study observed the normal nerve conduction parameters in population of Haryana
to provide reference values in our electrophysiology laboratory. Most of
studies have been done but on limited subjects of convenience including
students, staff and other workers,8-11 because of small sample size
statistical power in these studies was lacking. In contrast to above mentioned
convenient sampling procedure for determining the normative data a community
sampling was necessary. In our study a large spectrum of population coming from
different parts of State of Haryana was studied.
temperature control is also an important aspect which was well taken care in
our study as the limb temperature was kept between 30-35 0 C.
our study there was no significant difference of gender in the different nerve
conduction study parameters like Latency, duration, amplitude and conduction
velocity as mentioned by many other authors.12-15 however we
disagree with the studies showing effect of gender on these parameters16,17
mainly latency and conduction velocity. Buschbacher18 and D. Anton
et al19 noted difference in latency more in males as compared to
females but the age group studied in those studies was more than 50 years. 18,
latency of median nerve in our study was 7.39 ms, SD 1.32 which was not in congruent
with the other studies.21,23,24 This may be because of
instrumentation and procedure of recording the same i.e. 8 cm technique or
of nerve conduction was 13.62 ms, SD 3.69 in our study. Nowhere in literature
had we found normative data of duration of median motor nerve study to compare
of median nerve in our study was 9.48 mV, SD 5.22 which was similar to study
done 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 and
Mcdougal22 (12.1mV, SD 3.8) showed higher amplitude in their study,
this difference may be because of short sample size in these studies. While
studies by Kimura23 (7 mV, SD 3) and Owolabi et al24 (7.7
mV, SD 2) showed lesser amplitude.
velocity of median nerve in our study was 58.61 m/s, SD 5.51. Our findings were
similar 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 higher
To find out whether
the value derived from the median nerve study in a person from a particular
population is normal or not is dependent on what is accepted value range of
that population. The normative value generated of median nerve study is
dependent on the demographic profile of the subjects being tested. This study
has tried to bring normative data from the population of State of Haryana,
India with a mindset that these values will be helpful in making clinical
decisions with regards to the patients.Introduction
conduction studies (NCS) are done to evaluate peripheral nerve functions. NCS
may be used for diagnosis as well as prognosis of peripheral nerve disorders.1-6
is influenced by various factors such as age, gender, temperature, height and
years various electrophysiology laboratories are using standard values used by
developed countries like US, Canada and Europe to diagnose different
neurological problems as normative data for their population is not available
in the literature. This study has been devised to find the normative data of
population of Haryana, India so that a fruitful comparison may be made for
diagnosis of peripheral nerve diseases.
Material and Methods
was conducted on the patients attending the electrophysiology laboratory of
PGIMS Rohtak from different areas of State of Haryana. A total of 330 median
nerves 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 of
167 right sided 111 were of males and 56 of females. A total of 116 female
nerves and 214 male nerves were studied.
criteria: History of neuromuscular disease, cardiac pacemaker, diabetes
mellitus, B12 or folate deficiency, thyroid disorder, any neck or back surgery,
rediculopathy, peripheral neuropathy, alcoholism, entrapment syndrome,
chemotherapy, medication for any disease.
healthy individuals or patients with acute nerve injury on contralateral limbs
not on any medications were included in the study.