A 63-year-old man presented with gait difficulty, slowing of all motor activity, and memory loss. He had been diagnosed and treated for Parkinson disease over the previous year but without any improvement. A computed tomography scan showed extensive calcifications throughout the brain (Fig. 1). The serum calcium concentration was 3.1 mg/dL (0.78 mmol/L) [reference interval, 8.4–10.2 mg/dL (2.0–2.6 mmol/L)]. 

Computed tomography scan of the patient's brain.


  1. What conditions might cause such severe brain calcification?
  2. What other laboratory tests should be considered for this patient?
  3. What is the likely diagnosis?

Read the article here for the answers.