Dorsal root ganglia hypertrophy as in vivo correlate of oxaliplatin-induced polyneuropathy

PurposeTo investigate in vivo morphological and functional correlates of oxaliplatin-induced peripheral neuropathy (OXA-PNP) by magnetic resonance neurography (MRN).MethodsTwenty patients (7 female, 13 male, 58.9±10.0 years) with mild to moderate OXA-PNP and 20 matched controls (8 female, 12 male, 55.7±15.6 years) were prospectively enrolled. All patients underwent a detailed neurophysiological examination prior to neuroimaging. A standardized imaging protocol at 3.0 Tesla included the lumbosacral plexus and both sciatic nerves and their branches using T2-weighted fat-saturated sequences and diffusion tensor imaging. Quantitative assessment included volumetry of the dorsal root ganglia (DRG), sciatic nerve normalized T2 (nT2) signal and caliber, and fractional anisotropy (FA), mean diffusivity (MD), axial (AD) and radial diffusivity (RD). Additional qualitative evaluation of sciatic, peroneal, and tibial nerves evaluated the presence, degree, and distribution of nerve lesions.ResultsDRG hypertrophy in OXA-PNP patients (207.3±47.7mm3 vs. 153.0±47.1mm3 in controls, p = 0.001) was found as significant morphological correlate of the sensory neuronopathy. In contrast, peripheral nerves only exhibited minor morphological alterations qualitatively. Quantitatively, sciatic nerve caliber (27.3±6.7mm2 vs. 27.4±7.4mm2, p = 0.80) and nT2 signal were not significantly changed in patients (1.32±0.22 vs. 1.22±0.26, p = 0.16). AD, RD, and MD showed a non-significant decrease in patients, while FA was unchanged.ConclusionOXA-PNP manifests with morphological and functional correlates that can be detected in vivo by MRN. We report hypertrophy of the DRG that stands in contrast to experimental and postmortem studies. DRG volume should be further investigated as a biomarker in other sensory peripheral neuropathies and ganglionopathies.

旨在通过磁共振神经影像学（MRN）研究奥沙利铂诱导的外周神经病变（OXA-PNP）的活体形态学及功能相关性。方法：纳入20名轻至中度OXA-PNP患者（其中女性7名，男性13名，平均年龄58.9±10.0岁）及20名匹配对照者（女性8名，男性12名，平均年龄55.7±15.6岁）进行前瞻性研究。所有患者在神经影像学检查前均接受了详细的神经生理学检查。在3.0特斯拉磁场下，采用标准化成像方案，对腰骶丛及坐骨神经及其分支进行T2加权脂肪饱和序列和弥散张量成像。定量评估包括背根神经节（DRG）的体积测量、坐骨神经标准化T2（nT2）信号强度和直径，以及各向异性分数（FA）、平均扩散率（MD）、轴向扩散率（AD）和径向扩散率（RD）。对坐骨、腓神经和胫神经的定性评估，以评估神经损伤的存在、程度及分布。结果：OXA-PNP患者的DRG肥大（207.3±47.7mm3 vs. 对照组153.0±47.1mm3，p = 0.001）被确定为感觉神经元病的显著形态学相关性。相反，外周神经在形态学上仅表现出轻微的改变。定量上，患者的坐骨神经直径（27.3±6.7mm2 vs. 27.4±7.4mm2，p = 0.80）和nT2信号强度没有显著变化（1.32±0.22 vs. 1.22±0.26，p = 0.16）。AD、RD和MD在患者中显示出非显著性降低，而FA保持不变。结论：OXA-PNP在活体MRN检查中表现出可检测到的形态学及功能相关性。我们报告了与实验性和尸检研究形成对比的DRG肥大。DRG体积应进一步作为其他感觉外周神经病变和神经节病的生物标志物进行研究。