FCA1-0149

A 45-year-old woman gives a two-week history of fatigue, muscle cramps, and paraesthesia of her fingers and toes. She has low serum calcium and low serum parathyroid hormone levels on investigations. She appears slightly confused, likely due to hypocalcaemia, and cannot give a full account of her past medical history, but can recall that she recently was admitted to the hospital. What is the most likely cause of her hypoparathyroidism?