Effects of lead and mercury intoxications on evoked potentials

Abstract

Pattern reversal, brain stem auditory and somatosensory evoked potentials (PREPs, BAEPs, SEPs) have been recorded on 13 patients occupationally exposed to inorganic lead compounds, in 9 patients occupationally or accidentally exposed to inorganic mercury compounds and in 26 chronic alcoholics. The results were compared to those of a normal control group. Peripheral conduction velocities were decreased in lead exposed workers and in alcoholics, but not modified in the mercury exposed patients. In the three exposed groups, an amplitude increase (PREPs and upper limb SEP cortical components), more important in the mercury group and an increase of central conduction time in case of lower limb stimulation, could be interpreted as early signs of nervous cortical impairment.

Subclinical Cerebellar Anterior Lobe, Vestibulo-Cerebellar and Spinocerebellar Afferent Effects in Young Female Lead Workers in China: Computerized Posturography with Sway Frequency Analysis and Brainstem Auditory Evoked Potentials.

“…Hirata and Kosaka 8) also observed significant prolongation of the III-V interpeak latency in lead workers. On the other hand, some researchers failed to find significant delays in BAEP latencies in lead workers with mean BPb concentrations of 100 µg/dl 52) and of 41 µg/dl 11) . The effects of lead on the auditory nervous system should be further investigated.…”

Lead (Pb2+) modulation of potassium currents of guinea pig outer hair cells

“…Lead (Pb 2 + ) is an insidious environmental toxicant that causes irreversible medical health effects, including central auditory processing problems [11,29], cognitive dysfunctioning [5], psychologic and classroom deficits [8,31], changes in auditory evoked potentials [15,22,36], and purported decreased hearing sensitivity [35,41,42,44,49]. A blood lead level (BLL) as low as 0.5 AM (10.34 Ag/dl) has been reported to cause decreased hearing sensitivity [44].…”

Subclinical neurophysiological effects of lead: A review on peripheral, central, and autonomic nervous system effects in lead workers

“…All these data suggest that lead affects the optic nerve pathway at a mean BPb above 40 mg/dL in adults. On the other hand, Lille et al [1988] and Murata et al [1995] failed to ®nd any signi®cant prolongation in VEP latency in lead workers. Otto and Fox [1993] described that the effects of lead on VEP latencies do not always accord among study reports.…”