Brain abscess due to Nocardia is a rare central nervous system infection that primarily affects immunocompromised patients. The Nocardia asteroides complex accounts for most infections. This study reports a brain abscess caused by Nocardia araoensis , a rare species. A healthy 56-year-old man with no known comorbidities presented to the emergency department with a 15-day history of progressive holocranial headache associated with paresthesia of the left upper limb and gait disturbance. Neurological examination revealed language prosody abnormalities with occasional word substitution, with no additional deficits. Magnetic resonance imaging showed an expansive lesion with features suggestive of a brain abscess, including irregular peripheral enhancement, internal septations, and diffusion restriction. Biopsy confirmed Nocardia araoensis . The patient has been undergoing prolonged antibiotic therapy with progressive clinical improvement. Although Nocardia infections are more prevalent in immunocompromised individuals, cases in immunocompetent patients have been reported. They may involve multiple organs, most commonly the lungs. CNS involvement is rare and may present as brain abscess, often misdiagnosed as neoplasms or other infectious etiologies. Identification of N. araoensis is challenging due to slow growth and possible culture negativity when inappropriate techniques are used. Rare infections such as N. araoensis should be considered in the differential diagnosis of CNS expansive lesions even in immunocompetent patients. Appropriate therapy ‒ including antibiotics with good CNS penetration and, in some cases, surgical intervention ‒ is essential for effective treatment and prevention of complications.
Isabel et al. (Sun,) studied this question.