Assessing Possible Additive Effects of tDCS and Mirror Therapy Treatments for Phantom Pain

Does Transcranial Direct Current Stimulation (tDCS) Improve the Effect of Mirror Therapy? A Double-blind Randomized Controlled Study in Patients With Phantom Limb Pain.

In this study we will examine assess if treatment with transcranial Direct Current Stimulation (tDCS) improve the analgesic effects of mirror therapy for patients with phantom pain of lower extremity. The study will include 3 arms: only mirror therapy, mirror therapy + sham tDCS, and mirror therapy + active tDCS.

Phantom pain following amputation is difficult to treat, resulting in many patients who suffer. One of the mechanisms suspected to contribute to phantom pain is abnormal plasticity and reorganization of the cortex.

Mirror therapy is a behavioral technique that proven useful for the treatment of phantom pain, yet the analgesic effects are unfortunately moderate and not long lasting. The assumed underlying mechanism of mirror therapy treatment is the induction of neuronal plasticity in the opposite direction than the abnormal reorganization of the cortex (due to the amputation), and by that relive pain.

tDCS is a non-invasive technique that allow the administration of low currents directly to the scalp. The currents affect the cortex, and result in changes to the membrane potential of neurons in the stimulated area. This in turn affects the tendency of those neurons to generate action potentials.

It was hypothesize that combination of mirror therapy and tDCS treatment could result in additive effects. According to this hypothesis, the effects of the mirror therapy could be enhanced by the tDCS treatment. The aim of the current study is to investigate this hypothesis.

Inclusion Criteria:

1. Age 18 or older
2. Underwent unilateral lower limb amputation in the past 3 months. A
3. Reported average phantom pain of 4 or more in the past week.
4. No change in other medications 1 week prior to enrollment, not including SOS.
5. Able understand the purpose of the study and to provide informed consent.

Exclusion Criteria:

1. Ferromagnetic metal in the head or neck.

1. Epilepsy or prior seizures within the last 1 year.
2. Suffering from severe depression
3. History of unexplained fainting or loss of consciousness