Study Of Electromyography In POEMS Syndrome

Poems syndrome is a multisystemic disorder disease characterized by polyneuropathy, organomegaly, endocrinopathy, monoc lonal gammopathy, and skin changes. That is the way the disease is named. The pathogenesis is not well understood yet. Polyneuropathy is one of the major criteria and it is necessary in diagnose, which explains why many patients are found in neuropathy department. So it is necessary to analyse and learn the electromyography results of these patients.Objective:to provide clues in the diagnose of the poems syndrome by analyzing the electroneurophysiology characters of8patients who have been diagnosed as poems syndrome in recent years in our hospital.Method:We studied8cases with POEMS and8cases of age-matched healthy subjects.Electromyologram was measured with the KEYPOINT myoelectric/evoked potential instrument.1. DML, MCV, CMAP:The recording electrode was placed over the muscle belly and the reference electrode was placed distsllv over the muscle tendon. The stimulating electrode was placed over the nerve with the cathode close to the recording electrode and the nerve was stimulated orthodromically. The current was increased until the CMAP no longer increased, then stimulation was increased by further20%-30%. CMAP was recorded with surface disc electrode and its latency and amplitude were analysed. The stimulation was on both distal and lateral point, so the MCV could be analysed.2. SNAP, SCV:SNAP was recorded by stimulation of the distal sensory fibers in the orthodromic sensory conduction test with the recording electrode placed close to the stimulator and its amplitude and SCV were analyzed.3. The F-wave:The F-wave latency was obtained by stimulating the distal portion of the median nerve, ulnar nerve, tibia nerve and peroneal nerve, using motor nerve conduction setups.4. RNS:ulnar nerve was chosen to be stimulated by both low (3Hz、5Hz) and high (10Hz、15Hz、2OHz) frequency, and to observe the changes of amplitude.5. Needle electromyography:EMG was performed by insertion of a concentric needle in muscle belly. Recordings were made from each muscle at rest, during slight and maximal voluntary contraction. Spontaneous activity and motor unit potentials were analysed.Result1. In compared patients, the distal motor latency were prolonged, motor nerve conduct velocity and amplitude were decreased(P<0.05).2. Sensory nerve conduct velocity and amplitude were decreased(P<0.05).3. The latency of F wave is prolonged and the amplitude of F wave is decreased 4. The abnormal rate of motor nerve is93.75%, while the sensory nerve is87.5%, P>0.05; The abnormal rate of motor nerve in2the upper limbs and lower limbs is different, but P>0.05.5. The abnormal rate of sensory nerve in the upper limbs and lower limbs is different, P<0.05.6. The repetitive nerve stimulation in ulnar nerves shows negative results. The electromyography in abductor pollicis brevis and anterior tibial muscle shows no spontaneous potentials and only one patients’anterior tibial muscle shows simple phase in recruited activity. The duration of motor unit potential (MUP) is prolonged and amplitude is increased, but in abductor pollicis brevis, P>0.05, and in anterior tibial, P<0.05.Conclusion1. the characters of poems syndrome’polyneuropathy includes impairment of both sensory and motor systems; the conduct velocity and amplitude were both decreased, and it is particularly obvious in lower limbs.2. the abnormal F wave implys the impairment in the proximal part of nerve.3. The abnormal rates in electromyography is relatively low, and the results suggested that we should focus on the examination of anterior tibial for suspected POEMS patients.4. RNS shows negative results.