Nerve Conduction Velocity

Nerve Conduction Velocity What are the three categories of peripheral neuropathy? - ANS 1. traumatic mononeuropathy 2. multiple mononeuropathy 3. polyneuropathy What are three types of traumatic mononeuropathy? - ANS 1. traumatic myelinopathy (class I) 2. traumatic axonopathy (class II) 3. traumatic severance (class III) What is damaged with traumatic neuropathy? - ANS the myelin sheath at one site When myelin is removed with traumatic myelinopathy what can sometimes be laid down instead? - ANS modality-gated and ligand-gated What kind of traumatic mononeuropathy damages the axon and myelin sheath but spares the layers covering the axon? - ANS traumatic axonopathy What kind of traumatic mononeuropathy damages all parts of a nerve (axon, myelin sheath, layers)? - ANS traumatic severance What diameter axons are the first to fail when they are compressed and suffer anoxia and/or hypoxia? - ANS larger What do compressive forces due to oxygen supply to nerves? - ANS reductions leads to hypoxia and/or anoxia Why do you have to wait 2-3 weeks before performing a electrophysiological exam? - ANS you have to wait until Wallerian degeneration is complete (might get a false positive) What are two types of electrophysiological exams? - ANS 1. nerve conduction velocity 2. needle EMG What is a compound muscle action potential? - ANS summation of a group of almost simultaneous action potentials from several muscle fibers in the same area. What are two different denervation potentials from increased insertional activity? - ANS 1. positive short wave 2. fibrillations potential What are nascent units? - ANS Small amplitude short duration units with decreased recruitment What is the purpose of NCV? - ANS assess the time and quality of conduction of neural impulses in peripheral motor and sensory nerves Are NCV testing diagnostic alone? - ANS no, just another part of comprehensive evaulation Are NCV test evoked or voluntary? - ANS evoked What are commonly test nerves using NCV? - ANS Median Ulnar Peroneal Posterior Tibial What age populations have slower conduction velocities? - ANS infants, children, and elderly adults What effect does cold temperature have on nerve conduction velocity? - ANS slows it down Does oxygenation of a nerve have a direct or inverse relationship with nerve conduction velocity? - ANS direct