Refractory cavernous sinus thrombophlebitis complicated by brain abscess and infectious hydrocephalus: a case report and literature review

Cavernous sinus thrombophlebitis (CST) is a rare, life-threatening infection. Its management becomes exceptionally challenging when complicated by intracranial abscesses, hydrocephalus, and multidrug-resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). A 52-year-old woman with poorly controlled diabetes presented with headache, eye pain, diplopia, fever, and progressive ocular symptoms. Outpatient ceftriaxone and subsequent ertapenem were ineffective. Neuroimaging confirmed CST with early brain abscess formation. Despite systemic antimicrobial therapy (meropenem, vancomycin, linezolid) and anticoagulation, she developed cerebral infarction, hydrocephalus requiring Ommaya reservoir placement, and persistent positive cerebrospinal fluid (CSF) cultures for MRSA and other organisms. Following multidisciplinary team (MDT) review involving infectious diseases, neurosurgery, ophthalmology, and otorhinolaryngology, intraventricular vancomycin (15 mg daily) was administered via an external ventricular drain, achieving CSF sterilization by day 79. A ventriculoperitoneal shunt was subsequently placed with sustained clinical improvement. This refractory MRSA-associated CST case illustrates the critical limitations of systemic antibiotics in penetrating the central nervous system. Successful outcome depended on: (1) early recognition in an at-risk host, (2) timely escalation to intraventricular therapy with a practical, evidence-based regimen, and (3) seamless MDT integration for diagnostic clarity and treatment sequencing. The detailed dosing and monitoring data provided here address a knowledge gap and offer a clinical template for managing similar complex CNS infections, with the potential for complete neurological recovery as demonstrated in this case.