Clinical Characteristics Associated with the PLP-PLS Index, a New Potential Metric to Phenotype Phantom Limb Pain
Jorge Ortega-Márquez,
Justyna Garnier,
Lucas Mena,
Ana Victoria Palagi Vigano,
Eleonora Boschetti Grützmacher,
Gabriel Vallejos-Penaloza,
Valton Costa,
Daniela Martinez-Magallanes,
Antonio Vaz de Macedo,
Waynice Neiva de Paula-Garcia,
Denise Saretta Schwartz,
Felipe Fregni,
Kevin Pacheco-Barrios
Affiliations
Jorge Ortega-Márquez
Master of Medical Sciences in Clinical Investigation, Harvard Medical School, Boston, MA 02115, USA
Justyna Garnier
Department of Psychology, SWPS University of Social Sciences and Humanities, 03-815 Warsaw, Poland
Lucas Mena
Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05508-220, Brazil
Ana Victoria Palagi Vigano
Grupo de Ombro e Cotovelo, Faculdade de Medicina do ABC, Santo André 09060-870, Brazil
Eleonora Boschetti Grützmacher
Praxis Am Lichterfelde West, 12205 Berlin, Germany
Gabriel Vallejos-Penaloza
Departamento de Ginecología y Obstetricia, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago 7610315, Chile
Valton Costa
Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
Daniela Martinez-Magallanes
Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
Antonio Vaz de Macedo
Hematology Clinic, Hospital da Polícia Militar, Belo Horizonte, Minas Gerais 30110-013, Brazil
Waynice Neiva de Paula-Garcia
AC Camargo Cancer Center, São Paulo 01509-010, Brazil
Denise Saretta Schwartz
Departamento de Clínica Médica, Faculdade de Medicina Veterinária e Zootecnia (FMVZ), Universidade de São Paulo, São Paulo 05508-220, Brazil
Felipe Fregni
Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
Kevin Pacheco-Barrios
Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
Background: Phantom limb pain (PLP) is highly prevalent after amputation. However, the influence of non-painful sensations (PLS) remains unclear. This study examines the PLP-PLS index as a novel tool to differentiate PLP from PLS and explores the association of clinical factors with the index. Methods: We conducted a cross-sectional analysis of baseline data from 112 participants in a previous factorial trial in patients with unilateral traumatic lower limb amputation. Linear regression models were used to examine the associations between the index and various demographic, psychological and clinical factors. Logistic and Poisson regression, and e-value calculation were utilized for sensitivity analyses. Results: Adjusted multivariable linear regression models demonstrated significant associations of phantom movement sensation (β: −1.532; 95% CI: −2.615 to −0.449; p = 0.006) and time since amputation (β: 0.005; 95% CI: 0.0006 to 0.0101; p = 0.026) with the PLP-PLS index. These findings were confirmed by multivariable logistic regression (phantom movement sensation OR: 0.469; 95% CI: 0.200 to 1.099, p = 0.082; time since amputation OR: 1.003; 95% CI: 1.00003 to 1.007; p = 0.048) and sensitivity analyses. Conclusions: Time since amputation and phantom movement sensation likely reflect distinct phenotypes and potential mechanisms for PLP and PLS. The PLP-PLS index is a promising clinical tool for selecting therapies to prevent/treat PLP and for measuring treatment effects to modulate phantom pain. These findings emphasize the importance of understanding the mechanisms underlying PLP and PLS for improving clinical management and guiding future research.
