Nocardia abscess during treatment of brain toxoplasmosis in a patient with aids, utility of proton MR spectroscopy and diffusion-weighted imaging in diagnosis

• Published in: Clinical neurology and neurosurgery 2006-07, Vol.108 (5), p.493-498
• Main Authors: Soto-Hernández, José Luis, Moreno-Andrade, Talía, Góngora-Rivera, Fernando, Ramírez-Crescencio, María Antonieta
• Format: Article
• Language: English
• Subjects: Acquired Immunodeficiency Syndrome - complications; Acquired Immunodeficiency Syndrome - drug therapy; Adult; Anti-Bacterial Agents - therapeutic use; Anti-Retroviral Agents - therapeutic use; Anticonvulsants - therapeutic use; Antiprotozoal Agents - therapeutic use; Biological and medical sciences; Brain abscess; Brain Abscess - complications; Brain Abscess - microbiology; Brain Abscess - pathology; Brain toxoplasmosis; Clindamycin - therapeutic use; Diffusion Magnetic Resonance Imaging; Drug Therapy, Combination; HIV infection; Human immunodeficiency virus; Humans; Magnetic Resonance Spectroscopy; Male; Medical sciences; Neurology; Neurosurgery; Nocardia asteroides; Nocardia asteroides - isolation & purification; Nocardia Infections - complications; Nocardia Infections - microbiology; Nocardia Infections - pathology; Phenytoin - therapeutic use; Proton magnetic resonance spectroscopy; Protons; Pyrimethamine - therapeutic use; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Toxoplasmosis, Cerebral - complications; Toxoplasmosis, Cerebral - drug therapy
• ISSN: 0303-8467; 1872-6968
• DOI: 10.1016/j.clineuro.2005.01.010

We report the case of a 30-year-old man with known HIV-positive status who developed, 4 months prior to admission, recurrent left partial motor seizures followed by left hemiparesis. At another hospital, contrasted CT scan of the head revealed right frontal hypodense lesion with mass effect and focal contrast enhancement. A small left occipital lesion was also present. HIV-associated brain toxoplasmosis was considered and phenytoin, pyrimethamine, clindamycin and antiretrovirals were administered. Hemiparesis improved but, 3 weeks prior to admission, he developed progressive headache and bilateral visual defects. Upon admission to our center, he was found with left homonymous hemianopsia, right hemiparesis and a large hypodense left occipital lesion on a head CT scan. Proton MR spectroscopy showed lactate at 1.3 ppm, amino acids at 0.9 ppm, and diffusion-weighted imaging (DWI) revealed hyperintensity at the lesion, suggesting a pyogenic abscess. Aspiration yielded purulent material and Nocardia asteroides grew in culture. The patient was treated with trimethoprim–sulfametoxazole and recovered with a mild visual field residual defect.