P20-S Is it necessary to do bilateral nerve conduction studies for electrodiagnosis of polyneuropathies?

Abstract

Background Nerve conduction studies (NCS), particularly in lower extremities, are essential for diagnosis and classification of polyneuropathies. However, the necessity of performing NCS bilaterally in the diagnostic workup of suspected polyneuropathy is unclear. We aimed in this study to compare the frequency of abnormal NCS parameters in polyneuropathy between right and left lower extremities. Material and methods We included prospectively 313 consecutive patients referred with the suspicion of polyneuropathy. In all patients, peroneal and tibial motor and sural sensory NCS were examined bilaterally. Results were compared to laboratory controls. Results Of 313 patients, 219 (70%) were diagnosed with polyneuropathy (PNP+) and 94 (30%) had the polyneuropathy diagnosis rejected (PNP−). In the PNP+ group, there was no side differences in neither mean distal motor latency, motor conduction velocity, motor amplitude and F-wave latency for peroneal and tibial nerves, nor in sensory conduction velocity and sensory amplitude for the sural nerve (t-test, p 0.05). Conclusions Our study suggests that bilateral NCS in lower extremity motor and sensory nerves may not be necessary in the evaluation of suspected polyneuropathy. Further studies are required to examine the utility of bilateral NCS in the classification of polyneuropathies.