Menon Parvathi, Vucic Steve
Department of Neurology, Westmead Hospital; Sydney Medical School, University of Sydney, Australia.
Department of Neurology, Westmead Hospital; Sydney Medical School, University of Sydney, Australia;
J Vis Exp. 2014 Mar 4(85):51056. doi: 10.3791/51056.
The split hand phenomenon refers to predominant wasting of thenar muscles and is an early and specific feature of amyotrophic lateral sclerosis (ALS). A novel split hand index (SI) was developed to quantify the split hand phenomenon, and its diagnostic utility was assessed in ALS patients. The split hand index was derived by dividing the product of the compound muscle action potential (CMAP) amplitude recorded over the abductor pollicis brevis and first dorsal interosseous muscles by the CMAP amplitude recorded over the abductor digiti minimi muscle. In order to assess the diagnostic utility of the split hand index, ALS patients were prospectively assessed and their results were compared to neuromuscular disorder patients. The split hand index was significantly reduced in ALS when compared to neuromuscular disorder patients (P<0.0001). Limb-onset ALS patients exhibited the greatest reduction in the split hand index, and a value of 5.2 or less reliably differentiated ALS from other neuromuscular disorders. Consequently, the split hand index appears to be a novel diagnostic biomarker for ALS, perhaps facilitating an earlier diagnosis.
裂手现象指的是大鱼际肌的主要萎缩，是肌萎缩侧索硬化症（ALS）的早期特异性特征。一种新的裂手指数（SI）被开发出来以量化裂手现象，并在ALS患者中评估其诊断效用。裂手指数通过将记录在拇短展肌和第一背侧骨间肌上的复合肌肉动作电位（CMAP）幅度的乘积除以记录在小指展肌上的CMAP幅度得出。为了评估裂手指数的诊断效用，对ALS患者进行了前瞻性评估，并将其结果与神经肌肉疾病患者进行比较。与神经肌肉疾病患者相比，ALS患者的裂手指数显著降低（P<0.0001）。肢体起病的ALS患者裂手指数降低最为明显，5.2或更低的值能够可靠地将ALS与其他神经肌肉疾病区分开来。因此，裂手指数似乎是一种新的ALS诊断生物标志物，可能有助于早期诊断。
