As of 2014 the cause was not clear and was a subject of ongoing research. However a small sample of people with<unk>  connected to their left leg have had MRI scans that showed less gray matter in the right side of their superior parietal lobule. The amount of gray matter missing was correlated to the strength of the patients' desire to remove their leg.
Body integrity dysphoria
Gender dysphoria
Emotional lability
Morbid love
Sexual anhedonia
Emotional detachment
Automatism 
Body image disturbance