Neuromelioidosis presenting with the 'tunnel sign': A case report.

A 31 yr old male came with complaints of fever of 2 weeks duration with headache. Later he developed right hemiparesis with dysarthria followed by left hemiparesis with anarthria. On examination there was spastic quadriparesis. Magnetic resonance imaging (MRI) brain contrast showed multiple ring-enhancing lesions of 2-4 cm size in bilateral cerebral hemispheres with central diffusion restriction. On coronal contrast sequence there was a thick-walled tubular curvilinear enhancing lesion traversing through the corpus callosum. Two sets of blood cultures were obtained before initiation of empirical antituberculous therapy, which was started along with dexamethasone. The patient's sensorium gradually deteriorated over 4 days and elective intubation was done. Repeat CT brain scan showed worsening of oedema with midline shift. Neurosurgery consultation was taken, and the patient was taken for decompressive craniectomy. Despite decompressive craniectomy, the patient succumbed to the illness on the 6th day of hospital admission. Blood cultures subsequently grew Burkholderia pseudomallei, supporting the diagnosis of neuromelioidosis. Although the diagnosis was supported by characteristic neuroimaging findings and positive blood cultures, direct microbiological confirmation from the intracranial lesion was unavailable.