9.1.4 Headache attributed to localized brain infection


Headache caused by brain abscess, subdural empyema, infectious granuloma or other localized infective lesion, usually associated with fever, focal neurological deficit(s) and/or altered mental state (including impaired vigilance).

Diagnostic criteria:
  1. Any headache fulfilling criterion C
  2. A localized brain infection has been demonstrated by neuroimaging and/or specimen analysis
  3. Evidence of causation demonstrated by at least two of the following:
    1. headache has developed in temporal relation to development of the localized brain infection, or led to its discovery
    2. headache has significantly worsened in parallel with deterioration of the localized brain infection shown by either of the following:
      • a) worsening of other symptoms and/or clinical signs arising from the localized brain infection
      • b) evidence of enlargement (or rupture, in the case of brain abscess) of the localized brain infection
    3. headache has significantly improved in parallel with improvement in the localized brain infection
    4. headache has at least one of the following characteristics:
      • a) intensity increasing gradually, over several hours or days, to moderate or severe
      • b) aggravated by straining or other Valsalva manœuvre
      • c) accompanied by fever, nausea and/or vomiting
      • d) unilateral, and ipsilateral to the localized brain infection
  4. Not better accounted for by another ICHD-3 diagnosis.

Brain abscesses are usually caused by anaerobic or, sometimes, mixed bacteria, often including anaerobic streptococci or bacteroides. Staphylococci are common after cranial trauma, neurosurgery, or endocarditis. Enterobacteria are common in chronic ear infections. Fungi (eg, aspergillus) and protozoa (eg, Toxoplasma gondii, particularly in HIV-infected patients) can cause abscesses.

Subdural empyema is often secondary to sinusitis or otitis media. It may also be a complication of meningitis.

Brain granulomas have been associated with cystercosis, sarcoidosis, toxoplasmosis and aspergillosis.

The mechanisms causing 9.1.4 Headache attributed to localized brain infection include direct compression, irritation of the meningeal and/or arterial structures, increased intracranial pressure and fever. Headache attributed to subdural empyema is particularly associated with fever and symptoms and/or clinical signs of meningeal irritation and increased intracranial pressure.