Objective

To summarize the neurophysiological properties of acute flaccid myelitis (AFM) and evaluate limb-based motor outcomes.

Methods

Nerve conduction studies (NCS) in 49 patients (21 females, 28 males; median age = 52 m) with AFM (median = 7 d after onset; range 1–122 d) were reviewed. Neurophysiological findings, together with treatment and prognosis, and neurophysiology–neuroimaging correlations were analyzed.

Results

The findings indicated that 64% of paralytic limbs during the acute stage (≤14 d after onset) showed diminished or absent compound muscle action potentials (CMAPs), 79% showed normal motor nerve conduction velocities, 55% showed decreased persistence or absent F-waves, and 95% showed normal sensory nerve conduction velocities. The rate of CMAP abnormalities increased from 41% on days 1–2 to 83% on days 13–14. The reduction in CMAP amplitude was correlated with weaker muscle strength at both the peak neurological deficit and the last follow-up. The baseline limb-based muscle strength at nadir and anterior horn-localized magnetic resonance imaging lesions at recovery stage (>14 d) were strong predictors of outcome at the last follow-up.

Conclusions

AFM typically shows neurophysiological features of neuronopathy.

Significance

NCS is probably useful in the diagnosis and evaluation of AFM.

中文翻译：

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急性弛缓性脊髓炎的临床和电生理特征：一项全国队列研究

客观的

总结急性弛缓性脊髓炎 (AFM) 的神经生理学特性并评估基于肢体的运动结果。

方法

对 49 名患者（21 名女性，28 名男性；中位年龄 = 52 米）的 AFM（中位时间 = 发病后 7 天；范围 1-122 天）的神经传导研究 (NCS) 进行了审查。分析了神经生理学发现、治疗和预后以及神经生理学-神经影像学的相关性。

结果

结果表明，在急性期（发病后≤14 d），64%的瘫痪肢体复合肌肉动作电位（CMAPs）减弱或缺失，79%的运动神经传导速度正常，55%的肢体持续性下降或F-缺失。波，95% 显示正常的感觉神经传导速度。CMAP 异常率从第 1-2 天的 41% 增加到第 13-14 天的 83%。CMAP 振幅的降低与神经功能缺损峰值和最后一次随访时肌肉力量减弱有关。在恢复阶段（> 14 天）的最低点基线基于肢体的肌肉力量和前角定位的磁共振成像病变是最后一次随访结果的强预测因子。

结论

AFM 通常显示神经元病的神经生理学特征。

意义

NCS 可能对 AFM 的诊断和评估有用。