If the NCV is normal along the length of the peripheral nerve,yet the amplitude of the electromyogram (EMG)potential is decreased,the disorder is:

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Quizplus · Accepted Answer

Axonopathy reduces both the amplitude and velocity of recorded potentials during a nerve conduction velocity study.Traumatic myelinopathy causes decreased velocity but usually not amplitude of recorded potentials.Myopathy only affects muscle and so amplitude of recorded potentials is decreased but velocity of conduction is normal.Myasthenia gravis damages ACh receptors on the muscle membrane,so conduction velocity is normal but recorded amplitude decreases with repeated muscle contractions.Because NCV studies only test peripheral nerves,NCV studies are normal in UMN lesions.

If the NCV Is Normal Along the Length of the Peripheral