From Skin to Sinus: A Rare Case of Cerebral Venous Sinus Thrombosis Caused by Occipital Subcutaneous Abscess.

Infectious cerebral venous sinus thrombosis (CVST) typically arises from contiguous infections such as sinusitis or otitis media; however, CVST secondary to a subcutaneous abscess is exceedingly rare. We report the case of a 68-year-old woman who presented with a fever, headache, and a painful occipital scalp mass. Initial imaging identified a subcutaneous abscess in the occipital region, and subsequent magnetic resonance imaging (MRI) revealed thrombosis involving the superior sagittal, transverse, and sigmoid sinuses. Methicillin-sensitive Staphylococcus aureus (MSSA) was isolated from both blood and abscess cultures. Anticoagulation and intravenous antibiotic therapy were promptly initiated. Diplopia developed on day 10 of illness, was closely monitored through serial neurological examinations, and gradually resolved over the ensuing months, with complete resolution noted at the six-month follow-up. Follow-up imaging at 24 months demonstrated partial recanalization of the affected venous sinuses. This case underscores a rare but critical progression from a localized scalp infection to CVST. Clinicians should maintain a high index of suspicion in patients presenting with occipital scalp infections accompanied by neurological symptoms. To our knowledge, this is one of the few reported cases of CVST arising from a posterior scalp abscess, expanding the spectrum of infectious sources and guiding management strategies in similar presentations.