Chronic meningoencephalomyelitis caused by Nocardia nova infection: a case report and literature review.

A 25-year-old female zookeeper presented with 3-month history of sore throat and headache, 2-month intermittent fever, and 1-month dizziness. Neurological examination revealed bilateral nystagmus, left-sided sensory loss, ataxia, and subtle meningeal signs. Brain and cervical spinal cord MRI showed multiple enhancing lesions with central vein signs. Cerebrospinal fluid (CSF) analysis demonstrated elevated pressure (240 mmH2O) and leukocytosis (140 × 106/L). Serum MOG-IgG was positive (1:32), while CSF metagenomic next-generation sequencing (mNGS) confirmed Nocardia nova infection. Initial treatment with trimethoprim-sulfamethoxazole (TMP-SMX), amikacin, and imipenem-cilastatin was followed by regimen adjustment to TMP-SMX plus minocycline at 6 weeks. One-month post-therapy, repeat CSF showed normalized pressure, reduced leukocytes, negative mNGS, and MRI evidence of lesion regression. Complete symptom resolution occurred 2 months after treatment initiation. This case exemplifies a rare presentation of N. nova-induced meningoencephalomyelitis with craniospinal involvement in an immunocompetent individual.