Skip to main content
PMC home page
Journal of Neurology, Neurosurgery, and Psychiatry logoLink to Journal of Neurology, Neurosurgery, and Psychiatry
. 2003 Oct;74(10):1417–1422. doi: 10.1136/jnnp.74.10.1417

Incidence of endemic ataxic polyneuropathy and its relation to exposure to cyanide in a Nigerian community

O Oluwole 1, A Onabolu 1, I Cotgreave 1, H Rosling 1, A Persson 1, H Link 1
PMCID: PMC1757397  PMID: 14570837

Abstract

Background 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.

Objectives 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.

Methods 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 γ glutamylcysteine) in plasma, and visual evoked potentials were measured.

Results 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).

Conclusions 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.

Full Text

The Full Text of this article is available as a PDF (370.1 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Cabre P., Smadja D., Cabié A., Newton C. R. HTLV-1 and HIV infections of the central nervous system in tropical areas. J Neurol Neurosurg Psychiatry. 2000 May;68(5):550–557. doi: 10.1136/jnnp.68.5.550. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Cotgreave I. A., Moldéus P. Methodologies for the application of monobromobimane to the simultaneous analysis of soluble and protein thiol components of biological systems. J Biochem Biophys Methods. 1986 Nov;13(4-5):231–249. doi: 10.1016/0165-022x(86)90102-8. [DOI] [PubMed] [Google Scholar]
  3. Davis R. H., Elzubeir E. A., Craston J. S. Nutritional and biochemical factors influencing the biological effects of cyanide. Ciba Found Symp. 1988;140:219–231. doi: 10.1002/9780470513712.ch13. [DOI] [PubMed] [Google Scholar]
  4. Foss O. P., Lund-Larsen P. G. Serum thiocyanate and smoking: interpretation of serum thiocyanate levels observed in a large health study. Scand J Clin Lab Invest. 1986 May;46(3):245–251. doi: 10.3109/00365518609083666. [DOI] [PubMed] [Google Scholar]
  5. Galanti L. M. Specificity of salivary thiocyanate as marker of cigarette smoking is not affected by alimentary sources. Clin Chem. 1997 Jan;43(1):184–185. [PubMed] [Google Scholar]
  6. Jackson A. A. Human protein requirement: policy issues. Proc Nutr Soc. 2001 Feb;60(1):7–11. doi: 10.1079/pns200065. [DOI] [PubMed] [Google Scholar]
  7. Lundquist P., Kågedal B., Nilsson L. An improved method for determination of thiocyanate in plasma and urine. Eur J Clin Chem Clin Biochem. 1995 Jun;33(6):343–349. doi: 10.1515/cclm.1995.33.6.343. [DOI] [PubMed] [Google Scholar]
  8. Lundquist P., Mårtensson J., Sörbo B., Ohman S. Turbidimetry of inorganic sulfate, ester sulfate, and total sulfur in urine. Clin Chem. 1980 Jul;26(8):1178–1181. [PubMed] [Google Scholar]
  9. MONEKOSSO G. L., ANNAN W. G. CLINICAL EPIDEMIOLOGICAL OBSERVATIONS ON AN ATAXIC SYNDROME IN WESTERN NIGERIA. Trop Geogr Med. 1964 Dec;16:316–323. [PubMed] [Google Scholar]
  10. MONEY G. L. Clinical aspects of tropical ataxic neuropathies related to malnutrition. West Afr Med J. 1959 Feb;8(1):3–17. [PubMed] [Google Scholar]
  11. MONEY G. L. Endemic neuropathies in the Epe district of Southern Nigeria. West Afr Med J. 1958 Mar;7(1):58–62. [PubMed] [Google Scholar]
  12. MONEY G. L., SMITH A. S. Nutritional spinal ataxia. West Afr Med J. 1955 Sep;4(3):117–123. [PubMed] [Google Scholar]
  13. Monekosso G. L., Wilson J. Plasma thiocyanate and vitamin B12 in Nigerian patients with degenerative neurological disease. Lancet. 1966 May 14;1(7446):1062–1064. doi: 10.1016/s0140-6736(66)91009-9. [DOI] [PubMed] [Google Scholar]
  14. Oluwole O. S. A., Onabolu A. O., Cotgreave I. A., Rosling H., Persson A., Link H. Low prevalence of ataxic polyneuropathy in a community with high exposure to cyanide from cassava foods. J Neurol. 2002 Aug;249(8):1034–1040. doi: 10.1007/s00415-002-0779-0. [DOI] [PubMed] [Google Scholar]
  15. Oluwole O. S. A., Onabolu A. O., Sowunmi A. Exposure to cyanide following a meal of cassava food. Toxicol Lett. 2002 Sep 5;135(1-2):19–23. doi: 10.1016/s0378-4274(02)00232-1. [DOI] [PubMed] [Google Scholar]
  16. Oluwole O. S., Onabolu A. O., Link H., Rosling H. Persistence of tropical ataxic neuropathy in a Nigerian community. J Neurol Neurosurg Psychiatry. 2000 Jul;69(1):96–101. doi: 10.1136/jnnp.69.1.96. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Onabolu A. O., Oluwole O. S. A., Bokanga M. Loss of residual cyanogens in a cassava food during short-term storage. Int J Food Sci Nutr. 2002 Jul;53(4):343–349. doi: 10.1080/09637480220138151. [DOI] [PubMed] [Google Scholar]
  18. Onabolu A. O., Oluwole O. S., Bokanga M., Rosling H. Ecological variation of intake of cassava food and dietary cyanide load in Nigerian communities. Public Health Nutr. 2001 Aug;4(4):871–876. doi: 10.1079/phn2001127. [DOI] [PubMed] [Google Scholar]
  19. Osuntokun B. O., Aladetoyinbo A., Bademosi O. Vitamin B nutrition in the Nigerian tropical ataxic neuropathy. J Neurol Neurosurg Psychiatry. 1985 Feb;48(2):154–156. doi: 10.1136/jnnp.48.2.154. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Osuntokun B. O., Aladetoyinbo A. Urinary methylmalonic acid in tropical ataxic neuropathy. Lancet. 1972 Dec 23;2(7791):1376–1377. doi: 10.1016/s0140-6736(72)92832-2. [DOI] [PubMed] [Google Scholar]
  21. Osuntokun B. O. An ataxic neuropathy in Nigeria. A clinical, biochemical and electrophysiological study. Brain. 1968 Jun;91(2):215–248. doi: 10.1093/brain/91.2.215. [DOI] [PubMed] [Google Scholar]
  22. Osuntokun B. O. Cassava diet, chronic cyanide intoxication and neuropathy in the Nigerian Africans. World Rev Nutr Diet. 1981;36:141–173. doi: 10.1159/000393156. [DOI] [PubMed] [Google Scholar]
  23. Osuntokun B. O. Epidemiology of tropical nutritional neuropathy in Nigerians. Trans R Soc Trop Med Hyg. 1971;65(4):454–479. doi: 10.1016/0035-9203(71)90156-8. [DOI] [PubMed] [Google Scholar]
  24. Osuntokun B. O., Langman M. J., Wilson J., Adeuja A. O., Aladetoyinbo Controlled trial of combinations of hydroxocobalamin-cystine and riboflavine-cystine, in Nigerian ataxic neuropathy. J Neurol Neurosurg Psychiatry. 1974 Jan;37(1):102–104. doi: 10.1136/jnnp.37.1.102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Osuntokun B. O., Langman M. J., Wilson J., Aladetoyinbo A. Controlled trial of hydroxocobalamin and riboflavine in Nigerian ataxic neuropathy. J Neurol Neurosurg Psychiatry. 1970 Oct;33(5):663–666. doi: 10.1136/jnnp.33.5.663. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Osuntokun B. O., Monekosso G. L., Wilson J. Relationship of a degenerative tropical neuropathy to diet: report of a field survey. Br Med J. 1969 Mar 1;1(5643):547–550. doi: 10.1136/bmj.1.5643.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Román G. C., Spencer P. S., Schoenberg B. S. Tropical myeloneuropathies: the hidden endemias. Neurology. 1985 Aug;35(8):1158–1170. doi: 10.1212/wnl.35.8.1158. [DOI] [PubMed] [Google Scholar]
  29. Román G. Tropical myeloneuropathies revisited. Curr Opin Neurol. 1998 Oct;11(5):539–544. doi: 10.1097/00019052-199810000-00017. [DOI] [PubMed] [Google Scholar]
  30. Swenne I., Eriksson U. J., Christoffersson R., Kågedal B., Lundquist P., Nilsson L., Tylleskär T., Rosling H. Cyanide detoxification in rats exposed to acetonitrile and fed a low protein diet. Fundam Appl Toxicol. 1996 Jul;32(1):66–71. doi: 10.1006/faat.1996.0107. [DOI] [PubMed] [Google Scholar]
  31. Tor-Agbidye J., Palmer V. S., Lasarev M. R., Craig A. M., Blythe L. L., Sabri M. I., Spencer P. S. Bioactivation of cyanide to cyanate in sulfur amino acid deficiency: relevance to neurological disease in humans subsisting on cassava. Toxicol Sci. 1999 Aug;50(2):228–235. doi: 10.1093/toxsci/50.2.228. [DOI] [PubMed] [Google Scholar]
  32. Westley J. Mammalian cyanide detoxification with sulphane sulphur. Ciba Found Symp. 1988;140:201–218. doi: 10.1002/9780470513712.ch12. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Neurology, Neurosurgery, and Psychiatry are provided here courtesy of BMJ Publishing Group

RESOURCES