A 25-year-old woman presented in altered sensorium that developed after an episode of complex partial seizure 6 days ago. She had a history of low-grade fever, anorexia and weight loss for 6 months. She also had productive cough for 4 weeks. She was febrile and breathing fast. Her neck was supple and no meningeal signs were present. Deep tendon reflexes were hyperactive and fundus examination was normal. She had generalised lymphadenopathy.

Serum electrolytes were normal. Lumbar puncture was performed and cerebrospinal fluid (CSF) opening pressure was normal. CSF examination showed increased proteins, normal glucose …