Oluwole O S A, Onabolu A O, Cotgreave I A, Rosling H, Persson A, Link H
Neurology Unit, Department of Medicine, College of Medicine, University of Ibadan, Ibadan, Nigeria.
J Neurol Neurosurg Psychiatry. 2003 Oct;74(10):1417-22. doi: 10.1136/jnnp.74.10.1417.
The occurrence of ataxic polyneuropathy in an endemic area in south west Nigeria has been attributed to exposure to cyanide from cassava foods. However, it has been shown that the prevalence of ataxic polyneuropathy is not high in several communities in the tropics where exposure to cyanide from cassava foods is high.
To determine the incidence of ataxic polyneuropathy in an endemic community, and to compare the intake of cassava foods, exposure to cyanide, and levels of thiols in cases and controls.
A cohort of 3167 healthy subjects aged 10 years and over in Ososa, Nigeria, was followed for two years, screened, and examined neurologically. Ataxic polyneuropathy was diagnosed if sensory polyneuropathy and sensory gait ataxia were both present. Controls were selected randomly within 10 year age groups of subjects who screened negative. Intake of cassava foods, exposure to cyanide, concentrations of thiols (glutathione, cysteine, and gamma glutamylcysteine) in plasma, and visual evoked potentials were measured.
Person-years of follow up were 6246 for 1469 male and 1698 female subjects in the cohort. The incidence of ataxic polyneuropathy was 64 per 10,000 person-years (31 for male and 93 for female subjects). Multivariate odd ratios were 0.78 (95% CI 0.23 to 2.61) for intake of the commonest cassava food, and 1.64 (0.56 to 5.09) for concentration of thiocyanate in plasma. The concentration of thiols was less than the reference limits in two controls, but in none of the cases. The latency of P100 was prolonged in 20 cases (69%) compared with 14 controls (42%) (p<0.05).
The incidence of ataxic polyneuropathy is high in Ososa, Nigeria, but the intake of cassava foods, exposure to cyanide, and levels of thiols, are not related to the occurrence. These findings do not suggest that cyanide is the cause of endemic ataxic polyneuropathy.
在尼日利亚西南部的一个地方病区，共济失调性多发性神经病的发生被归因于食用木薯食物所接触的氰化物。然而，研究表明，在热带地区的几个社区中，尽管食用木薯食物接触氰化物的情况很普遍，但共济失调性多发性神经病的患病率并不高。
确定一个地方病区中共济失调性多发性神经病的发病率，并比较病例组和对照组木薯食物的摄入量、氰化物暴露情况以及硫醇水平。
对尼日利亚奥索萨3167名10岁及以上的健康受试者进行了为期两年的队列研究，进行筛查并进行神经学检查。如果同时存在感觉性多发性神经病和感觉性步态共济失调，则诊断为共济失调性多发性神经病。在筛查为阴性的受试者的10岁年龄组内随机选择对照组。测量木薯食物的摄入量、氰化物暴露情况、血浆中硫醇（谷胱甘肽、半胱氨酸和γ-谷氨酰半胱氨酸）的浓度以及视觉诱发电位。
该队列中1469名男性和1698名女性受试者的随访人年数为6246。共济失调性多发性神经病的发病率为每10000人年64例（男性31例，女性93例）。最常见木薯食物摄入量的多变量比值比为0.78（95%可信区间0.23至2.61），血浆硫氰酸盐浓度的多变量比值比为1.64（0.56至5.09）。两名对照组受试者的硫醇浓度低于参考限值，但病例组中无一例。与14名对照组受试者（42%）相比，20例病例（69%）的P100潜伏期延长（p<0.05）。
在尼日利亚奥索萨，共济失调性多发性神经病的发病率很高，但木薯食物的摄入量、氰化物暴露情况以及硫醇水平与该病的发生无关。这些发现并不表明氰化物是地方性共济失调性多发性神经病的病因。
