Brain abscess

Article section 1 of 16.  Next

By John E Greenlee MD

Brain abscess is an important complication of both systemic and pericranial infections (sinusitis, otitis, etc.), of cranial trauma, and of neurosurgical procedures. The disorder is highly treatable – at times with antibiotics – if diagnosed early in its course. If misdiagnosed, however, it may cause severe neurologic injury or death. In this review, Dr. John Greenlee, Professor of Neurology at the University of Utah School of Medicine and neurologist at the George E. Wahlen Veterans Affairs Medical Center in Salt Lake City, Utah, discusses the pathogenesis and clinical presentation of brain abscess and provides an approach to diagnosis and treatment of the disorder.

Key points

  • Brain abscess most commonly arises by hematogenous spread. Less frequently, it may occur as a complication of sinusitis, otitis, mastoiditis, or penetrating trauma. Brain abscess may be caused by a single agent, but it may also be polymicrobial.
  • The classic presentation of brain abscess is headache, fever, and focal neurologic signs. In most patients, however, this triad is not found, and presentation is that of a subacutely developing intracerebral mass lesion. Rapid deterioration may follow intraventricular rupture.
  • The diagnostic procedure of choice for brain abscess is contrast-enhanced MRI. CT scan with contrast, although useful, is less sensitive.
  • Treatment of brain abscess, in the great majority of patients, consists of antibiotic therapy and drainage. Until identification of the causative organism(s), initial antibiotic therapy should be directed against Staphylococcus aureus and other potential Gram-positive agents, Gram-negative agents, and anaerobes.
  • Occasionally, small abscesses may respond to antibiotics alone. Patients being treated with antibiotics alone, however, need to be followed carefully by clinical examination and MRI to detect enlargement of the abscess in the face of antibiotic treatment.