Primary Pyogenic Ventriculitis in Adults: A Retrospective Case Series of Clinical Characteristics, Cerebrospinal Fluid Parameters, and Surgical Drain Managements

Background/Objectives: Primary pyogenic ventriculitis in adults is a rare, life-threatening central nervous system infection occurring in the absence of prior neurosurgical interventions or indwelling medical devices. Due to its scarcity, individual clinical trajectories, cerebrospinal fluid (CSF) cytochemical variations, and external ventricular drain (EVD) management timing remain poorly defined. Methods: We conducted a retrospective case series of N = 8 with confirmed primary pyogenic ventriculitis admitted to a tertiary referral center in eastern Taiwan between 2019 and 2023. Individual-level clinical, neuroimaging, CSF, and surgical timing data were analyzed descriptively. Results: The cohort was 62.5% male (n = 5/8) with a median age of 60.5 years [IQR: 51.5–66.5]. All patients presented with severe initial neurological impairment (median initial Glasgow Coma Scale [GCS] = 7.5 [IQR: 4.0–9.75]). Overall 1-year mortality was 25.0% (n = 2/8, both male). Survivors (n = 6) exhibited marked initial CSF pleocytosis (median WBC = 1005.0 cells/µL [IQR: 508.0–1977.5]) and elevated protein (median = 1030.0 mg/dL [IQR: 847.5–1225.0]). Conversely, non-survivors (n = 2) demonstrated blunted initial CSF inflammatory markers (median WBC = 82.5 cells/µL; median protein = 212.1 mg/dL) alongside severe initial coma (median GCS = 3.5) and systemic shock requiring vasopressors. EVD placement occurred at a median of 2.5 days post-onset in non-survivors compared to 10.5 days in survivors, reflecting urgent, reactive surgical intervention in rapidly deteriorating cases (confounding by indication). At 1 year, surviving patients achieved a median modified Rankin Scale (mRS) score of 2.5 [IQR: 2.0–3.0]. Conclusions: In this rare adult primary pyogenic ventriculitis series, fatal cases were characterized by severe initial coma, vasopressor-dependent shock, and blunted CSF cellularity. Urgent EVD placement in non-survivors represented reactive rescue therapy. Future prospective multicenter registries are required to evaluate whether standardized, early intraventricular source control improves functional outcomes.