Axial T1 post-contrast MRI. Demonstrates Leptomeningeal enhancement and a chronic meningitic infarct.
Meningoencephalitis: Fungal
Overview
- Chronic (smoldering symptoms)
- Vasculitic (with vascular invasion)
- Parenchymal invasive (aka granulomatous) (which invade the brain matter).
- < 10 cells, 70% of which are lymphocytes
- Glucose is 60% of that of the serum glucose
- Protein is from 15 to 45
- CSF pressure is usually 70 to 180 mmH2O.
- Cell counts are typically from 50 to 250, the majority of cells are usually lymphocytes (like in viral)
- Glucose is low (like it is in bacterial)
- Protein is elevated
- Intracranial pressure is variable, depending on the degree of CSF obstruction
Fungal encephalitis Details
Chronic
We differentiate the key chronic fungal encephilitides on demographics
- Histoplasmosis mostly exists in the Mississippi and Ohio river valleys from Bird and Bat droppings.
- On pathology, it's found in macrophages.
- Coccidioides exists in the Southwestern US (so-called "San Joaquin fever").
- Notably it manifests with "desert bumps" for erythema nodosum and desert rheumatism for arthralgias.
- Blastomycosis exists in the Eastern U.S.
- On pathology, there is characteristic broad-based budding.
Vasculitic
- Mucormycosis, which proliferates in the blood vessel walls in the setting of excess ketones and glucose (so, notably, in poorly controlled diabetics).
- Aspergillosis, which forms aspergillomas in lung cavities and allergic bronchopulmonary aspergillosis (notably occurs in asthmatics and cystic fibrosis).
Parenchymal Invasion
- Candida forms microabscesses in disseminated candidiasis (which occurs in the immunocompromised, most notably).
- Cryptococcus forms characteristic soap-bubble lesions visualizable on radiographic imaging from the gelatinous pseudocysts that dilate Virchow-Robin.