Tuberculous meningitis in the southwest United States

Abstract

This community-based study analyzed 54 patients with definite or probable tuberculous meningitis (TBM) in New Mexico from 1970 through 1990. Patients ranged in age from 4 months to 86 years. The highest age-specific incidence occurred in the elderly, but 22% of patients were less than 10 years old. Native American patients were overrepresented. Patients were as likely to live in small towns as in large urban cities. Symptoms were present for a median of 13 days before admission. The majority of patients had fevers, headache, stiff neck, and mental changes, such as confusion or lethargy. No patient was admitted comatose. Focal neurologic signs were present in 33%. Laboratory testing found hyponatremia in 79%, pulmonary infiltrates on chest x-ray in 40%, ventricular dilatation on CT or MRI in 52%, and tuberculomas in 16%. PPD skin tests were positive in 64%. CSF cultures grew Mycobacterium tuberculosis in 50%, but colony counts were always lower than 10²/ml. As a consequence, acid-fast stains of CSF sediment were reported as positive in only 4%. Six patients were not diagnosed during the hospitalization and died of complications. Twenty-three percent of patients who were appropriately treated also died of complications during the initial hospitalization. Tuberculous meningitis continues to be an important disease in small communities, and affects all ages and ethnic and socioeconomic backgrounds.