Central nervous system blastomycosis diagnosed using the MVista® Blastomyces quantitative antigen enzyme immunoassay test on cerebrospinal fluid: A case report and review of the literature.

Blastomyces dermatitidis is a thermally dimorphic fungus that is capable of causing pulmonary and extra-pulmonary disease, including infections of the central nervous system (CNS). Diagnosis of CNS blastomycosis with non-invasive testing can be difficult, and a surgical biopsy may ultimately be required for microbiological and/or histopathological confirmation. A case of B. dermatitidis meningitis is presented where the diagnosis was made by testing cerebrospinal fluid (CSF) using the MVista® Blastomyces Quantitative Antigen Enzyme Immunoassay test. The utility of performing this test on CSF for diagnosis of CNS mass lesions/abscesses caused by B. dermatitidis in the absence of associated meningitis remains unclear. Cross reaction of the Blastomyces antigen test with other dimorphic fungi is a concern, necessitating that positive test results are interpreted in the context of the patient's exposure and travel history.

Meningoencephalitis due to Blastomyces dermatitidis: case report and literature review.

Infection of the central nervous system by Blastomyces dermatitidis is a rare cause of meningoencephalitis. The existence of exclusive clinical infection of the meninges in the absence of pulmonary or other foci of infection has been debated. We describe a 20-year-old man presenting with meningoencephalitis caused by B dermatitidis. Blastomycotic infection was confirmed by isolation of the organism from brain tissue obtained at biopsy. Magnetic resonance imaging demonstrated progressive enhancement of basal meninges with involvement of bilateral basal ganglia and thalami. Treatment with amphotericin B arrested further neurologic decline. However, clinical and radiographic follow-up suggested damage to diencephalic structures. The diagnosis of blastomycotic meningoencephalitis is difficult to establish because no sensitive serologic test exists, and attempts to isolate the organism in cerebrospinal fluid obtained by lumbar puncture generally fail. A biopsy specimen of brain tissue is frequently necessary for the diagnosis. Survival is possible with timely initiation of therapy.

Marked polymorphonuclear pleocytosis due to blastomycotic meningitis: case report and review.

Meningitis is an unusual manifestation of infection caused by Blastomyces dermatitidis. We describe a patient who presented with fulminant blastomycotic meningitis. Examination of the lumbar CSF demonstrated > 5,000 polymorphonuclear leukocytes/mm3. The diagnosis of B. dermatitidis meningitis was initially suggested by cytologic examination of CSF and confirmed by culture. Pleocytosis of this magnitude had not been previously described in association with blastomycosis, although review of the published literature revealed that neutrophilic pleocytosis is a common manifestation of blastomycotic meningitis and should suggest the diagnosis. This report broadens the clinical spectrum of blastomycotic meningitis and suggests that cytologic examination of CSF is a useful way to establish this diagnosis.

Use of cerebrospinal fluid lactic acid concentration in the diagnosis of fungal meningitis.

A patient with a several year history of normal pressure hydrocephalus was found to have an infection owing to Cryptococcus neoformans. Cryptococcal infection was not suspected until typical cells were observed in a Wright's stained smear of cerebrospinal fluid (CSF). A review of past medical findings in this patient showed elevated CSF values for lactic acid and protein. This case prompted us to review the use of lactic acid as an indicator of fungal meningitis and compare it to other more commonly used nonspecific indicators of fungal meningitis, notably the concentrations of glucose and protein, and the number of leukocytes in CSF. In our institution, all 10 culturally proven cases of fungal meningitis, for which the lactic acid concentration in the CSF was available, were found to have an elevated lactic acid concentration (range 3.2 to 13.3 mmol per L vs normal range 0.8 to 2.8 mmol per L). No other nonspecific indicator was elevated in all 10 patients. In view of the poor sensitivity of stained smear or wet preparations and cultures, when less than five ml of CSF are used for culture, an elevated lactic acid value in a patient with or without signs of meningitis should raise the suspicion of fungal infection.

The spectrum of primary blastomycotic meningitis: a review of central nervous system blastomycosis.

Three cases of meningitis with initial and exclusive neurological involvement prompted a review of the clinical, cerebrospinal fluid, and pathological findings in an additional 78 patients with central nervous system blastomycosis. The first patient of the 3 had progressive cerebellar dysfunction as the result of chronic basilar meningitis. The second had a C8-T1 radiculopathy without other evidence of superior sulcus syndrome, and subsequent acute fatal meningitis. The third had aseptic, benign, self-limited meningitis followed by clinically obvious systemic blastomycosis. Diagnosis is difficult, and it is likely that other cases have been presumptively treated for tuberculous meningitis. A more aggressive approach to diagnosis is proposed that takes into account the condition of the patient, the likelihood of dissemination at necropsy, and the frequent meningeal infections that are negative on culture of lumbar CSF.