Listeria monocytogenes associated with acute axonal polyneuropathy

Introduction: Listeria monocytogenes is a rare cause of neurological complications and is not known to affect the peripheral nervous system (PNS). We present a case of acute motor axonal neuropathy (AMAN) associated with Listeria monocytogenes infection.Case Presentation: A 60-year-old man developed progressive, symmetric, ascending weakness over one week, along with severe constipation. He had no history of trauma, infection, or vaccination but lived in precarious conditions. Neurological examination revealed multiple cranial nerve palsies, flaccid tetraparesis, absent reflexes, and albumin-cytologic dissociation in cerebrospinal fluid (CSF). Initial diagnosis was Guillain-Barré syndrome (GBS), and intravenous immunoglobulin (IVIg) was initiated. However, the patient showed no improvement and developed respiratory failure, requiring mechanical ventilation. Extensive workup, including PCR analysis of CSF, identified Listeria monocytogenes. Nerve conduction studies confirmed AMAN. The patient was treated with a 21-day course of intravenous ampicillin, leading to neurological stabilization and eventual full recovery after six months.Conclusion: This case highlights Listeria monocytogenes as a potential infectious cause of acute polyneuropathy, particularly in individuals with poor living conditions. It also raises the possibility of direct axonal damage by the bacterium. Early recognition and targeted antibiotic therapy may improve outcomes in similar cases.