Subtentorial subdural empyema; report of two cases and review of the literatures

Escherichia colipositive infratentorial subdural empyema secondary to mastoiditis and underlying cholesteatoma

“…The majority of infratentorial subdural empyemas are as a result of neglected otogenic causes, as was the case in our patient, but other causes such as bacterial meningitis, paranasal sinus disease, head trauma or haematogenous dissemination of systemic infection have been implicated 5–7. Acute mastoiditis is especially implicated with posterior fossa empyema in the infratentorial location due to osseous destruction in the Trautmann triangle over the sigmoid sinus plate or in the posterior cortex of the petrous pyramid 8.…”

“…However, failure to demonstrate infratentorial empyema with CT has been reported previously, a limitation attributed to partial volume averaging effects and scanning artefacts due to the complex posterior fossa osseous architecture 5 9. MRI with diffusion-weighted imaging (DWI) is the preferred imaging modality for detecting infratentorially located empyema, owing to its multiplanar capabilities, improved soft tissue imaging and the absence of scanning artefacts related to the osseous skull base 12 13…”

“…Cases where conservative management has been successfully deployed in patients with normal GCS, no focal neurological deficits and limited abscess collection on imaging have been reported in the literature. However, this carries with it the disadvantage of not knowing the infective microorganism, the requirement of a prolonged course of empirical antibiotics and the potential of a relapse if the initial treatment was successful 5 15…”

Infratentorial subdural empyemas mimicking pyogenic meningitis

“…Subdural empyemas are a well-known complication of cranial sepsis which are more common in the pediatric age group with the mean age of presentation being 12-16 years of age. [1,2] However, in its most common presentation, the condition mimics a simple pyogenic meningitis [1][2][3][4][5] and is more likely to present to a general practitioner or pediatrician than a neuro-specialist.…”

“…[6] The condition commonly presents with features of meningitis, in a patient with history of chronic ear discharge. [1][2][3][4][5] Only about 25% of all cases have focal neurological signs, [4] or features of raised intracranial tension. Deaths have been reported following lumbar punctures.…”