Retrospective Study to Assess the Evolution of MRI or CT Lesions in Treated CNS Nocardiosis

Overview

Nocardiosis is a rare infection caused by bacteria of the genus Nocardia spp. It primarily affects immunocompromised individuals, such as solid organ or hematopoietic stem cell transplant recipients, as well as individuals with anti-GM-CSF antibodies. The infection typically begins by inhalation, affecting the lungs, with frequent hematogenous spread to the brain and soft tissues. Cerebral involvement is present in 20 to 40% of cases, although 40% of patients remain neurologically asymptomatic. Treatment consists of prolonged antibiotic therapy and, sometimes, surgical drainage for large or refractory abscesses. Mortality associated with cerebral involvement varies between 20 and 40%. Although radiological improvements are observed under treatment, the link between image changes and clinical prognosis remains uncertain. Regular radiological monitoring is recommended during and after treatment, although the expected evolution has not been described in the literature.

Nocardiosis is a rare infection caused by bacteria of the genus Nocardia spp. It primarily affects immunocompromised individuals, such as solid organ or hematopoietic stem cell transplant recipients, as well as individuals with anti-GM-CSF antibodies. The infection typically begins by inhalation, affecting the lungs, with frequent hematogenous spread to the brain and soft tissues. Cerebral involvement is present in 20 to 40% of cases, although 40% of patients remain neurologically asymptomatic. Brain imaging is essential for diagnosis, with MRI often being preferred due to its sensitivity. Images often show multiple abscesses, but without sufficient specificity to differentiate nocardiosis from other pathogens. New MRI techniques could improve lesion characterization. Treatment consists of prolonged antibiotic therapy and, sometimes, surgical drainage for large or refractory abscesses. Mortality associated with cerebral involvement varies between 20 and 40%. Although radiological improvements are observed under treatment, the link between image changes and clinical prognosis remains uncertain. Regular radiological monitoring is recommended during and after treatment, although the expected evolution has not been described in the literature.

Conditions