• Medical management with either sulfadiazine 4 to 6 g per day or clindamycin 600 mg four times per day and pyrimethamine 50 to 100 mg per day and folinic acid 25 mg per day (to prevent dose-related bone marrow suppression caused by the pyrimethamine)
  
• Corticosteroids are sometimes used in addition to first line treatment to reduce symptoms caused by edema.
  
• Cerebral toxoplasmosis is the most common cerebral mass lesion in patients with AIDS and in most instances develops when the CD4+ T-lymphocyte count falls below 100 cells/mcL. Thus, HIV status and T-lymphocyte count should be sent prior to surgical intervention.

Operative Planning

• Review images–magnetic resonance imaging (MRI) or computed tomography scan will show multiple ring enhancing lesions. The absence of increased uptake in mass lesions on single photon emission computed tomography and decreased activity on positron emission tomography are characteristic of toxoplasmosis encephalitis.

Special Equipment

• MRI wand navigation for stereotactic needle biopsy or aspiration, or for guidance in craniotomy for surgical resection

Positioning

• Varies depending on location of lesion and type of surgery planned

Stereotactic Biopsy/Aspiration

Open Craniotomy

• Advantages: can remove lesion or multiple lesions completely
  
• Disadvantages: more invasive than stereotactic needle biopsy/aspiration

• If toxoplasmosis is confirmed, continue medical therapy for at least 6 weeks.
  
• Follow clinically for regrowth, especially in immunocompromised patients.