|The recent 2012 outbreak of fungal mengitis caused by tainted steroid injections has focused attention on fungal infections of the brain and other nerves. As of October 23, 2012 at least 18 people have died and 283 more made sick due to fungal brain infections caused by US steroid injections tainted with Aspergillus niger fungi.|
Fungal (mold) infections to the brain were once relatively rare. Now they are becoming increasingly more common for many reasons including: 1) increases in the number of HIV/ AIDS patients, 2) increases in the number of patients with certain cancers like leukemia or lymphoma, 3) increases in patients on immunosuppressive therapy for organ or bone marrow transplants, and 4) increased numbers of patients on long term antibiotic therapy which can encourage mold overgrowth. The most common fungi to cause brain infections include filament-forming fungi like Aspergillus, Mucor and Rhizopus and yeast-type fungi such as Candida and Cryptococcus. Less common causes of fungal brain infections include Trichosporon, Blastomyces, Histoplasma, Coccidioides, Paracoccidioides and Penicillium marneffei.
The most common form of fungal brain infections are meningitis, although these infections cause also present as localized brain infections called abscesses.
Meningitis typically presents with fever, headache, eye problems, difficulty concentrating and seizures. Brain abscesses can present with a local brain defect- such as a localized seizure. Even with hospital treatment, fungal meningitis and abscesses cam have a high mortality rate of over 20%.
Fungal brain infections may be hard to detect at their early and highly treatable stages. Testing the blood for galactomannan or for mold cultures may detect some fungal brain infections. Lumbar puncture and brain imaging may also be useful in some cases.
Drug treatment of fungal brain infections is complicated by the fact that many common antifungal drugs do not easily cross the blood-brain barrier. Some successes in treating fungal brain infections has been reported with the use of Amphotericin B, and some of the azole drugs such as Voriconazole and Posconazole. The newer Echinocandin drugs such as Caspofungin and Micafungin are very effective in treating brain infections caused by such fungi as Aspergillus and Candida, however they do not have good activity against some other fungi such as Cryptococcus, Mucor or Rhizopus.
Eileen Scully et al. Fungal brain infections. Current Opinion Neurology 2008;21:347-352.