A case report of diffuse intra-abscess hemorrhage in Listeria monocytogenes rhombencephalitis and its implications for early diagnosis and therapeutic monitoring

We report a 74-year-old female presenting with fever, right eyelid ptosis, and peripheral facial palsy following dental treatment, who was initially misdiagnosed as acute brainstem infarction based on MRI showing T2-hyperintense signal in the right pons with restricted diffusion. Despite dual antiplatelet therapy and empiric antibiotics, brainstem dysfunction worsened. Serial MRI revealed lesion expansion, multifocal “worm-like” abscesses formation, nodular satellite lesions, and diffuse intra-abscess hemorrhage. Cerebrospinal fluid metagenomic next-generation sequencing (mNGS) identified Listeria monocytogenes . This case highlights the sequential MRI evaluations’ pivotal role in detecting early signs of Listeria CNS infection and disease progression, thereby facilitating timely adjustments to the therapeutic strategy.