Toxoplasmosis

Background

• Most common cause of focal encephalitis in patients with AIDS

Clinical Features

1. Headache
2. Fever
3. Focal neurologic deficits
4. AMS
5. Seizures

Diagnosis

• Head CT w/o contrast
  • Shows multiple subcortical lesions w/ predilection for basal ganglia
  • Contrast usually not needed; if obtained, will show ring enhancing lesions
• CSF
  • Helpful but high rate of false negatives

DDX

• Lymphoma
  • More commonly single lesion in the periventricular white matter or corpus callosum
• Cerebral TB
  • Characteristic inflammatory appearance w/ isodense exudate filling basal cisterns
• Fungal infection

Treatment

• Abx
  • Pyrimethamine 200mg loading dose PO followed by 50-75mg PO QD x6-8wk AND
  • Sulfadiazine 1-1.5gm PO q6hr x 6–8wk AND
  • Folinic acid 10mg PO QD x6–8wk
• Corticosteroids
  • Consider dexamethasone 4mg IV q6hr for significant edema or mass effect

Disposition

• Admit

Source

• Tintinalli