Le Pera D, Valeriani M, Tonali P, Restuccia D
Department of Neurology, Università Cattolica del Sacro Cuore, Roma, Italy.
Neurophysiol Clin. 1998 Jun;28(3):221-9. doi: 10.1016/S0987-7053(98)80113-5.
Scalp somatosensory evoked potentials (SEP) to dermatomal stimulation have so far proved to be only partially useful in the diagnosis of monoradiculopathy, mostly in cases without motor impairment. The aim of our study was to test the sensitivity of the spinal N13 potential in uncovering lesions of single cervical roots. We studied five patients suffering from cervical monoradiculopathy, using a recording technique allowing specific recording of the genuine N13 potential which is probably generated by dorsal horn cells. No patient showed signs of muscle impairment and needle EMG was always normal. In four patients, the N13 SEP was absent following stimulation of the dermatome corresponding to the damaged root, while both the lemniscal P14 and the cortical N20 components were normal. SEP recorded after stimulation of upper limb troncular nerves showed no abnormality in all patients. Our findings suggest that the N13 potential, the loss of which after dermatomal stimulation could be due to deafferentation of dorsal horn neurones, is particularly sensitive to initial root compression. Therefore, our montage allowing analysis of the genuine N13 SEP can improve the sensitivity of dermatomal SEP recording in patients with cervical monoradiculopathies.
迄今为止，头皮体感诱发电位（SEP）对皮节刺激的反应在单神经根病的诊断中仅部分有用，主要适用于无运动功能障碍的病例。我们研究的目的是测试脊髓N13电位在发现单根颈神经根病变方面的敏感性。我们研究了5例患有颈单神经根病的患者，采用一种记录技术，能够特异性记录可能由背角细胞产生的真正N13电位。所有患者均无肌肉功能障碍的体征，针极肌电图始终正常。在4例患者中，刺激与受损神经根对应的皮节时，N13 SEP缺失，而薄束核P14和皮层N20成分均正常。刺激上肢干神经后记录的SEP在所有患者中均未显示异常。我们的研究结果表明，N13电位在皮节刺激后消失可能是由于背角神经元传入阻滞，它对早期神经根受压特别敏感。因此，我们能够分析真正N13 SEP的记录方式可提高颈单神经根病患者皮节SEP记录的敏感性。
