Subdural Empyema

A collection of pus within the subdural space, most commonly intracranial (complicating sinusitis, otitis media/mastoiditis, or, less commonly, meningitis or hematogenous spread) though spinal subdural empyema also occurs.

A neurosurgical emergency given rapid potential for mass effect, raised intracranial pressure, and venous thrombosis.

Fever, headache, and rapidly progressive focal neurological deficit (hemiparesis, aphasia), seizures, and declining consciousness, often with a preceding history of sinusitis or ear infection.

Signs of raised intracranial pressure can evolve rapidly.

Contrast-enhanced MRI (or CT if MRI unavailable) shows a crescentic, rim-enhancing collection.

Lumbar puncture is generally avoided given the mass effect and herniation risk; blood cultures and, where the primary source (sinus, ear) is accessible, culture of that source guide antibiotic choice.

• Urgent neurosurgical drainage (burr hole or craniotomy) is the mainstay, combined with empirical broad-spectrum IV antibiotics: a combination such as vancomycin plus a third-generation cephalosporin (ceftriaxone 2 g bd) plus metronidazole, covering staphylococci, streptococci, gram negatives, and anaerobes, given the frequent polymicrobial origin from sinus/ear sources
• Total antibiotic duration typically 4 to 6 weeks IV
• Anticonvulsants given the high seizure risk; management of raised intracranial pressure per general neurocritical care principles
• Treatment of the underlying source (sinus drainage, mastoidectomy) alongside the intracranial collection

Referral: neurosurgical emergency; ENT for source control of the primary sinus/ear infection.