A 59-year-old woman presented with three days of fever, vomiting and hypophonia. ENT evaluation revealed left vocal cord paralysis. Neurological exam was significant for trigeminal nerve (TN) paresthesia and ataxic gait. MRI demonstrated ring-enhancing medullary lesions with central diffusion restriction and TN enhancement. CSF testing revealed RBC 2000 cells/µL, WBC 13 cells/µL with neutrophilic predominance (53%), protein 69 mg/dL. Broad CNS antimicrobial coverage was initiated but discontinued given negative cultures and PCR. Autoimmune and neoplastic evaluations were also negative.
Subsequent MRI’s demonstrated lesion expansion into the cervical cord and interval enhancement in the cerebellum and supratentorial leptomeninges. Clinical exam worsened to reflexive posturing of extremities and inability to breathe requiring mechanical ventilation. The cerebellar lesion was biopsied and sent for additional testing including negative CDC amoeba testing and positive Mayo broad-range bacterial PCR and sequencing (BRBPS). Karius serum testing also returned positive. The patient was restarted on appropriate antibiotics with clinical and radiographic improvement after several weeks.
This case emphasizes the importance of recognizing rhombencephalitis as a more common presentation of CNS listeriosis in immunocompetent patients, the limitations of standard PCR panels, and the usefulness of DNA sequencing. Earlier use of DNA sequencing may be particularly important in invasive listeriosis given high mortality rates.