Complex sentence: Bryant's long, tragic decline was caused by Adiposis dolorosa, or Dercum's disease with which she was diagnosed in 1928, it was marked by extreme weight gain, fatigue, and mental confusion.
Split into simpler sentences: Bryant's long, tragic decline was caused by Adiposis dolorosa, or Dercum's disease, with which she was diagnosed in 1928. It was marked by extreme weight gain, fatigue, and mental confusion.