Pneumocephalus in neonatal meningitis: Diffuse, necrotizing meningo-encephalitis in Citrobacter meningitis presenting with pneumatosis oculi and pneumocephalus

Abstract
Gas-containing encephalitis is rarely associated with neonatal meningitis. We report a case of a 19-day-old baby who presented with a rapid onset of septic shock complicated by progressively increasing gas accumulation within the brain and anterior chamber of the eye. We describe the evolution of the clinical picture and the management. Ventilatory support, fluid resuscitation, and continuous venovenous hemofiltration were provided in view of multiple system failure. Despite effective antibiotic therapy and supportive management, the patient died with worsening accumulation of gas within the brain, resulting in brainstem death. Computed tomographic images were characteristic of diffuse necrotizing meningo-encephalitis. Postmortem examination showed friable brain tissue with venous infarction and extensive gas accumulation. Citrobacter koseri was identified from the blood and cerebrospinal fluid cultures. This case re-emphasises the importance of C. koseri as both a community-acquired and nosocomial neonatal pathogen. Radiologic evidence suggestive of diffuse necrotizing meningo-encephalitis in combination with pneumocephalus and pneumatosis oculi in Citrobacter infections has never been described before. Diagnostic imaging with computed tomographic scanning of the brain and initiation of broad-spectrum antibiotics with good penetration into cerebrospinal fluid are indicated as soon as infection with Citrobacter species is suspected clinically, with appearance of pneumatosis oculi as a rare, late finding.