Isonicotinic acid hydrazide (isoniazid) is one of the most effective agents in tuberculosis therapy (1). This agent rapidly permeates the bacterial cell membrane via passive diffusion (2). The central nervous system tuberculosis is being observed in patients who are intravenous drug abusers, with AIDS and AIDS-related complex (3). MRI and contrast- enhanced CT has been the methods of choice for non-invasive diagnosis of this elusive ...