Hilz M J, Kolodny E H, Neuner I, Stemper B, Axelrod F B
Department of Neurology, New York University Medical Center, NY 10016, USA.
J Neurol Neurosurg Psychiatry. 1998 Sep;65(3):338-43. doi: 10.1136/jnnp.65.3.338.
Patients with familial dysautonomia have an increased risk of sudden death. In some patients with familial dysautonomia, sympathetic cardiac dysfunction is indicated by prolongation of corrected QT (QTc) interval, especially during stress tests. As many patients do not tolerate physical stress, additional indices are needed to predict autonomic risk. In familial dysautonomia there is a reduction of both sympathetic neurons and peripheral small nerve fibres which mediate temperature perception. Consequently, quantitative thermal perception test results might correlate with QTc values. If this assumption is correct, quantitative thermotesting could contribute to predicting increased autonomic risk.
To test this hypothesis, QTc intervals were determined in 12 male and eight female patients with familial dysautonomia, aged 10 to 41 years (mean 21.7 (SD 10.1) years), in supine and erect positions and postexercise and correlated with warm and cold perception thresholds assessed at six body sites using a Thermotest.
Due to orthostatic presyncope, six patients were unable to undergo erect and postexercise QTc interval assessment. The QTc interval was prolonged (>440 ms) in two patients when supine and in two additional patients when erect and postexercise. Supine QTc intervals correlated significantly with thermal threshold values at the six body sites and with the number of sites with abnormal thermal perception (Spearman's rank correlation p<0.05). Abnormal Thermotest results were more frequent in the four patients with QTc prolongation and the six patients with intolerance to stress tests.
The results suggest that impaired thermal perception correlates with cardiac sympathetic dysfunction in patients with familial dysautonomia. Thus thermotesting may provide an alternative, albeit indirect, means of assessing sympathetic dysfunction in autonomic disorders.
家族性自主神经功能异常患者猝死风险增加。在一些家族性自主神经功能异常患者中，校正QT（QTc）间期延长提示交感神经心脏功能障碍，尤其是在压力测试期间。由于许多患者无法耐受身体应激，因此需要额外的指标来预测自主神经风险。在家族性自主神经功能异常中，介导温度感知的交感神经元和外周小神经纤维均减少。因此，定量热觉测试结果可能与QTc值相关。如果这一假设正确，定量热测试可能有助于预测自主神经风险增加。
为验证这一假设，对12名男性和8名女性家族性自主神经功能异常患者（年龄10至41岁，平均21.7（标准差10.1）岁）进行仰卧位、直立位及运动后QTc间期测定，并将其与使用热觉测试在六个身体部位评估的冷热感知阈值相关联。
由于体位性晕厥前期，6名患者无法进行直立位及运动后QTc间期评估。两名患者仰卧位时QTc间期延长（> 440毫秒），另外两名患者直立位及运动后QTc间期延长。仰卧位QTc间期与六个身体部位的热阈值以及热觉异常部位的数量显著相关（Spearman等级相关性p<0.05）。在QTc延长的4名患者和对应激测试不耐受的6名患者中，热觉测试异常结果更为常见。
结果表明，家族性自主神经功能异常患者的热觉受损与心脏交感神经功能障碍相关。因此，热测试可能提供一种评估自主神经疾病中交感神经功能障碍的替代方法，尽管是间接的。
