Neuromodulation Center and Center for Clinical Research Learning, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, United States.
Universidad San Ignacio de Loyola, Vicerrectorado de Investigación, Unidad de Investigación para la Generación y Síntesis de Evidencias en Salud, Lima 01425, Peru.
Pain Med. 2023 May 2;24(5):528-537. doi: 10.1093/pm/pnac205.
The management of phantom limb pain (PLP) is still challenging due to a partial understanding of its neurophysiological mechanisms. Structural neuroimaging features are potential biomarkers. However, only a few studies assessed their correlations with clinical severity and treatment response. This study aims to explore the association between brain gray matter volume (GMV) with phantom limb manifestations severity and PLP improvement after neuromodulatory treatments (transcranial direct current stimulation and mirror therapy). Voxel-based morphometry analyses and functional decoding using a reverse inference term-based meta-analytic approach were used. We included 24 lower limb traumatic amputees with moderate to severe PLP. We found that alterations of cortical GMV were correlated with PLP severity but not with other clinical manifestations. Less PLP severity was associated with larger brain clusters GMV in the non-affected prefrontal, insula (non-affected mid-anterior region), and bilateral thalamus. However, only the insula cluster survived adjustments. Moreover, the reverse inference meta-analytic approach revealed that the found insula cluster is highly functionally connected to the contralateral insula and premotor cortices, and the decoded psychological processes related to this cluster were "rating," "sustained attention," "impulsivity, " and "suffering." Moreover, we found that responders to neuromodulatory treatment have higher GMV in somatosensory areas (total volume of S1 and S2) in the affected hemisphere at baseline, compared to non-responders, even after adjustments.
由于对其神经生理机制的部分理解，幻肢痛 (PLP) 的管理仍然具有挑战性。结构神经影像学特征是潜在的生物标志物。然而，只有少数研究评估了它们与临床严重程度和治疗反应的相关性。本研究旨在探索脑灰质体积 (GMV) 与幻肢表现严重程度以及神经调节治疗（经颅直流电刺激和镜像治疗）后 PLP 改善之间的关联。使用基于反向推理术语的元分析方法进行基于体素的形态测量分析和功能解码。我们纳入了 24 名下肢创伤性截肢者，他们有中度至重度 PLP。我们发现皮质 GMV 的改变与 PLP 严重程度相关，但与其他临床表现无关。PLP 严重程度越低，与未受影响的前额叶、岛叶（未受影响的中前区域）和双侧丘脑的大脑簇 GMV 越大相关。然而，只有岛叶簇幸存下来。此外，反向推理元分析方法表明，发现的岛叶簇与对侧岛叶和运动前皮质高度功能连接，并且与该簇相关的解码心理过程是“评分”、“持续注意力”、“冲动”和“痛苦”。此外，我们发现与神经调节治疗有反应的患者在基线时受累半球的体感区域（S1 和 S2 的总体积）的 GMV 较高，与无反应者相比，即使在调整后也是如此。
