47 yr old woman/ diagnosed w/ bobbing head phenomenon.Not baby doll syndrome. cant find bobble head phenomen

My 47 yr old cousin ( who has been suffering with bulging disks in her back..just recently started to bob her head.. As, if to say 'yes"..She went to the ER and, they said she had Bobble Head Phenomenon. I have not been able to find that anywhere. There is babydoll bobble head syndrome but, I find nothing re:bobble head phenomenon. can someone help me.