بررسي تاثير طولاني مدت سرب بر يافته هاي الكترونوروگرافيك اعصاب اندام فوقاني در افراد بدون علامت در معرض سرب

Subclinical Long Term effect of Lead on the Eleetroneurographic Findings of Upper Limb Nerves in Lead - Exposed Subjects

One of the most common heavy metal compounds is lead which has maleffects on different organs such as central and autonomous nervous systems and furthermore causes peripheral neuropathy. Lead can induce electroneurographic variations without clinical symptoms and signs. The aim of this study is determination of these variations in lead - exposed individuals. Fifty six workers who had chronic exposure to lead and no clinical symptoms and signs were assessed for blood lead concentration and motor and sensory nerve conduction velocities (M & S NCVs) and motor latency at upper limb nerves: ulnar, median and radial. The mean SNCVs of ulnar (50.83 m/s) and median (50.81 m/s) was significantly lower than those of control group (P<0.000). There were no significant differences between the two groups in other electroneurographic parameters. Also no correlation was found between blood concentration and electroneurographic findings. According to the results of this study, decrease of distal SNCVs of ulnar and median can be the first sign of lead effcet on the peripheral nerves of upper limb in chronic state. Finally, we recommend using of these electroneurographic tests in individuals exposed to lead at the begining of employ ment for reference test and during employ ment for the evaluation of lead effects as well.