What Causes Pain In Arm And Under Armpits?

hello
i have very bad pain in my left arm
running all the way down to my fingers
i have breast implants under the muscle
the pain is also in my armpit and side of the left breast
i have been for an mri scan and seen a neurologist who has done electric shock tests down my left arm
they still don t know what it is
the pain is worse after physical exercise
i have bulimia also
what do u think it is?
please help