Protective and Risk Factors for Phantom Limb Pain and Residual Limb Pain Severity

• DOI: 10.1111/papr.12881
• Publication Date: 2020-03-16T14:30:19Z
• Authors: Marionna Münger; Camila B. Pinto; Kevin Pacheco‐Bar...; Dante Duarte; Muhamed Enes Gunduz; Marcel Simis; Linamara R. Batti...; Felipe Fregni
• Keywords: Adult; Male; Middle Aged; Amputation, Surgical; Young Adult; 03 medical and health sciences; Cross-Sectional Studies; 0302 clinical medicine; Amputees; Lower Extremity; Phantom Limb; Risk Factors; Humans; Neuralgia; Female; Aged

AbstractIntroductionThe exact mechanisms underlying the development and maintenance of phantom limb pain (PLP) are still unclear. This study aimed to identify the factors affecting pain intensity in patients with chronic, lower limb, traumatic PLP.MethodsThis is a cross‐sectional analysis of patients with PLP. We assessed amputation‐related and pain‐related clinical and demographic variables. We used univariate and multivariate models to evaluate the associated factors modulating PLP and residual limb pain (RLP) intensity.ResultsWe included 71 unilateral traumatic lower limb amputees. Results showed that (1) amputation‐related perceptions were experienced by a large majority of the patients with chronic PLP (sensations: 90.1%, n = 64; residual pain: 81.7%, n = 58); (2) PLP intensity has 2 significant protective factors (phantom limb movement and having effective treatment for PLP previously) and 2 significant risk factors (phantom limb sensation intensity and age); and (3) on the other hand, for RLP, risk factors are different: presence of pain before amputation and level of amputation (in addition to the same protective factors).ConclusionThese results suggest different neurobiological mechanisms to explain PLP and RLP intensity. While PLP risk factors seem to be related to maladaptive plasticity, since phantom sensation and older age are associated with more pain, RLP risk factors seem to have components leading to neuropathic pain, such as the amount of neural lesion and previous history of chronic pain. Interestingly, the phantom movement appears to be protective for both phenomena.