Ways to alleviate phantom pain?

Phantom pain is described as a pain that gives you a false impression of coming from one or particular part of the body but it does actually there. It makes you feel it’s coming from a part every time but you can’t find. Earlier these sensational pains are regarded as post – amputation process or phenomenon but after making a good research now the doctors say that these pains generally originates from the spinal cord and so the sensations are drastic
 Some of the best ways to treat this phantom pain are medications, non invasive therapies and invasive therapies
The medications given for the treatment of phantom pain are
     Antidepressants – they are amitriptyline and nortriptyline these often can relieve the pain caused by damaged nerves.
     Anticonvulsants – epilepsy drugs – like gabapentin, carbamazepine are usually used to treat pain.
     Narcotics – opioid drugs such as codeine are used.
The non – invasive methods which are used to treat the phantom pain are
        Nerve stimulation
        Electric artificial bulb
        Mirror box
        Acupuncture

The invasive methods which are used to treat the phantom pain are
        Injections
        Spinal cord stimulations.

 The causes of phantom pain?