False impressions from clear cerebrospinal fluid and a normal computed tomography scan: the pressure is still on for a diagnosis.

We report the case of a 33-year-old man presenting with seizures following a 3 week, non-specific febrile illness characterized by progressive confusion. Despite the presence of risk factors, his HIV serology was negative and he had no premorbid suggestion of immunocompromise. We describe the difficulties in making the diagnosis of cryptococcal meningitis in the presence of cerebrospinal fluid analysis with the only abnormality initially being hypoglycorrhachia. This case also highlights the importance of measuring an opening pressure, a procedure which should be routine, but is often neglected in the performance of lumbar punctures. Finally, this case reinforces the maxim that cranial CT cannot be relied upon alone to diagnose intracranial hypertension, which also requires clinical examination, including fundoscopy.