Varicella Zoster Virus (VZV) primarily causes chickenpox, a common, highly contagious childhood illness characterised by a pruritic vesicular rash and systemic symptoms. While primary VZV infection in adults is less frequent due to childhood exposure, it tends to be more severe. It leads to complications such as pneumonia, hepatitis, and, rarely, neurological disorders.

Among these, cerebral venous sinus thrombosis (CVST) is an exceptionally rare but serious complication.

We report a case of a 38-year-old South Asian male who developed CVST following a recent primary VZV infection. The patient presented to the emergency department with a severe frontal headache that began three days prior without visual, speech, or balance disturbances.

The examination revealed crusted varicella lesions on the arms, trunk, and thighs. The neurological examination was unremarkable except for the severe headache. Cranial nerves were intact, with no evidence of objective weakness or loss of sensation.

Initial imaging with non-contrast head CT showed hyperdense bilateral transverse sinus thrombosis. A CT venogram confirmed extensive thrombosis in the left transverse and sigmoid sinuses. MRI and MRV supported these findings without evidence of acute infarction.

The pathogenesis of VZV-associated CVST involves endothelial damage, hypercoagulability, and vasculopathy, potentially induced by VZV's direct infection of cerebral vessels. This can lead to inflammation and thrombosis, contributing to the development of CVST in predisposed individuals. The patient was treated with enoxaparin, followed by long-term anticoagulation with warfarin, which resulted in symptom resolution. This case underscores the importance of recognising VZV as a potential cause of CVST, especially in adults presenting with severe headaches post-varicella infection. Early diagnosis and intervention are crucial to manage this rare but life-threatening complication effectively.

Ahmed Musa is currently a family medicine registrar in the United Kingdom. He is currently in the second year of training, aiming to complete by 2026 and focus more on the academic side of my career.