You have had pain in your leg from a herniated disc for two years that increased in intensity three months ago. You were treated by a clinic that used a machine with suction cups and vibration. I am unclear about the identity of this machine but it may be an electrical muscle stimulator or an interferential current generator machine.
While being treated by this machine, you developed paresthesias into both your hands on the pinky side associated with “constant weakness”. Your doctor told you the cause was a herniated disc in your neck.
First, your hand symptoms could be generated by the neck, the shoulder, the elbow or the wrist. The disorders are called a cervical herniated disc, thoracic outlet syndrome, cubital tunnel syndrome or tunnel of Guyon syndrome. Having bilateral symptoms might make a disc herniation less likely. Bilateral thoracic outlet syndrome is common. Bilateral cubital tunnel or Guyon tunnel syndrome is less common.
I think that the machine placed on your lower back most likely did not cause the hand symptoms. You at this point need a good physical examination to determine what is causing your symptoms- not an MRI. If the examination points to your neck as the source, then an MRI might be warranted.