Department of Neurology, Mayo Clinic, Jacksonville, Florida, U.S.A.
J Clin Neurophysiol. 2022 Jul 1;39(5):397-400. doi: 10.1097/WNP.0000000000000790. Epub 2020 Nov 24.
The medial antebrachial cutaneous (MAC) sensory nerve conduction study (NCS) is a technique performed to evaluate for medial cord/lower trunk plexopathies. Low-amplitude responses and muscle artifact pose technical challenges for MAC NCS. To compare the recorded sensory NCS responses using a proximal MAC (pMAC) NCS technique with a distal (dMAC) technique.To compare the recorded sensory NCS responses using a proximal MAC (pMAC) NCS technique with a distal (dMAC) technique.
Adults referred to our neurophysiology laboratory for whom MAC NCS were clinically indicated were included. Medial antebrachial cutaneous NCS were performed using dMAC (stimulating at the elbow) and pMAC (stimulating in upper arm) techniques. Amplitudes and peak latencies were compared.
Forty-eight patients (82 arms: 39 right and 43 left) were studied. The mean amplitude difference (95% confidence interval) in right pMAC over right dMAC was 4.4 μV (range, 2.78-6.09 μV; P < 0.0001) and that of left pMAC over left dMAC was 5.23 μV (range, 3.35-7.12 μV; P < 0.0001).
The pMAC technique recorded larger mean amplitudes than the dMAC technique, which may improve the technical reliability and diagnostic accuracy when identifying plexopathies.
前臂内侧皮神经（MAC）感觉神经传导研究（NCS）是一种用于评估内侧束/下干丛神经病的技术。低幅度反应和肌肉伪迹给 MAC NCS 带来了技术挑战。比较使用近端 MAC（pMAC）NCS 技术与远端（dMAC）技术记录的感觉 NCS 反应。
纳入我院神经生理实验室因临床需要进行 MAC NCS 的成年人。使用 dMAC（肘刺激）和 pMAC（上臂刺激）技术进行前臂内侧皮神经 NCS。比较幅度和峰潜伏期。
共研究了 48 名患者（82 只手臂：39 只右臂和 43 只左臂）。右侧 pMAC 与右侧 dMAC 的平均振幅差（95%置信区间）为 4.4μV（范围，2.78-6.09μV；P<0.0001），左侧 pMAC 与左侧 dMAC 的平均振幅差为 5.23μV（范围，3.35-7.12μV；P<0.0001）。
pMAC 技术记录的平均幅度大于 dMAC 技术，这可能会提高识别丛神经病时的技术可靠性和诊断准确性。
