Phantom limb pain after amputation in diabetic patients does not differ from that after amputation in nondiabetic patients

Abstract

There is a commonly held belief that diabetic amputees experience less phantom limb pain than nondiabetic amputees because of the effects of diabetic peripheral neuropathy; however, evidence to verify this claim is scarce. In this study, a customised postal questionnaire was used to examine the effects of diabetes on the prevalence, characteristics, and intensity of phantom limb pain (PLP) and phantom sensations (PS) in a representative group of lower-limb amputees. Participants were divided into those who had self-reported diabetes (DM group) and those who did not (ND group). Participants with diabetes were further divided into those with long-duration diabetes (>10years) and those with short-duration diabetes. Two hundred questionnaires were sent, from which 102 responses were received. The overall prevalence of PLP was 85.6% and there was no significant difference between the DM group (82.0%) and the ND group (89.4%) (P=0.391). There was also no difference in the prevalence of PS: DM group (66.0%), ND group (70.2%) (P=0.665). The characteristics of the pain were very similar in both groups, with sharp/stabbing pain being most common. Using a 0-10 visual analogue scale, the average intensity of PLP was 3.89 (±0.40) for the DM group and 4.38 (±0.41) for the ND group, which was not a statistically significant difference (P=0.402). Length of time since diagnosis of diabetes showed no correlation with average PLP intensity. Our findings suggest that there is no large difference in the prevalence, characteristics, or intensity of PLP when comparing diabetic and nondiabetic amputees, though a larger adjusted comparison would be valuable.