Author: Gupta Rakesh K, Kumar Sunil

Infective central nervous system (CNS) diseases, though preventable, yet remain a major cause of morbidity and mortality in the tropics. Polymerase chain reaction (PCR) based techniques and neuroimaging have revolutionized the specific diagnosis of many CNS infections but due to involvement of many bacterial, viral, parasitic and fungal pathogens with almost similar but polymorphic presentations the diagnostic dilemma continues, especially in subacute and chronic infections. Information on microbes causing disease in particular region is important so that triaging of many tests based on likely pathogens can be adopted. Magnetic resonance imaging (MRI) is more sensitive than computed tomography (CT) in the detection of focal or diffuse parenchymal lesions and vasculitic complications. Furthermore, better detection and characterization of infectious brain lesions are possible today using the advanced MRI techniques, such as diffusion weighted imaging (DWI), perfusion weighted imaging and proton MR spectroscopy