Mirrored, imagined and executed movements differentially activate sensorimotor cortex in amputees with and without phantom limb pain

Abstract

Extended viewing of movements of the intact hand in a mirror as well as motor imagery has been shown to decrease pain in phantom pain patients. We used functional magnetic resonance imaging to assess the neural correlates of mirrored, imagined and executed hand movements in 14 upper extremity amputees - 7 with phantom limb pain (PLP) and 7 without phantom limb pain (non-PLP) and 9 healthy controls (HC). Executed movement activated the contralateral sensorimotor area in all three groups but ipsilateral cortex was only activated in the non-PLP and HC group. Mirrored movements activated the sensorimotor cortex contralateral to the hand seen in the mirror in the non-PLP and the HC but not in the PLP. Imagined movement activated the supplementary motor area in all groups and the contralateral primary sensorimotor cortex in the non-PLP and HC but not in the PLP. Mirror- and movement-related activation in the bilateral sensorimotor cortex in the mirror movement condition and activation in the sensorimotor cortex ipsilateral to the moved hand in the executed movement condition were significantly negatively correlated with the magnitude of phantom limb pain in the amputee group. Further research must identify the causal mechanisms related to mirror treatment, imagined movements or movements of the other hand and associated changes in pain perception.

Linking Pain and the Body: Neural Correlates of Visually Induced Analgesia

“…For example, phantom limb pain after amputation may be a by-product of reorganization of cortical maps of the body (Flor et al, 2006). Interestingly, some reports suggest that simply viewing the body (or the mirror image of an intact limb appearing where the amputated limb is now missing) can reduce phantom limb pain (Ramachandran et al, 1995), and may do so through signals that control plastic processes of cortical reorganization (Lotze et al, 2001;Diers et al, 2010). That is, integrating the painful body part within a stable representation of the body may be an important mechanism for pain regulation.…”

The Effect of Mirror Therapy on the Management of Phantom Limb Pain

“…[13,14,[26][27][28][29][30] It is a method that can be used independently by nurses to manage the care of a patient with PLP. In addition, it provides a great opportunity for amputees to be able to manage their pain themselves.…”

“…[4,[6][7][8][9] Individual physiological, environmental, and psychological factors are involved in the etiology of PLP. [4,[10][11][12][13][14][15] Pathophysiology of PLP is not clearly known yet. However, it is speculated that central and peripheral nerve systems play an important role in the occurrence of PLP.…”

“…According to cortical reorganization theory, there are neuroplastic changes in the cortical map after the amputation of the limb, and these changes might be related to PLP. [1,3,14,18] Clinical characteristics of PLP differ from patient to patient; however, the most commonly reported characteristics are burning, stabbing, tingling, a sensation of being pinned down, cramps, itching, pressure, burning, electric shock-like feeling, heat or cold, and throbbing. [3,4,11,12,17,19,20] The feeling of a phantom limb can be so vivid that the patient may attempt to stand up and walk, [12] or sometimes it may feel like a paralyzed limb.…”

“…[24,25] The results of his first study with mirror therapy encouraged many scientists to conduct new studies on this therapy method. [13,14,[26][27][28][29][30] Since mirror therapy is a method that can be taught and practiced easily and independently, it should have a place in the nursing care plan of patients with PLP. However, there is currently no study in the literature related to the role of nurses in using mirror therapy for management of PLP.…”