Refractory Cavernous Sinus Thrombophlebitis Complicated by Brain Abscess and Infectious Hydrocephalus: A Case Report

Background: Cavernous sinus thrombophlebitis (CST) is a rare, life-threatening infection with high morbidity. Its management becomes exceptionally challenging when complicated by intracranial abscesses, hydrocephalus, and multidrug-resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). Case presentation: We report a case of a 52-year-old woman with poorly controlled diabetes and chronic alcohol use, who presented with headache, fever, and ocular symptoms. Initial neuroimaging suggested sinusitis and ischemic lesions. Metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) detected Staphylococcus aureus. Despite comprehensive antimicrobial therapy (including meropenem, vancomycin, and linezolid), anti-inflammatory treatment, and anticoagulation, her clinical course deteriorated with the development of brain and lung abscesses, cerebral infarction, and obstructive hydrocephalus. Serial CSF cultures grew MRSA alongside other organisms (Pantoea agglomerans, MRSE, Streptococcus salivarius). Multidisciplinary management led to external ventricular drainage and, ultimately, intraventricular vancomycin administration via an Ommaya reservoir, which achieved CSF sterilization. A ventriculoperitoneal shunt was subsequently placed, with sustained clinical improvement. Conclusions: This case illustrates the severe and refractory nature of MRSA-associated CST with intracranial complications. It highlights the diagnostic challenges posed by atypical presentations and polymicrobial infections, and underscores the critical limitations of systemic antibiotics in penetrating the central nervous system. The successful outcome was contingent upon a proactive, multidisciplinary strategy that included timely surgical intervention and the strategic use of intraventricular antimicrobial therapy to overcome the blood-brain barrier. This report emphasizes the importance of dynamic monitoring, personalized treatment escalation, and integrated team-based care in managing such complex infections.