There are space-occupying intracranial infectious lesions causing headache other than brain abscess or subdural empyema. Since the pathophysiology is miscellaneous and the systematic studies to classify these headaches are inadequate, tentative diagnostic criteria are given here in the appendix.
- Headache with at least one of the following characteristics and fulfilling criteria C and D:
- diffuse continuous pain
- aggravated by straining
- accompanied by nausea and/or focal neurological symptoms and/or signs
- Evidence of a space-occupying intracranial infectious lesion or infestation from neuroimaging and/or laboratory investigations
- Headache develops during the space-occupying intracranial infection or infestation
- Headache resolves within 3 months1 after successful treatment of the lesion
- Headache usually resolves within 1 month.
A direct space-occupying effect leading to raised intracranial pressure and/or irritation of the meningeal or arterial structures are the mechanisms for causing headache of this subtype.
The most common organisms causing space occupying granulomatous or cystic central nervous system diseases are mycobacteria, fungi (eg, Cryptococcus neoformans and others), Toxoplasma gondii, free living amoebae, cestodes (eg, Cysticercus cellulosae, Coenurus cerebralis, Sparganum species), nematodes (eg, Toxocara canis, lymphatic filariae, Onchocerca volvulus, Anisakis species) and trematodes (eg, Schistosoma species, in particular Schistosoma japonicum, and Paragonimus species).