CT & MRI IMAGING IN CNS TUBERCULOSIS:

AUTHORS: Dr Himadri Sikhor Das, Dr P.Hatimota, Dr P.Hazarika, Dr C.D.Choudhury.
INSTITUITION: MATRIX, Guwahati -5, Assam, India.
ADD FOR CORRESPONDENCE: MATRIX, Guwahati -5, Assam, India.
drhsdas@gmail.com

ABSTRACT: Tuberculosis (TB) of the central nervous system (CNS) is a granulomatous infection caused by Mycobacterium tuberculosis. Infection is by haematogenous spread from a primary focus, usually the lung. Infection starts in subpial or subependymal cortical focus (ie, Rich focus), resulting in a granuloma that erodes into the subarachnoid space causing basal leptomeningitis. The meningitis usually causes communicating hydrocephalus, but it may also cause obstruction of the foramina of Luschka and Magendie, resulting in obstructive hydrocephalus. Vasculitis involving the lenticulostriate and thalamoperforatoring arteries may occur and cause small infarcts in the deep gray nuclei and deep white matter. Other manifestations of tuberculosis are focal parenchymal granulomas (eg, tuberculomas), tuberculous abscesses, tuberculous cerebritis, and pachymeningitis. In addition, spinal cord infection is less common, but it results in either arachnoiditis, spondylodiskitis (Pott’s spine) or uncommonly, focal intramedullary tuberculomas. Clinical diagnosis can be difficult; therefore, imaging has an important role in establishing the diagnosis. The imaging spectrum of CNS tuberculosis along with few atypical cases are presented in our paper.