Infratentorial subdural empyemas mimicking pyogenic meningitis

Abstract

Infratentorial subdural empyema is an extremely rare condition which unfortunately mimics pyogenic meningitis in 75% of cases. While an ill-planned lumbar puncture in these cases may be fatal, an inadvertent delay in treatment may be detrimental to the outcome for the patient. We present a case of a young boy with long standing history of chronic suppurative otitis media (CSOM) presenting with an infratentorial empyema with features suggestive of pyogenic meningitis. We also review the available literature to further define the condition in terms of clinical features, treatment options, and outcome. A misdiagnosis of this condition with failure to institute appropriate surgical intervention and antibiotic therapy is potentially life threatening. We highlight this rare condition which requires a high degree of suspicion especially in the presence of associated risk factors.

Keywords: Masquerading; meningitis; pyogenic; subdural empyemas.

Figure 1

Plain and contrast MRI of the posterior fossa showing a well defined loculated collection in the right subtentorial plain. The collection appears hypointense on T1-weighted images and hyperintense on T2-weighted images, with peripheral contrast enhancement. There is no associated hydrocephalus. Supratentorial compartment was normal

Figure 2

Plain and contrast CT head images showing hypodense collection with peripheral contrast enhancement which has increased in size compared to the MRI and is causing compression and distortion of the 4^th ventricle with obstructive hydrocephalus