Meningitis due to Cryptococcus neoformans
Definition
Inflammation of the pia and arachnoid and spinal fluid associated with the fungus cryptococcus neoformans. The respiratory tract is the usual portal of entry and meningitis may occur after dissemination to the meninges from the lungs. C. neoformans meningitis tends to occur in patients with defective cellular immunity. The meningitis usually evolves subacutely, but may be acute. Clinical features include headache, fever, nausea and vomiting, meningismus, visual disturbances, abnormal mental status, seizures, and raised intracranial pressure. Headache, fever, and stiff neck may be absent. The diagnosis is made by microscopic examination of the spinal fluid, culture of CSF and blood, and the latex agglutination test to detect the capsular polysaccharide antigen in CSF and blood. The organism may be seen on Gram stain or India ink stain of the CSF. The spinal fluid usually shows varuable lymphocytic pleocytosis, a low glucose content, and a high protein level.