Sonkodi Balázs, Hortobágyi Tibor
Department of Health Sciences and Sport Medicine, University of Physical Education, Budapest, Hungary.
ELKH-DE Cerebrovascular and Neurodegenerative Research Group, Department of Neurology, University of Debrecen, Debrecen, Hungary.
Open Med (Wars). 2022 Mar 1;17(1):397-402. doi: 10.1515/med-2022-0444. eCollection 2022.
Amyotrophic lateral sclerosis (ALS) is a fatal, multisystem neurodegenerative disease that causes the death of motoneurons (MNs) progressively and eventually leads to paralysis. In contrast, delayed onset muscle soreness (DOMS) is defined as delayed onset soreness, muscle stiffness, loss of force-generating capacity, reduced joint range of motion, and decreased proprioceptive function. Sensory deficits and impaired proprioception are common symptoms of both ALS and DOMS, as impairment at the proprioceptive sensory terminals in the muscle spindle is theorized to occur in both. The important clinical distinction is that extraocular muscles (EOM) are relatively spared in ALS, in contrast to limb skeletal muscles; however, the blink reflex goes through a gradual impairment in a later stage of disease progression. Noteworthy is, that, the stretch of EOM induces the blink reflex. The current authors suggest that the impairment of proprioceptive sensory nerve terminals in the EOM muscle spindles are partially responsible for lower blink reflex, beyond central origin, and implies the critical role of Piezo2 ion channels and Wnt-PIP2 signaling in this pathomechanism. The proposed microinjury of Piezo2 on muscle spindle proprioceptive terminals could provide an explanation for the painless dying-back noncontact injury mechanism theory of ALS.
肌萎缩侧索硬化症（ALS）是一种致命的多系统神经退行性疾病，它会逐渐导致运动神经元（MNs）死亡，最终导致瘫痪。相比之下，延迟性肌肉酸痛（DOMS）被定义为延迟发作的酸痛、肌肉僵硬、力量产生能力丧失、关节活动范围减小以及本体感觉功能下降。感觉缺陷和本体感觉受损是ALS和DOMS的常见症状，因为理论上两者都会发生肌梭中本体感觉感觉末梢的损伤。重要的临床区别在于，与肢体骨骼肌不同，ALS患者的眼外肌（EOM）相对不受影响；然而，在疾病进展的后期，眨眼反射会逐渐受损。值得注意的是，EOM的伸展可诱发眨眼反射。本文作者认为，EOM肌梭中本体感觉感觉神经末梢的损伤部分导致了眨眼反射降低，这超出了中枢起源的范畴，并暗示了Piezo2离子通道和Wnt-PIP2信号在这一病理机制中的关键作用。所提出的Piezo2对肌梭本体感觉末梢的微损伤可以为ALS的无痛逆行性非接触损伤机制理论提供一种解释。
