Neurotoxoplasmosis - concentric target sign


MRI findings are suspicious of an inflammatory cause.

The presence of concentric rings in the T2w images is highly suspicious for neurotoxoplasmosis.

Differential diagnoses based on imaging alone were:
1. Cerebral Toxoplasmosis in an immunocompromised patient
2. CNS lymphoma in an immunocompromised patient
3. Balo concentric sclerosis (usually showing only mild perifocal edema) in an immunocompetent patient

Blood tests revealed positive results for HIV (yet unknown to the patient).
Immunochemical findings were typical for Neurotoxoplasmosis.
Toxoplasma gondii IgG > 13 000 IU/ml
Toxoplasma gondii IgA AK 1:1024 (normal < 1:16)
HIV-1 RNA quantitatively copies/ml: >280 000
CD 4+ T-Cells 7/μl (normal 500-2000/μl)

The Patient was thus diagnosed with AIDS (Neurotoxoplasmosis being one of the AIDS-defining illnesses in an HIV infected patient) and was treated with 1. Antiretroviral therapy, 2. Antitoxoplasmosis therapy (Pyrimethamine, Clindamycin, Folate), 3. Antiepileptic medication.