Thyroid dysfunction in cerebral venous thrombosis: a retrospective cohort study.

Background: Cerebral venous thrombosis (CVT) is a multifactorial disease with a variety of related conditions and risk factors. Thyroid dysfunction-especially hyperthyroidism-has been linked to CVT, but this is mainly based on case reports ranging back to 1913, while systematic investigations addressing this issue are lacking. Therefore, we investigated the frequency and clinical characteristics of thyroid dysfunction in a large single-center cohort of CVT patients.

Methods: We retrospectively identified all consecutive patients with aseptic CVT treated at our center between 2006 and 2020. Clinical information was extracted from our electronic medical documentation system. Thyroid-stimulating hormone (TSH) had been routinely measured at admission, free thyroid hormones and thyroid autoantibodies were analyzed whenever available.

Results: Of 120 patients with imaging-confirmed CVT, our main analysis included 107 patients (mean age 42 ± 16 years, 74% female) in whom TSH measurements were available. Nineteen patients (17.8%, 95% confidence interval 10-25%) had thyroid dysfunction. Two had newly diagnosed hyperthyroidism (1.9%, 95% confidence interval 0-4%) caused by Graves' disease, but without typical symptoms for this condition. Seventeen patients (15.9%, 95% confidence interval 9-23%) had hypothyroidism (12 previously diagnosed with ongoing thyroid hormone replacement therapy; 5 with newly diagnosed subclinical hypothyroidism). Clinical CVT characteristics were similar comparing patients with versus without thyroid dysfunction.

Conclusion: We observed a remarkably high prevalence of thyroid dysfunction in CVT patients. Whether this finding reflects a causal relationship warrants further studies. Despite that, the frequent coexistence of both diseases argues for TSH screening in CVT patients.