Article

Limb amputation may lead to chronic painful sensations referred to the absent
limb, ie phantom limb pain (PLP), which is likely subtended by maladaptive
plasticity. The present study investigated whether transcranial direct current
stimulation (tDCS), a noninvasive technique of brain stimulation that can
modulate neuroplasticity, can reduce PLP. In 2 double-blind, sham-controlled
experiments in subjects with unilateral lower or upper limb amputation, we
measured the effects of a single session of tDCS (2 mA, 15 min) of the primary
motor cortex (M1) and of the posterior parietal cortex (PPC) on PLP, stump pain,
nonpainful phantom limb sensations and telescoping. Anodal tDCS of M1 induced a
selective short-lasting decrease of PLP, whereas cathodal tDCS of PPC induced a
selective short-lasting decrease of nonpainful phantom sensations; stump pain and
telescoping were not affected by parietal or by motor tDCS. These findings
demonstrate that painful and nonpainful phantom limb sensations are dissociable
phenomena. PLP is associated primarily with cortical excitability shifts in the
sensorimotor network; increasing excitability in this system by anodal tDCS has
an antalgic effect on PLP. Conversely, nonpainful phantom sensations are
associated to a hyperexcitation of PPC that can be normalized by cathodal tDCS.
This evidence highlights the relationship between the level of excitability of
different cortical areas, which underpins maladaptive plasticity following limb
amputation and the phenomenology of phantom limb, and it opens up new
opportunities for the use of tDCS in the treatment of PLP.
CI - Copyright (c) 2013 International Association for the Study of Pain. Published by
Elsevier B.V. All rights reserved.

Langue : ANGLAIS