Yokoyama K, Araki S, Murata K, Morita Y, Katsuno N, Tanigawa T, Mori N, Yokota J, Ito A, Sakata E
Department of Public Health, Faculty of Medicine, University of Tokyo, Japan.
Neurotoxicology. 1997;18(2):371-80.
By computerized static posturography, the subclinical effects of past and concurrent lead absorption on the vestibulo-cerebellum (lower vermis), anterior cerebellar lobe and spinocerebellar afferent pathway were examined in 49 male chemical factory workers exposed to lead stearate (lead workers). Their concurrent blood lead (BPb) concentrations ranged from 7 to 36 (mean 18.0) microgram/100 g. In the past, their maximum BPb ranged from 11 to 113 (mean 47.7) micrograms/100 g; mean BPb was 7-52 (mean 23.5) micrograms/100 g; and cumulative BPb, defined as mean BPb x years of exposure, was 15-1268 (mean 390.6) micrograms.year/100 g. Control subjects were 23 healthy male workers who had never been occupationally exposed to lead. The postural sway of high (2-4 Hz) and low (1 Hz or less) frequencies with eyes open for lead workers was significantly greater than that for controls in the medio-lateral (right-left) and anterior-posterior directions. Similarly, the sway of high and low frequencies with eyes closed was significantly larger in lead workers than in controls in the medio-lateral direction. Results of stepwise multiple regression analysis indicated that the sway with frequencies of 0.5-2 Hz with eyes open was related to concurrent BPb in the anterior-posterior direction. With eyes closed the sway of high frequency was significantly related to mean BPb in the past in the medio-lateral direction. The pattern of the changes suggests that the vestibulo-cerebellum, anterior cerebellar lobe and spinocerebellar pathway are asymptomatically affected by lead. It appears that the change in the vestibulo-cerebellum reflects concurrent lead absorption, while on the other hand, that in the anterior cerebellar lobe reflects past lead absorption.
通过计算机化静态姿势描记法，对49名接触硬脂酸铅的男性化工厂工人（铅作业工人）过去和同时期铅吸收对前庭小脑（小脑蚓部下部）、小脑前叶和脊髓小脑传入通路的亚临床影响进行了检查。他们同时期的血铅（BPb）浓度范围为7至36（平均18.0）微克/100克。过去，他们的最高BPb范围为11至113（平均47.7）微克/100克；平均BPb为7至52（平均23.5）微克/100克；累积BPb定义为平均BPb×接触年限，范围为15至1268（平均390.6）微克·年/100克。对照组为23名从未职业性接触过铅的健康男性工人。铅作业工人睁眼时高频率（2 - 4赫兹）和低频率（1赫兹及以下）的姿势摆动在内外侧（左右）和前后方向上均显著大于对照组。同样，铅作业工人闭眼时高频率和低频率的摆动在内外侧方向上也显著大于对照组。逐步多元回归分析结果表明，睁眼时频率为0.5 - 2赫兹的摆动在前后方向上与同时期的BPb有关。闭眼时，高频率摆动在内外侧方向上与过去的平均BPb显著相关。这些变化模式表明，前庭小脑、小脑前叶和脊髓小脑通路受到铅的无症状影响。似乎前庭小脑的变化反映了同时期的铅吸收，而另一方面，小脑前叶的变化反映了过去的铅吸收。
