques that show the presence of any thrombus. Non-contrast enhanced head CT shows the presence of common signs as hyper-density present within the sinus. This happens due to the dense blood flowing in the thrombus more than the normal flowing blood. The absoluteness of the test is a little low compared to other imaging techniques. A cord sign is also present which occurs due to the increase in the density of the vein, which has a cord-like appearance. The inclusion of contrast in the CT venography aids in the visualization of the thrombus. Another sign termed an empty delta sign is also visible because the thrombus appears darker as the filling defect. The lack of blood flow is seen in 3D visualization.

• Laboratory Tests -

Routine complete blood tests along with coagulation studies such as the following tests are performed.

• Prothrombin time.

• Activated partial thromboplastin time.

• International normalized ratio.

Patients with suspected venous thrombosis are advised by the blood tests mentioned. If there are no predisposing conditions, a proper medical history should be done to detect any underlying conditions. In the absence of any other condition, a workup for inherited thrombophilia or malignancy is considered. D-dimer values are looked up to indicate the presence of venous sinus thrombosis.

What Are the Risk Factors Associated With Sagittal Sinus Thrombosis?

Following are the risk factors associated with sagittal sinus thrombosis.

• Dehydration.

• Pregnancy.

• Malignancy.

• Estrogen replacement therapy (a hormone therapy that relieves symptoms related to defective reproductive health)

• Prothrombotic conditions (conditions predisposing to thrombosis such as certain liver diseases, heart diseases, and pregnancies).

What Are the Risks Associated With Sagittal Sinus Thrombosis?

Following are the risks and complications associated with sagittal sinus thrombosis.

• Septic thrombosis (thrombosis in a vein leading to infection).

• Dysregulation of the CNS drainage pathway.

• Cerebral herniation (shift of tissue in the cerebrum to another region).

• Development of meningiomas (tumors of the meninges - the membranes surrounding the brain and spinal cord).

• Intracranial hemorrhage (bleeding within the cranium).

• Arteriovenous fistulas (an abnormal connection between artery and vein).

What Is the Treatment for Sagittal Sinus Thrombosis?

• The first line of treatment for sinus thrombosis includes the administration of systemic anticoagulants such as Heparin and Warfarin. The setting of venous hemorrhages also requires anticoagulation. Thromboplastin or microcatheter thrombolysis is included in interventional management. Venous infarctions are also set by heparin. The symptoms of the clinical condition can be variable depending on the intensity of the condition.

• Targeted thrombolytics are used in the affected sinuses to perform catheter-directed thrombolysis by experienced neuroradiologists

• The presence of hemorrhagic venous infarcts, coma, and co-existing malignancies can predispose to poor treatment outcomes.

• Deep cerebral venous thrombosis also brings down the prognosis due to the large area of involvement in the brain.

Conclusion

Sagittal sinus thrombosis is an extremely challenging condition as its clinical symptoms are highly variable, and diagnosis of the condition should be made very accurately to opt for the right treatment. The complications coming along with the condition are many that can even be fatal or life-threatening. Advanced diagnostic images like neuroimaging help in the diagnosis of the condition although underlying causative agents and conditions are absent. An experienced neuro-physician should be consulted right when the symptoms appear instead of letting them worsen.