Head CT without contrast
Shows multiple subcortical lesions with predilection for basal ganglia
Contrast usually not needed; if obtained, will show ring enhancing lesions
CSF
Helpful but high rate of false negatives
Serology not generally helpful since antibodies common in general population
Shows multiple subcortical lesions with predilection for basal ganglia
Contrast usually not needed; if obtained, will show ring enhancing lesions
Helpful but high rate of false negatives
Toxoplasmosis
Lymphoma
Histoplasmosis
More commonly single lesion in the periventricular white matter or corpus callosum
Ehrlichiosis
Cerebral TB
Cryptococcosis
Characteristic inflammatory appearance with isodense exudate filling basal cisterns