Neurological Manifestations of

Background: Methods: The national MYCADO cohort included 1309 adults hospitalized with MP infection during the 2023-2024 French epidemic. An ancillary study identified and described MP-related central (CNS) and peripheral (PNS) nervous system manifestations. Data were retrospectively extracted from medical records, with clinical follow-up up to 3 months after discharge. Results: Twenty-eight patients with neurological manifestations attributable to MP were identified (2.1% of the cohort). Of these, 19 affected the CNS, including encephalitis (n = 8), myelitis (n = 3), encephalo-myelitis (n = 2), isolated meningitis (n = 6), and cerebral vasculitis (n = 1). Nine involved the PNS: Guillain-Barré syndrome (n = 6), peripheral polyneuropathy (n = 2), and multifocal neuropathy (n = 1). The median age (interquartile range) was 35 years (29-49) years; 60.7% were men. Neurological symptoms appeared a median of 7 days after MP infection onset. Nearly half (46.4%, n = 13) required intensive care; neurological failure was the leading cause of intensive care unit transfer (12/13, 92.3%). Compared with MP patients without neurological manifestations, those with neurological involvement had longer hospital stays (13 vs 9 days; Conclusions: In adults, MP infection causes rare but diverse and frequently severe neurological manifestations that worsen clinical course and result in long-term disability.