To describe a case and raise awareness on the utmost importance of early imaging in Nocardia farcinica infections as an important neurological complication in immunocompromised patients.

Nocardia farcinica is a rare cause of brain abscesses and can present as a diagnostic challenge. It has disseminated hematogenous spread, most commonly involving the CNS, particularly the brain, but it can also involve the eye, bone, joint, heart, kidney, lung and skin, among others. Brain nocardiosis symptoms vary from asymptomatic to headache, lethargy, confusion, seizures, and sudden onset of neurologic problems. Conventional methods for diagnosis of Nocardia species include blood culture, microscopy, and tissue sample, but the performance is not satisfied. We report a case of brain abscess due to N. farcinica diagnosed by peripheral abscess cultures in conjunction with imaging.

An 81-year-old man with rheumatoid arthritis and vasculitis chronically on immunotherapy including prednisone, hydroxychloroquine, and methotrexate presented to the emergency department with right leg pain. He was found to have a right thigh abscess that status post drainage grew cultures positive for N. farcinica. His neurologic exam was non focal and unremarkable. Despite the lack of neurological symptoms given that Nocardia has a strong predilection to the CNS, brain imaging was obtained. Magnestic resonance imaging (MRI) of the brain with and without contrast demonstrated a 1 cm left frontal ring enhancing lesion with central restricted diffusion and mild vasogenic edema without significant mass effect. Blood cultures came back negative. He was treated with Trimethroprim-Sulfamethoxazole and Imipenem for 8 weeks. A subsequent brain MRI 2 months later revealed significant radiological improvement, with only a vague 5mm enhancement in the left frontal area. Patient remained neurologically asymptomatic.

Nocardia species are highly neurotropic and should necessitate brain imaging even in the absence of neurologic symptoms.