Thisstudy observed the normal nerve conduction parameters in population of Haryanato provide reference values in our electrophysiology laboratory. Most ofstudies have been done but on limited subjects of convenience includingstudents, staff and other workers,8-11 because of small sample sizestatistical power in these studies was lacking. In contrast to above mentionedconvenient sampling procedure for determining the normative data a communitysampling was necessary. In our study a large spectrum of population coming fromdifferent parts of State of Haryana was studied. Limbtemperature control is also an important aspect which was well taken care inour study as the limb temperature was kept between 30-35 0 C. Inour study there was no significant difference of gender in the different nerveconduction study parameters like Latency, duration, amplitude and conductionvelocity as mentioned by many other authors.12-15 however wedisagree with the studies showing effect of gender on these parameters16,17mainly latency and conduction velocity.
Buschbacher18 and D. Antonet al19 noted difference in latency more in males as compared tofemales but the age group studied in those studies was more than 50 years. 18,19Distallatency of median nerve in our study was 7.39 ms, SD 1.32 which was not in congruentwith the other studies.
21,23,24 This may be because ofinstrumentation and procedure of recording the same i.e. 8 cm technique orlandmark technique.Durationof nerve conduction was 13.62 ms, SD 3.69 in our study. Nowhere in literaturehad we found normative data of duration of median motor nerve study to comparewith.
Amplitudeof median nerve in our study was 9.48 mV, SD 5.22 which was similar to studydone by Robinson et al20 (9.
5mV, SD 2.9) and Falco et al21 (9.2mV, SD 3.1).Studies by Hennessey et al15 (12.1mV, SD 3.8), Magladery andMcdougal22 (12.1mV, SD 3.
8) showed higher amplitude in their study,this difference may be because of short sample size in these studies. Whilestudies by Kimura23 (7 mV, SD 3) and Owolabi et al24 (7.7mV, SD 2) showed lesser amplitude.Conductionvelocity of median nerve in our study was 58.61 m/s, SD 5.
51. Our findings weresimilar to that of Hennessey and Falco15 (57 m/s, SD 5), Kimura23(57.7 m/s, SD 4.9), Mishra and Kalitha25 (58.52 m/s, SD 8.3).
However study by Owolabi et al24 (62.5m/s SD 4.9) showed higherconduction velocity. ConclusionTo find out whetherthe value derived from the median nerve study in a person from a particularpopulation is normal or not is dependent on what is accepted value range ofthat population. The normative value generated of median nerve study isdependent on the demographic profile of the subjects being tested. This studyhas tried to bring normative data from the population of State of Haryana,India with a mindset that these values will be helpful in making clinicaldecisions with regards to the patients.IntroductionNerveconduction studies (NCS) are done to evaluate peripheral nerve functions. NCSmay be used for diagnosis as well as prognosis of peripheral nerve disorders.
1-6NCSis influenced by various factors such as age, gender, temperature, height andweight.7Foryears various electrophysiology laboratories are using standard values used bydeveloped countries like US, Canada and Europe to diagnose differentneurological problems as normative data for their population is not availablein the literature. This study has been devised to find the normative data ofpopulation of Haryana, India so that a fruitful comparison may be made fordiagnosis of peripheral nerve diseases. Material and MethodsStudywas conducted on the patients attending the electrophysiology laboratory ofPGIMS Rohtak from different areas of State of Haryana. A total of 330 mediannerves observed, out of which 163 were of left side and 167 were on right side.
Out of 163 of left side 103 were of males and 60 were of females while out of167 right sided 111 were of males and 56 of females. A total of 116 femalenerves and 214 male nerves were studied. Exclusioncriteria: History of neuromuscular disease, cardiac pacemaker, diabetesmellitus, B12 or folate deficiency, thyroid disorder, any neck or back surgery,rediculopathy, peripheral neuropathy, alcoholism, entrapment syndrome,chemotherapy, medication for any disease.Onlyhealthy individuals or patients with acute nerve injury on contralateral limbsnot on any medications were included in the study.
