Background & Aims

Lower limb amputation has an estimated worldwide prevalence of 35.3 million people. Many aspects influence the quality of life of amputees, but key features to consider are Phantom Limb Pain (PLP) and Phantom Limb Sensations (PLS). While PLP and PLS integrate the clinical spectrum of amputee patients, both are also reported to have differences in the central, peripheral and psychological adaptation processes, therefore the consideration of these both aspects are essential when it comes to study patients with amputation. However, up to today, there are not enough clinical tools integrating PLP-PLS in the clinical-therapeutic decision-making of amputee patients with PLP. This study intends to test the PLP-PLS index as a clinical and therapeutic sub-phenotype tool in Phantom Limb Pain patients.

Methods

We conducted a cross-sectional baseline study of 112 patients from one of the largest mechanistic clinical trials investigating amputees with lower limb amputation and PLP. As a primary analysis, it was performed a univariate linear regression analysis followed by an iterative forward selection process to generate a multivariate linear regression model. A secondary analysis was conducted using a logistic regression model with the PLP-PLS index as a categorical variable, and e-value calculation for the most significant variables observed in regression models was performed as a sensitivity analysis.

Results

For the primary analysis, time since amputation (?: 0.0056; CI: 0.00068 – 0.1058; P=0.026); negative predictors – movement (?:-1.338; CI: -2.384 to -0.2920; P=0.013) and anxiety (?: – 0.0548; CI: -0.0548 to -0.0002; P=0.049) were found as positive predictors. The secondary analysis showed the side of amputation (OR: 2.19; CI: 1.010615- 4.748628), PLS- cold (OR: 2.11; CI: 0.8683393-5.154894) time since amputation (OR: 1.003; CI: 0.9995063-1.007142), anxiety (OR: 0.9612169; CI:0.924029-0.9999014), and PLS-movement (OR: 0.5294118; CI: 0.2441955-1.147756) as significant variables. E-value was estimated for movement (coef.-1.53, SE 0.55).

Conclusions

In this study, we demonstrated an association of the PLP-PLS Index with phantom limb sensation related to movement and anxiety, which might represent the potential of the PLP_PLS Index as an explanatory tool of compensatory sensorimotor adaptation in patients with lower limb amputations. However, the PLP-PLS index should be tested in further studies in pre-post intervention to make further assumptions of the index as a clinical sub-phenotype tool in patients with phantom limb pain.

References

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Presenting Author

Kevin Pacheco-Barrios

Poster Authors

Kevin Pacheco-Barrios

MD, MPH, MSc

Spaulding Rehabilitation Hospital, Harvard Medical School.

Lead Author

Jorge Ortega Márquez

Spaulding Rehabilitation Hospital, Harvard Medical School.

Lead Author

Justyna Garnier

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Lucas Mena

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Ana Victoria Palagi Vigano

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Eleonora Boschetti Grützmacher

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Gabriel Vallejos-Penaloza

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Daniela Martinez Magallanes

Spaulding Rehabilitation Hospital, Harvard Medical School.

Lead Author

Valton Costa

Spaulding Rehabilitation Hospital, Harvard Medical School.

Lead Author

Antonio Vaz de Macedo

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Waynice Neiva de Paula-Garcia

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Denise Saretta Schwartz

Principal and practice of clinical research program, Harvard TH Chan School of Public Health.

Lead Author

Felipe Fregni

Spaulding Rehabilitation Hospital, Harvard Medical School.

Lead Author

Topics

  • Mechanisms: Psychosocial and Biopsychosocial