A 65-year-old woman has diabetes and mild hypertension. She is noted to have some diabetic retinopathy, and she states that she cannot feel her legs. She has recurrent episodes of lightheadedness when she gets up in the morning. She has come to the hospital because she fainted this morning.

What can be the most likely cause of her syncope? * This patient case is from the Docplexus Editorial Team for educative purposes only. Source: 100 Cases In Internal Medicine