Alternations in Circadian Variation in Heart Rate Variability in Patients after Cervical Spinal Injury.

引言：众所周知，颈脊髓损伤患者由于损伤而遭受自主神经系统（ANS）衰竭。手术刺激可触发病变水平以下不受椎管上中枢抑制的交感神经和副交感神经传入神经。这可能导致手术后ANS活动恶化。心率变异性（HRV）的分析可以评估ANS活动的变化。本研究旨在评估全麻下脊柱手术后ANS的活性。方法：经机构批准和知情同意后，对12例患者（ASAPS 1或2）进行评估。对6例颈椎病患者和6例后纵韧带患者行颈椎固定减压术。使用活性示踪剂（AC300, Suwa Trust, Tokyo）对每位患者进行24小时脑电图记录。分别于术前2天（PRE）和术后3天（POD1）、3天（POD3）、7天（POD7）进行测量。功率谱计算采用最大熵法（Memcalc系统，Suwa Trust, Tokyo）。将HRV功率谱划分为高频分量（HF: 0.5 ~ 0.40 Hz）、低频分量（LF:0.04 ~ 0.15 Hz）和比值（HF/LF）两个不同频段。心衰反映迷走神经药物活动，LF反映交感神经和副交感神经的影响。计算LF/HF比值以反映交感神经迷走神经平衡。在基线（PRE）、POD1、POD3和POD7的24小时时段以及白天（8:00-21:00）和夜间（21:00-8:00）对变量进行分析。与基线值的差异采用重复测量单因素方差分析，p < 0.05为显著性。所有数据均以mean±SD表示。结果：与术前相比，夜间、白天和24小时的LF和HF均有所升高。它们在POD3和POD7处减少。术前HRV昼夜变化的减弱在术后一周内恢复。结论：手术和全身麻醉改变了颈脊髓损伤患者的交感神经和副交感神经功能。我们发现，通过比较白天和夜间HRV变量，患者在手术后一周内表现出昼夜节律模式的改变。手术和麻醉引起的ANS活动变化和HRV昼夜变化的作用尚不清楚，需要在颈脊髓损伤患者中进一步研究。少

Introduction : Cervical spinal cord injury patients are known to suffer from the autonomic nervous system (ANS) failure as a result of their injury. Surgical stimulation may trigger sympathetic and parasympathetic afferents below the level of the lesion that are not inhibited by supraspinal centers. This can lead to deteriorate the ANS activity after the surgery. Analysis of the heart rate variability (HRV) can assess the changes in the ANS activity.This study was performed to evaluate the ANS activity after the spinal surgery under the general anesthesia.Method : After institutional approval and informed consent, 12 patients (ASAPS 1 or 2) were evaluated. Cervical fixation and decompression was carried out for six patients with cervical spondylosis and six patient with the posterior longitudinal ligament. Twenty-four hour EEG recordings were obtained for each patients with a active tracer (AC300, Suwa Trust, Tokyo). Measurements were performed on 2 day before surgery (PRE) and postope … More rative -1 (POD1), 3 (POD3), 7 (POD7) days. Power spectra were calculated with a maximum entropy method (Memcalc system, Suwa Trust, Tokyo). The power spectrum of HRV was divided into two different frequency bands : high-frequency component (HF:0.l5-0.40 Hz), low-frequency component (LF:0.04-0.15 Hz), and the ratio(HF/LF). The HF was used to reflect the vagally medicated activity and the LF to reflect both sympathetic and parasympathetic influences. The LF/HF ratio was calculated in order to mirror the sympathovagal balance. The variables were analyzed in 24-hours periods and also in daytime (8:00-21:00) and night-time (21:00-8:00) at baseline (PRE), POD1, POD3, and POD7. Difference from the baseline value were analyzed with repeated measure one-way ANOVA and significance was considered for values of p < 0.05. All data were expressed as mean ± SD.Result : LF and HF in night-time, daytime and 24-hours increased at POD1 as compared to PRE. They decreased at POD3 and POD7. The diminished circadian variation in HRV before surgery recovered within a week after the surgery.Conclusion : These data demonstrate that surgical procedure and general anesthesia altered the sympathetic and parasympathtic function in patients with cervical spinal cord injury. We found by comparing daytime and night-time HRV variables, that patients demonstrated alterations in a pattern of circadian rhythm city within a week after the surgery. The role of the changes in the ANS activity and circadian variations of HRV induced by the surgical procedure and anesthesia is still unclear and further studies will be needed in patients with cervical spinal cord injury. Less