Schestatsky Pedro, Valls-Solé Josep, Felix-Torres Vitor, Guarany Fábio Coelho, Castellote Juan M, Pérez Daniel, Costa João
Department of Neurology, Hospital de Clínicas de Porto Alegre, Brazil; Department of Neurology, Hospital Clínic, Universitat de Barcelona, Spain.
Neurosci Lett. 2009 Oct 2;463(2):140-4. doi: 10.1016/j.neulet.2009.07.062. Epub 2009 Jul 24.
Voluntary muscle contraction is accompanied by an increase in sympathetic nerve activity. The sympathetic skin response (SSR) is a simple and non-invasive method of autonomic assessment that reflects a synchronized activity of the sweat glands. The aim of our study was to examine the possible relationship between isometric muscle contraction (IC) and changes in the SSR.
In 11 healthy right-handed volunteers, we recorded the SSR from the palm of the hand induced by contralateral triceps IC (mSSR) of variable intensities and durations. We measured the latency, duration, amplitude, waveform and habituation index (HI) of the mSSR, in comparison to the SSR induced by supramaximal electrical stimulation (eSSR) of the brachial plexus at the axillae.
A single mSSR was always present at a mean latency of 1.34+/-0.5s after the onset of IC. Response amplitude, but not latency or duration, correlated positively with the intensity of IC (r=0.67; p<0.001). The latency was shorter, the duration was longer and the HI was reduced in the mSSR in comparison to the eSSRs (ANOVA; p<0.05 for all comparisons).
The mSSR is likely generated endogenously together with the motor commands since inputs from muscle afferents cannot account for response onset. This, together with its low level of habituation, underscores the possibilities of physiological and clinical studies using the mSSR, especially in the assessment of autonomic function in patients with nerve afferent problems.
随意肌收缩伴随着交感神经活动的增加。交感皮肤反应（SSR）是一种简单且无创的自主神经评估方法，可反映汗腺的同步活动。我们研究的目的是探讨等长肌肉收缩（IC）与SSR变化之间的可能关系。
在11名健康右利手志愿者中，我们记录了由对侧三头肌不同强度和持续时间的IC（mSSR）诱发的手掌SSR。与腋窝处臂丛神经超强电刺激（eSSR）诱发的SSR相比，我们测量了mSSR的潜伏期、持续时间、波幅、波形和习惯化指数（HI）。
IC开始后平均潜伏期为1.34±0.5秒时总会出现单次mSSR。反应波幅与IC强度呈正相关，而潜伏期和持续时间则不然（r = 0.67；p < 0.001）。与eSSR相比，mSSR的潜伏期更短，持续时间更长，HI更低（方差分析；所有比较p < 0.05）。
由于肌肉传入神经的输入不能解释反应的起始，mSSR可能是与运动指令一起内源性产生的。这一点及其较低的习惯化水平，突出了使用mSSR进行生理和临床研究的可能性，特别是在评估有神经传入问题患者的自主神经功能方面。
