Introduction/Objective:

Cryptococcal meningoencephalitis is an opportunistic infection that typically presents with headache, encephalopathy, fever, and symptoms of increased intracranial pressure (ICP). Serial lumbar punctures are indicated in cases of elevated ICP and sometimes require the placement of a lumbar drain. We report a rare case of cryptococcal meningoencephalitis with normal opening pressure in a patient with chronic lymphocytic leukemia (CLL) receiving the investigational Bruton’s tyrosine kinase (BTK) inhibitor, Nemtabrutinib. 

Conclusion:
This case emphasizes the need for increased awareness and prompt investigation of opportunistic infections in CLL patients, particularly those treated with novel BTK inhibitors like Nemtabrutinib. Furthermore, the atypical presentation with normal ICP in cryptococcal meningoencephalitis highlights the potential for an unusual disease course. Clinicians should maintain a high index of suspicion for fungal infections, such as cryptococcal meningoencephalitis, in CLL patients with normal intracranial pressure receiving immunosuppressive therapy.