What Causes Cracking Sound In The Neck And Dizziness?

My mom said she went to massage the back of her head and neck and she bent her neck to a side and she said she heard a crack in the neck and right after the dizziness started with hot flashes and she could feel her heartbeat in her ears. We went to the emergency room on sunday night monday morning only to tell us that they don't know what she had... the family doctor said it was an ear infection and gave her antibiotics. She felt better with the antibiotics for the ear infection but after the crack.... nothing helped. Please help! Btw... the crack was today, Wednesday!