Manuela Lefort-Holguin_2025_Neuro-sensitization

Feline osteoarthritis (OA) is characterized by somatosensory neuro-sensitization, which can be assessed through quantitative sensory testing. It was hypothesized that somatosensory neuro-sensitization would increase with OA severity, as categorized through the validated Montreal Instrument for Cat Arthritis Testing, for Veterinarians (MI-CAT(V)).
Healthy (n=10) and cats with naturally occurring OA (n=121) were enrolled in this prospective, negatively controlled study. Peripheral and spinal sensitization were respectively assessed by paw withdrawal threshold (PWT) and response to mechanical temporal summation (RMTS). PWT determined allodynia threshold. Derived from MI-CAT(V), cats were sorted into four validated OA severity clusters, from absent to severe OA. Outcomes were compared across allodynia status (healthy, non-allodynic and allodynic) and OA clusters, while testing for the influence of demographic data, with alpha set at 5%.
The PWT, RMTS, MI-CAT(V) outcomes and age accurately discerned between healthy and OA animals (P<0.002), but not body weight. Non-allodynic cats had similarly altered MI-CAT(V) and RMTS to allodynic cats, but they were younger (P=0.010) and had a higher PWT than allodynic (P<0.001), and similar PWT (P=0.925) but older (P<0.001) than healthy cats. Spinal sensitization was similar in the three OA-affected clusters (mild-moderate-severe; P=1.000), but MI-CAT(V) categorized them sensitively (P<0.001). The mild cluster included more non-allodynic cats than the moderate (P=0.021) and severe (P=0.026) clusters. Interestingly, 32% of mild OA cats were allodynic, when the proportion increased to 61% in pooled moderate/severe OA cats (P=0.013).
OA cats are sensitized compared to healthy cats, and peripheral sensitization seems to increase with OA severity, which influences pain phenotype.

猫骨关节炎（Feline osteoarthritis, OA）以躯体感觉神经致敏（somatosensory neuro-sensitization）为特征，可通过定量感觉测试（quantitative sensory testing）进行评估。本研究假设：经验证的猫关节炎兽医评估蒙特利尔工具（Montreal Instrument for Cat Arthritis Testing for Veterinarians, MI-CAT(V)）分级的OA严重程度越高，躯体感觉神经致敏程度也随之升高。
本前瞻性阴性对照研究共纳入10只健康猫与121只自然罹患OA的猫。分别通过爪回缩阈值（paw withdrawal threshold, PWT）与机械性时间总和反应（response to mechanical temporal summation, RMTS）评估外周致敏（peripheral sensitization）与脊髓致敏（spinal sensitization）情况，其中PWT用于测定痛觉异常阈值（allodynia threshold）。基于MI-CAT(V)的分级结果，将猫分为4个经过验证的OA严重程度集群，从无OA到重度OA。本研究比较了不同痛觉异常状态（健康、非痛觉异常、痛觉异常）与OA集群间的各项检测指标，并检验了人口统计学数据的影响，显著性水平设为5%。
PWT、RMTS、MI-CAT(V)结果与年龄可有效区分健康猫与OA患猫（P<0.002），但体重无法实现该鉴别。非痛觉异常患猫的MI-CAT(V)与RMTS结果与痛觉异常患猫相似，但它们年龄更小（P=0.010），且PWT更高（相较于痛觉异常患猫，P<0.001）；同时其PWT与健康猫无显著差异（P=0.925），但年龄更大（P<0.001）。三个OA受累集群（轻度、中度、重度）的脊髓致敏程度相似（P=1.000），但MI-CAT(V)可灵敏地对其进行分级（P<0.001）。轻度OA集群中非痛觉异常患猫的占比高于中度（P=0.021）与重度（P=0.026）集群。值得注意的是，轻度OA患猫中32%存在痛觉异常，而合并的中度/重度OA患猫中该比例升至61%（P=0.013）。
相较于健康猫，OA患猫存在致敏现象，且外周致敏程度似乎随OA严重程度升高而增加，这会影响疼痛表型（pain phenotype）。