IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) e-ISSN: 2279-0853, p-ISSN: 2279-0861.Volume 17, Issue 2 Ver. 2 February. (2018), PP 77-84 www.iosrjournals.org DOI: 10.9790/0853-1702027784 www.iosrjournals.org 77 | Page Measurement of nerve conduction study in a sample of healthy Iraqi: Normative data FarisKadhim Khadir 1 , Najeeb Hassan Mohammad 2 1 (Department of Medical Physiology, College of Medicine, Baghdad University, Iraq) 2 (Department of Medical Physiology, College of Medicine, Baghdad University, Iraq) Correspondance Author; FarisKadhim Khadir Abstract: Electrophysiological study (nerve conduction study”NCS”) is useful adjunct test to the medical history and clinical examination in the diagnosis of such complication, early detection and differentiation of type of peripheral neuropathy. The aims of this study are designed to Decide the most necessary parameters of NCS of healthy subjects to establish the normal electrophysiological values of the common nerves in upper and lower limb .The present study was carried out at the neurophysiology unit in Al-yarmouk Teaching Hospital.The study group consists of eighty six (86) healthy volunteers (45 males and 41 females). The age of this group ranged between 20 to 75 years with a mean (52.48 ±10.63) years. All subjects were healthy and symptoms free, with no history of systemic and neurological diseases. No history of alcohol abuse or drug intake. They compromised normal relatives, medical staff, students and workers. All of 86 subjects that were included in this study were informed about the aim and technique of the study and their acceptance was taken. Each subject was submitted to medical history and electrophysiological tests (NCS) of the two limbs i.e. the upper and the lower. These tests include Sensory nerve conducting study (SNCS) for Median, Ulner and Sural nerves and Motor nerve conducting study (MNCS) for Median, Ulnar, Fibular (Common peroneal), and tibialnerves. The results showed data were processing separately between males and females with mean accompanying with standard deviation for sensory and motor of median, ulnar sural, common peroneal and tibialnerves. Conclusion: The study will be helpful normative parameters of the common tested nerves of the upper and lower limbs were established for the EMG laboratory in our region. Keywords: Iraqis, Lower limbs, Nerves Conduction study, Upper limbs --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 16-01-2018 Date of acceptance: 09-02-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction The NCS tests are typical for the diagnosis of large fiber polyneuropathy .Their usefulness are to Recognize which type of fiber involved ("motor versus sensory") ,Determine the neuropathy severity ,Detect "the distribution of neuropathic dysfunction" (proximal or distal, focal, multifocal or generalized) also Can verify the close amount of axonopathy versus myelinopathy (uniform or patchy demyelination). However, the ultimate electrodiagnosis can only be achieved when the whole prototypes of NCS-EMG result is processed and then perceived with knowledge of the clinical history and examination [1]. Sensory nerve conduction study: The "sensory nerve action potential (SNAP)", is the amount of the accomplishment of potentials created by the myelinated axons of the sensory nerve". The major constituents of "the SNAP are generated by fast conducting A (alpha) fibers with diameters exceeding 9 μm and conductive velocity CV between 40 and 65 m/s in the upper and lower extremities [2 and 3].The parameters of sensory nerve conduction study include: 1-Latency: The latency of SNAP allude to the time exerted to the stimulate moving from the stimulation site to the recording site. Latency is calculated to the onset of the negativity, regardless of whether there is an initial positivity [4]. Latency to the onset reflects conduction in the fastest fibers and is used to calculate conduction velocity, this is called onset latency [5]. 2-Amplitude: The amplitude of SNAP is detected from the peak of the positive deflection to the peak of the negative deflection (peak to peak), it is measured in microvolts (μv). The amplitude relys on the amount of stimulated axons "and the synchrony with which they transmit their impulse[4] 3- Conductive velocity: Represents the space between the stimulation site and that of recording, over the time between stimulation and the arrival of the action potentials at the recording site[6].In sensory studies, the velocity of conduction can be