# Paradoxical Worsening of Cerebral Venous Sinus Thrombosis Due to Heparin-Induced Thrombocytopenia: A Case Report and Literature Review

## TL;DR

A woman's cerebral venous sinus thrombosis worsened after heparin treatment due to a rare immune reaction called heparin-induced thrombocytopenia.

## Contribution

This case highlights the rare but critical paradoxical worsening of CVST due to HIT during heparin therapy.

## Key findings

- Heparin treatment for CVST led to HIT, causing a paradoxical worsening of the condition.
- Tonic convulsive seizures were the first sign of HIT development in this patient.
- Discontinuing heparin and using argatroban improved the patient's condition.

## Abstract

Development of cerebral venous sinus thrombosis (CVST) is a rare manifestation of heparin-induced thrombocytopenia (HIT). Herein, we present a case in which heparin administration for primary CVST caused paradoxical worsening of CVST secondary to HIT. A 53-year-old woman diagnosed with CVST was provided with intravenous unfractionated heparin therapy. After 12 days, the patient presented tonic convulsive seizures (TCS). Subsequent magnetic resonance image (MRI) scans revealed an exacerbation of cerebral edema with a subcortical hemorrhage on the left parietal lobe. Laboratory test results revealed a significant decline in platelet count. Heparin was immediately discontinued and replaced with argatroban. The definitive diagnosis of HIT was made through the presence of HIT antibodies. The present case, in which HIT caused the secondary CVST exacerbation, is distinctly rare. Our case provides an instructive example by highlighting the potential of TCS as the first sign of HIT development during CVST treatment.