Spitzer A, Lang E, Birklein F, Claus D, Neundörfer B
Department of Neurology, Erlangen-Nuremberg University, Germany.
Funct Neurol. 1997 May-Aug;12(3-4):115-22.
The aim of our study was to investigate the relationship between cardiac autonomic neuropathy and dysfunction of myelinated and unmyelinated nerve fibres in the peripheral nerve. We measured nerve conduction velocities, warmth/cold perception thresholds at the foot dorsum, sympathetic skin response (SSR), and performed the quantitative sudomotor axon reflex test (QSART). Forty-three diabetic patients with distal-symmetric polyneuropathy were included. According to the results of heart rate variation, 20 patients had cardiac autonomic neuropathy (CAN+). Apart from motor nerve conduction velocities, all tests were more often abnormal in CAN+ patients. Warmth thresholds (afferent C-fibres) and reduced compound muscle action potentials (CMAPs) of the tibial and peroneal nerve, indicating axonal damage, were more often abnormal in CAN+. Cold threshold and sural nerve conduction velocity were indicators of involvement of myelinated small and large nerve fibres, but not of the cardiac autonomic system. Ninety-four percent (94%) of patients with absent SSR and 78% of patients with abnormal QSART had CAN+. SSR and QSART may be useful for assessment of autonomic neuropathy in diabetic patients with cardiac arrhythmia where direct measurement of heart rate variability is not possible. In the majority of our patients with CAN+, the vagal-cardiac and the sudomotor-sympathetic systems were involved simultaneously, although two entirely different systems were tested. This may reflect a C-fibre directed selectivity of the pathological process in autonomic diabetic neuropathy. In conclusion our results show that diabetics with and without cardiac autonomic neuropathy have a different profile of involvement of peripheral nerve fibres.
我们研究的目的是调查心脏自主神经病变与周围神经中有髓和无髓神经纤维功能障碍之间的关系。我们测量了神经传导速度、足背的温/冷感觉阈值、交感神经皮肤反应（SSR），并进行了定量汗腺轴突反射试验（QSART）。纳入了43例患有远端对称性多发性神经病的糖尿病患者。根据心率变异性结果，20例患者存在心脏自主神经病变（CAN+）。除运动神经传导速度外，CAN+患者的所有检查结果更常出现异常。CAN+患者中，温暖阈值（传入C纤维）以及胫神经和腓总神经复合肌肉动作电位（CMAP）降低（提示轴突损伤）更常出现异常。冷阈值和腓肠神经传导速度是有髓小和大神经纤维受累的指标，但不是心脏自主神经系统受累的指标。SSR缺失的患者中有94%以及QSART异常的患者中有78%存在CAN+。对于无法直接测量心率变异性的糖尿病心律失常患者，SSR和QSART可能有助于评估自主神经病变。在我们大多数CAN+患者中，迷走神经-心脏系统和汗腺-交感神经系统同时受累，尽管测试的是两个完全不同的系统。这可能反映了糖尿病自主神经病变病理过程中针对C纤维的选择性。总之，我们的结果表明，有和没有心脏自主神经病变的糖尿病患者，其周围神经纤维受累情况不同。
