A previously well 35-year-old male presented with a one month history of generalized progressive headaches, mental status changes, and behavioral changes in the form of aggression and somnolence. His initial physical examination was unremarkable apart from bilateral papilledema and delirium. Investigations, including complete blood count (CBC), urea, creatinine, electrolytes, erythrocyte sedimentation rate (ESR), liver function tests (LFT), thyroid stimulating hormone (TSH), EKG, and chest x-ray, were within normal limits. An immediate computed tomogram (CT) scan of the head showed acute hydrocephalus. A shunt was inserted, and a CSF sample was obtained. It showed an elevated cell count (WBC 26x109 cells/L, 82% lymphocytes) and elevated protein (7.05 g/L). The CSF staining for AFB was negative, as were the bacterial and viral cultures. Cytological and fungal staining was also negative. Weighted with gadolinium, T1 and FLAIR MRI sequences displayed an extensive white matter abnormality with prominent meningeal and hypothalamic enhancement (Figure 1). Tuberculosis (TB) was the main diagnostic consideration. Sarcoidosis, lymphoma and lepto-meningeal metastasis were also considered. The CSF cytology was negative on two occasions, making a neoplastic cause less likely. Tuberculosis was felt to be the most likely etiological diagnosis, as there were no systemic findings of sarcoidosis on his initial presentation.