Chrissian S A, Stolov W C, Hongladarom T
Arch Phys Med Rehabil. 1976 Mar;57(3):114-9.
The effect of needle electromyography on serum creatine phosphokinase (CPK) levels has remained unclear despite the diagnostic implications. Serum CPK was serially assayed for changes before and after electromyography (EMG) in two healthy persons and ten persons having low back pain, while they remained at total bed rest. Mean curves showed a peak at 6 hours post-EMG and a return to baseline 48 hours post-EMG. The mean peak value was 1.5 times the baseline. Only one sample exceeded the normal range and it was from a patient with frank positive waves and fibrillation potentials. Correcting for dilution of CPK released, by body weight and for total trauma, by number of needle insertions did not modify the results. The time course and magnitude of elevation of CPK parallel those reported for post exercise changes but are much less than those reported to follow myocardial infarction. In the differential diagnosis of myopathies, care must be taken to ensure that the combination of needle electromyography, exercise, diurnal variation and active denervation does not lead to a "false-positive" elevation of CPK above the normal range. Needle electromyography by itself should not induce a false-positive CPK level in a normal person and no significant changes in CPK levels are likely to occur within two hours after the study.
尽管针极肌电图检查具有诊断意义，但其对血清肌酸磷酸激酶（CPK）水平的影响仍不明确。在两名健康人和十名腰痛患者完全卧床休息期间，对其进行肌电图检查（EMG）前后的血清CPK水平进行了连续检测。平均曲线显示，EMG后6小时出现峰值，48小时后恢复至基线水平。平均峰值为基线值的1.5倍。只有一个样本超过正常范围，该样本来自一名出现明显正锐波和纤颤电位的患者。通过体重校正CPK释放的稀释情况，并通过针插入次数校正总创伤情况，并未改变结果。CPK升高的时间进程和幅度与运动后变化报道的情况相似，但远低于心肌梗死后报道的情况。在肌病的鉴别诊断中，必须注意确保针极肌电图检查、运动、昼夜变化和主动失神经支配等因素的综合作用不会导致CPK出现高于正常范围的“假阳性”升高。针极肌电图检查本身不应在正常人中诱导CPK水平出现假阳性，并且在检查后两小时内CPK水平不太可能发生显著变化。
