AUTHOR=Feil Katharina , Ruf Benjamin , Behling Felix , Kozak Gabor , Gohla Georg , Riessen Reimer , Haap Michael , Poli Sven , Hennersdorf Florian , Ziemann Ulf , Mengel Annerose TITLE=Case Report: severe Mycoplasma pneumoniae-associated acute disseminated encephalomyelitis in an adult: challenges in diagnosis and management JOURNAL=Frontiers in Medicine VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1627241 DOI=10.3389/fmed.2025.1627241 ISSN=2296-858X ABSTRACT=We report a rare case of severe Mycoplasma (M.) pneumoniae-associated acute disseminated encephalomyelitis (ADEM) in a previously healthy 26-year-old woman. The patient presented with delayed-onset encephalopathy following a mild respiratory infection. Rapid neurological deterioration, signs of transtentorial herniation, and refractory intracranial hypertension necessitated emergency decompressive hemicraniectomy. Diagnostic workup revealed elevated M. pneumoniae IgM and borderline PCR positivity. The patient was successfully treated with corticosteroids, intravenous immunoglobulin, and targeted azithromycin. Complete clinical and radiological recovery was achieved. This case emphasizes the need for awareness of severe M. pneumoniae-associated CNS manifestations and highlights the challenges in diagnosis and management.