To describe a rare case of nocardiosis in immunocompetent patient.

Cerebral nocardiosis is a rare opportunistic infection, accounting for only 2% of all cerebral abscesses, and typically occurs in immunocompromised individuals.

We report a 38-year-old female with past medical history of pituitary adenoma who presented with altered mental status. Patient reported sudden onset right sided vision loss, followed by an episode of generalized tonic clonic seizure with loss on consciousness.

Neurological examination was remarkable for right homonymous hemianopsia. Emergent CT head showed a 6.6 cm zone of hypoattenuation centered within the left occipital lobe, involving the posterior temporal and part of the parietal lobe with vasogenic edema. Patient was started on levetiracetam for seizure prophylaxis and steroids for cerebral edema. MRI of the brain showed a 1.2 cm left occipital lesion with moderate surrounding vasogenic edema, consistent with a pyogenic abscess. Patient was started on empiric vancomycin and cefepime. CT chest showed patchy nodular airspace and ground glass opacity within left upper lobe. Patient underwent emergent left craniotomy with brain mass resection and abscess drainage. Intra-operative tissue culture grew nocardia. Brain biopsy showed filamentous organisms consistent with nocardia. Patient was treated with 4 weeks of intravenous imipenem, Trimethoprim/Sulfamethoxazole (TMP/SMX) and oral linezolid followed by oral TMP/SMX and Amoxicillin/Clavulanic acid to complete a course of 6 months. She was continued on TMP/SMX alone thereafter. Genetic, immunodeficiency and autoimmune work up were negative, except for slightly abnormal Anti-SSA levels. Follow up CT head and MRI brain did not show any new concerning findings.

Although seen mainly in immunocompromised hosts, nocardia can present with brain abscess in immunocompetent hosts. This case highlights the unique challenges regarding the need for early diagnostic and therapeutic interventions in such cases including surgical resection, choosing appropriate antibiotic regimen as well as duration.