Fact-sheet: Toxoplasmosis of brain
Updated on 03/31/2020 at 9:36 AM
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Definition
Cerebral infection by the protozoan Toxoplasma gondii
Location:
Predominant involvement of the corticosubcortical junction, thalamus, and basal ganglia
Diagnosis to consider in immunocompromised patients with any neurological sign
Clinical features
Fever, headaches, neurological deficits, seizures, altered consciousness, decreased visual acuity
Any neurological disturbance in an immunocompromised patient should raise suspicion of this diagnosis
Radiography
Residual calcifications sometimes visible in children
CT
Hypodense lesion with peripheral rim enhancement after contrast injection
Lack of sensitivity
MRI
Multiple, rounded, diffuse lesions.
Significant perilesional edema.
T1: hyposignal with nodular or ring enhancement.
T1 after gadolinium injection: eccentric target enhancement.
T2: appearance of a necrotic mass with concentric target.
Diffusion: low central necrotic signal and elevated ADC.
Perfusion: very low rCBV
Spectroscopy: decreased NAA and lipid peak.
Management
Empirical treatment
Brain biopsy if single lesion and failure of empirical treatment
Differential diagnosis
Lymphoma of brain
Low-grade glial tumor