Anaerobic Infections, Central Nervous System

Key Features

• Common cause of brain abscess, subdural empyema, or septic CNS thrombophlebitis

• The organisms reach CNS by direct extension from sinusitis, otitis, or mastoiditis or by hematogenous spread from chronic lung infections

Clinical Findings

• Various neurologic deficits

Diagnosis

• MRI scan (most sensitive) or CT scan

• Culture of infected tissue

Treatment

• Antimicrobial therapy is an important adjunct to surgical drainage

  • Ceftriaxone, 2 g intravenously every 12 hours, plus metronidazole, 500 mg intravenously every 8 hours

• Duration of antibiotic therapy is 6–8 weeks but should be based on follow-up imaging

• Some small multiple brain abscesses can be treated with antibiotics alone without surgical drainage