Vucic Steve, Black Kristin, Siao Tick Chong Peter, Cros Didier
Department of Neurology, Massachusetts General Hospital, Bigelow 1256, 55 Fruit Street, Boston, MA 02114, USA.
Clin Neurophysiol. 2006 Feb;117(2):398-404. doi: 10.1016/j.clinph.2005.10.012. Epub 2006 Jan 3.
Cervical nerve root stimulation (CRS) allows the assessment of conduction in the proximal segments of motor fibers destined to the upper extremities, which are not evaluated by routine nerve conduction studies (NCS). Since many primary demyelinating polyneuropathies (PDP) are multifocal lesions may be confined to the proximal nerve segments. CRS may therefore increase the yield of neurophysiologic studies in diagnosing PDP.
We reviewed clinical and neurophysiologic data from 38 PDP patients and compared them to 35 patients with motor neuron disease (MND), and 21 healthy controls (HC).
Mean onset-latency was significantly prolonged in PDP patients. The optimal onset-latency cutoff necessary to distinguish PDP from MND and controls was 17.5 ms for the abductor pollicis brevis (APB) and abductor digiti minimi (ADM), and 7 ms for Biceps and Triceps. Mean reduction in proximal to distal CMAP amplitude to APB and ADM was significantly greater in PDP patients, with an optimal cutoff in proximal to distal CMAP amplitude reduction necessary to distinguish PDP from MND and HC being 45%.
CRS is effective in distinguishing PDP from MND and HC based on prolonged onset latency and conduction block criteria.
CRS may increase the diagnostic yield in cases where demyelinating lesions are confined to the proximal peripheral neuraxis.
颈神经根刺激（CRS）可评估支配上肢的运动纤维近端节段的传导情况，而常规神经传导研究（NCS）无法对其进行评估。由于许多原发性脱髓鞘性多发性神经病（PDP）是多灶性病变，可能局限于神经近端节段。因此，CRS可能会提高神经生理学研究在诊断PDP中的阳性率。
我们回顾了38例PDP患者的临床和神经生理学数据，并将其与35例运动神经元病（MND）患者和21例健康对照（HC）进行比较。
PDP患者的平均起始潜伏期显著延长。区分PDP与MND及对照所需的最佳起始潜伏期临界值，对于拇短展肌（APB）和小指展肌（ADM）为17.5毫秒，对于肱二头肌和肱三头肌为7毫秒。PDP患者APB和ADM近端与远端复合肌肉动作电位（CMAP）波幅的平均降低幅度显著更大，区分PDP与MND及HC所需的近端与远端CMAP波幅降低的最佳临界值为45%。
基于起始潜伏期延长和传导阻滞标准，CRS能有效区分PDP与MND及HC。
在脱髓鞘病变局限于近端周围神经轴的病例中，CRS可能会提高诊断阳性率。
