What to Know About Cryptococcal Meningitis

Medically Reviewed by Christopher Melinosky, MD on March 07, 2024
Written by Parang Mehta
4 min read

Cryptococcus is a yeast, which is a kind of fungus. This yeast infects those with poor immunity, like people with HIV.

Cryptococcus has a liking for the nervous system, and it often causes meningitis — specifically called cryptococcal meningitis.

Knowing the symptoms of cryptococcal meningitis can help you in early diagnosis and successful treatment.

Your brain is protected by three layers of membranes called the meninges. Meningitis is the inflammation of these meninges, and it can happen because of a  bacterial, viral, or fungal infection.

Cryptococcal meningitis increases the pressure inside your skull and can destroy one or several parts of your brain. Cryptococcal meningitis pathophysiology (disease process) can also harm your ears and eyes.

In humans, cryptococcal meningitis is caused by either Cryptococcus neoformans or Cryptococcus gattii — with the former species being more common. 

‌Cryptococci are opportunistic pathogens — which means that they cause disease only when your immune system is weak. About 85% of patients who have cryptococcal meningitis are people with HIV infection. 

Other conditions, patients who also have poor immunity, include:

  • Diseases of the blood
  • ‌Organ failure syndromes — like liver failure
  • ‌Organ transplant receivers who’re on immunosuppressive drugs
  • ‌Immunodeficiency syndromes
  • ‌Treatment with steroids and other drugs that reduce immunity

If you're living with any of these conditions, you should be on the lookout for cryptococcal meningitis symptoms.

‌Cryptococci form spores. These spores are widespread — especially in soil, bird droppings, and decaying wood.

So, you can get infected with cryptococci by inhaling these spores. But, this infection doesn't spread from person to person — like, for example, flu does. 

‌In people with a good immune system, the inhaled spores enter the lungs, where they are destroyed by alveolar macrophages — the guardian white blood cells in the lungs. The pathophysiology of cryptococcal meningitis depends on a weakened immune system. 

The yeast takes advantage of poor immunity to reach the lymph nodes — where it multiplies into many cells. From there, these cells spread and most often affect the nervous system. They grow in the meninges, gradually causing symptoms.

Cryptococcal meningitis symptoms appear slowly and they commonly include:

  • Headache
  • ‌Fever
  • ‌Excessive sleepiness and lethargy
  • Stiff neck
  • ‌Nausea and vomiting
  • ‌Eye problems — photophobia (inability to tolerate light), diplopia (seeing double), and loss of vision
  • ‌Hearing loss
  • ‌Seizures

‌Many of these symptoms show up based on how poor your body's immune response is. For example, if you have HIV or reduced immunity from any other cause, you may show few symptoms in the early stages of the disease, delaying the diagnosis. This delay allows the yeast to slowly grow into a large mass and worsen your condition.

‌If you think you've got some of the above symptoms, visit your doctor right away. Your doctor will evaluate you for meningitis and consider cryptococcal meningitis if you're at risk for it. 

For a confirmed diagnosis, your doctor will ask you to get your cerebrospinal fluid (CSF) tested — a liquid that bathes your central nervous system to provide it with all the necessary nutrients and moisture.

In this test, a thin needle will be inserted into your spine from the low back to obtain your CSF. The CSF will then be analyzed chemically. It’ll also be cultured to check if it contains any disease-causing organisms like cryptococcus. 

Your doctor may also ask for a CT scan or MRI scan of the brain. Other tests will include capsular antigen detection and lateral flow assay. 

Cryptococcal meningitis pathophysiology includes brain damage. So, if the disease is left untreated for a long time, it can cause some serious damage to your nervous system — some of which can’t be reversed.

This damage can include seizures, reduced consciousness, coma, and even death.

Even with the best available treatment, mortality rates are 15% to 30%.

‌Antifungal drugs work against cryptococci, but the treatment needs several months to completely cure you.

The Infectious Disease Society of America’s evidence-based guideline for treating cryptococcal disease hasn’t been updated since 2010 because no new drugs have been developed for this infection.

‌The above guideline recommends that the focus should be on effectively treating the underlying condition (e.g., HIV), and the use of antifungal drugs like:

  • Amphotericin B
  • ‌Fluconazole
  • ‌Flucytosine
  • ‌Itraconazole

T‌reatment of this cryptococcal meningitis can go on for months. You may have to stay in hospital for part of it. 

‌The success of the treatment depends on how early the diagnosis was made and what the underlying condition is. For example, 15% to 25% of people who have cryptococcal meningitis as well as HIV die, even when modern anti-HIV treatment is effective. 

Other underlying conditions are more difficult to control, and these people have higher mortality rates. 

If you’re among the people at risk of getting cryptococcal meningitis, always be on the lookout for the early signs and symptoms and keep checking with your doctor.