What is the diagnosis and treatment for a 28-year-old female with cerebral venous sinus thrombosis of the transverse sinus, with a 4+ anisocytosis (ana) and low protein S level of 57, indicating protein S deficiency?

Differential Diagnosis for Cerebral Venous Sinus Thrombosis

Single Most Likely Diagnosis

• Antiphospholipid Syndrome (APS): Given the patient's age, sex, and the presence of cerebral venous sinus thrombosis (CVST) along with a significant antinuclear antibody (ANA) titer (4+), APS is a strong consideration. APS is known to cause venous thrombosis, including CVST, and is often associated with positive ANA.

Other Likely Diagnoses

• Protein S Deficiency: Although the protein S free level is 57, which might be considered within a normal range depending on the laboratory reference, the context of CVST warrants consideration of protein S deficiency, especially if the level is near the lower end of normal or if there are other risk factors for thrombosis.
• Oral Contraceptive Use: The patient's age and sex suggest the possibility of oral contraceptive use, which is a known risk factor for CVST.
• Nephrotic Syndrome: Although not directly indicated, nephrotic syndrome can lead to hypercoagulability and increase the risk of CVST. The proteinuria associated with nephrotic syndrome could potentially explain a low protein S level if it were significantly decreased.

Do Not Miss Diagnoses

• Cancer-Associated Thrombosis: Although less common, cancer can increase the risk of thrombosis, including CVST. A thorough evaluation for underlying malignancy is crucial, especially if other risk factors are not evident.
• Infectious Causes: Certain infections, such as mastoiditis or other parameningeal infections, can lead to CVST. Given the potential for severe consequences, infectious causes must be considered and ruled out.
• Trauma: Head trauma can cause CVST, either directly or through dehydration and subsequent hypercoagulability.

Rare Diagnoses

• Pregnancy-Related CVST: Although the patient's pregnancy status is not mentioned, pregnancy and the postpartum period are known risk factors for CVST.
• Behçet's Disease: This rare condition can cause CVST among other symptoms. It would be considered if there were additional symptoms such as oral or genital ulcers, or uveitis.
• Homocystinuria: A genetic disorder that affects the metabolism of the amino acid methionine, leading to elevated homocysteine levels, which can increase the risk of thrombosis, including CVST.
• Factor V Leiden or Other Thrombophilic Mutations: While more commonly associated with arterial thrombosis, these mutations can also increase the risk of venous thrombosis, including CVST, especially in the presence of other risk factors.