Title : A case of cryptococcal meningitis & anti-nmdar encephalitis in a patient with myelofibrosis in rural victoria
Abstract:
Background: The incidence rate of myelofibrosis is 6 in 100,000 people in Australia. There are only a few reports of cryptococcal meningitis associated with ruxolitinib use in patients with myelofibrosis. The exact prevalence of fungal infections in patients with myelofibrosis is unknown. Furthermore, anti-NMDAr encephalitis has a prevalence of one in 1.5 million people per year. The concomitant findings of cryptococcal meningitis and anti-NMDAr encephalitis have rarely been documented with the first case of an individual presenting with both documented in 2020. The pathophysiology of both, to date, is poorly understood. This case presentation hopes to highlight the subtleties in presentation in a highly functional individual who was eventually diagnosed with both cryptococcal meningitis and anti-NMDAr encephalitis, as well as ways to mitigate the risk of misdiagnosis. Signed consent was provided by both the patient and next of kin.
Clinical and social presentation: A 66-year-old man presents to ED with a one-week history of subjective fevers, sweats and lethargy on a background of myelofibrosis. He usually works at home or from the office and is independent with his activities of daily living (ADLs).
Relevant history: During his admission, he had no documented fevers, however, complained of a worsening headache, which was managed with paracetamol. His sweats and lethargy continued. His inflammatory markers trended downwards and his hyponatremia also resolved spontaneously during the admission. He was discharged after a 3-day admission. 5 days later, he re-presented to the ED with continued fevers and sweats since the previous admission, however, also with headache and worsening confusion.
Investigation: Bloods on re-presentation:
FBE: Hb 97, WCC 18, Plt 109
UEC: Na 133, K 3.8, Scr 99, eGFR 68
CRP: 13
Imaging on re-presentation:
CTB: NAD
MRB: Nil evidence of meningoencephalitis or cause for patient's symptoms on MRB
Other investigations:
CSF analysis: +ve for cryptococcal antigen (Cryptococcus neoformans) and +ve for anti-NMDAR antibody
Diagnosis: Cryptococcal meningitis & anti-NMDAR encephalitis
Management: Initially managed locally at a regional hospital with flucytosine and amphotericin B. Transferred back to local hospital for rehabilitation. However, patient’s confusion continued to worsen, leading to multiple Code Greys as an inpatient and a few episodes of abscondence. The patient’s kidney function continued deteriorating on the regime of flucytosine and amphotericin B despite continued infectious diseases input virtually. Patient was transferred to a tertiary centre for multidisciplinary input between infectious diseases, neurology and psychiatry.
Discussion and learnings: MRI brain did not reveal any significant changes in 3 of 29 instances of cryptococcal meningitis. While this does not warrant a routine consideration of lumbar puncture, in the case of immunocompromised patients, there should be perhaps a lower threshold to consider performing a lumbar puncture. This may, however, present a challenge in more remote areas without access to experienced clinicians. Whilst worsening confusion is not specific to anti-NMDAr encephalitis, despite the rarity of the condition, clinicians should consider ordering a broader encephalitic screen on CSF analysis, particularly in immunocompromised patients.
