Let's start with cryptococcus. This causes a meningitis, cryptococcal meningitis. Those words
should ring through your mind. Cryptococcus neoformans is the leading cause of an infectious
meningitis in patients with AIDS. In fact, this occurs in 20% of AIDS patients in Africa. This is a
fungal infection. Cryptococcus is a fungus, it's found in the soil that's contaminated with
pigeon feces. Infection is acquired through inhalation or hematogenous spread to the
meninges and the brain. How do patients present? Well here we see the typical clinical
manifestations. Headache and fever are the hallmark of a meningitis and are seen in these
patients. Typically when we're evaluating for a meningitis, we think of headache, fever, and
neck stiffness, meningismus, nuchal rigidity. But meningeal signs with cryptococcal meningitis
are often mild. This is not an acute meningitis, this is a slowly developing chronic meningitis
where meningeal irritation is less prominent. Typically in these patients, we see other late
complications from their meningitis. Signs of altered mental status, bilateral 6th nerve palsies.
Again, remember that a bilateral abducens nerve palsy is sign of elevated intracranial
pressure until proven otherwise. And papilloedema, which is really important to evaluate in
these patients. The diagnosis primarily involves testing the CSF and we can look for the
cryptococcal antigen which is typically what's done these days for patients. Historically, we
would do an India ink stain, which you can see here on the image in the right side of the slide.
The India ink labels the capsule that is around this fungus and you can see it here, the
organism on the inside and the capsule is highlighted around the outside. This is commonly
tested and something that you should be familiar with. And this is a fungal infection so we
treat it with antifungals, amphotericin B often followed by fluconazole. Cryptococcal meningitis.