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Baguma M, Nzabara F, Maheshe Balemba G, Malembaka EB, Migabo C, Mudumbi G, Bito V, Cliff J, Rigo JM, Chabwine JN. Konzo risk factors, determinants and etiopathogenesis: What is new? A systematic review. Neurotoxicology 2021; 85:54-67. [PMID: 33964344 DOI: 10.1016/j.neuro.2021.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 12/13/2022]
Abstract
Konzo is a toxico-nutritional upper motor neuron disease causing a spastic paraparesis in schoolchildren and childbearing women in some African countries. Almost a century since the first description of konzo, its underlying etiopathogenic mechanisms and causative agent remain unknown. This paper aims at refreshing the current knowledge of konzo determinants and pathogenesis in order to enlighten potential new research and management perspectives. Literature research was performed in PubMed and Web of Science databases according to the PRISMA methodology. Available data show that cassava-derived cyanide poisoning and protein malnutrition constitute two well-documented risk factors of konzo. However, observational studies have failed to demonstrate the causal relationship between konzo and cyanide poisoning. Thiocyanate, the current marker of choice of cyanide exposure, may underestimate the actual level of cyanide poisoning in konzo patients as a larger amount of cyanide is detoxified via other unusual pathways in the context of protein malnutrition characterizing these patients. Furthermore, the appearance of konzo may be the consequence of the interplay of several factors including cyanide metabolites, nutritional deficiencies, psycho-emotional and geo-environmental factors, resulting in pathophysiologic phenomena such as excitotoxicity or oxidative stress, responsible for neuronal damage that takes place at sparse cellular and/or subcellular levels.
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Affiliation(s)
- Marius Baguma
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; Biomedical Research Institute (BIOMED), UHasselt - Hasselt University, Agoralaan, 3590 Diepenbeek, Belgium.
| | - Fabrice Nzabara
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; École Régionale de Santé Publique (ERSP), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Ghislain Maheshe Balemba
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Espoir Bwenge Malembaka
- École Régionale de Santé Publique (ERSP), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Christiane Migabo
- Faculty of Agronomy, Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; Department of Geography and Environmental Studies, College of Social Sciences and Humanities, Jimma University, Jimma, Ethiopia
| | - Germain Mudumbi
- Department of Pediatrics, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Virginie Bito
- Biomedical Research Institute (BIOMED), UHasselt - Hasselt University, Agoralaan, 3590 Diepenbeek, Belgium
| | - Julie Cliff
- Faculty of Medicine, Department of Community Health, Eduardo Mondlane University, Maputo, Mozambique
| | - Jean-Michel Rigo
- Biomedical Research Institute (BIOMED), UHasselt - Hasselt University, Agoralaan, 3590 Diepenbeek, Belgium
| | - Joëlle Nsimire Chabwine
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
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Neuromodulatory activity of trèvo on cyanide-induced neurotoxicity viz neurochemical, antioxidants, cytochrome C oxidase and p53. ADVANCES IN TRADITIONAL MEDICINE 2020. [DOI: 10.1007/s13596-020-00450-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Siddiqi OK, Kapina M, Kumar R, Ngomah Moraes A, Kabwe P, Mazaba ML, Hachaambwa L, Ng'uni NM, Chikoti PC, Morel-Espinosa M, Jarrett JM, Baggett HC, Chizema-Kawesha E. Konzo outbreak in the Western Province of Zambia. Neurology 2020; 94:e1495-e1501. [PMID: 32127386 DOI: 10.1212/wnl.0000000000009017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 10/11/2019] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify the etiology of an outbreak of spastic paraparesis among women and children in the Western Province of Zambia suspected to be konzo. METHODS We conducted an outbreak investigation of individuals from Mongu District, Western Province, Zambia, who previously developed lower extremity weakness. Cases were classified with the World Health Organization definition of konzo. Active case finding was conducted through door-to-door evaluation in affected villages and sensitization at local health clinics. Demographic, medical, and dietary history was used to identify common exposures in all cases. Urine and blood specimens were taken to evaluate for konzo and alternative etiologies. RESULTS We identified 32 cases of konzo exclusively affecting children 6 to 14 years of age and predominantly females >14 years of age. Fourteen of 15 (93%) cases ≥15 years of age were female, 11 (73%) of whom were breastfeeding at the time of symptom onset. Cassava was the most commonly consumed food (median [range] 14 [4-21] times per week), while protein-rich foods were consumed <1 time per week for all cases. Of the 30 patients providing urine specimens, median thiocyanate level was 281 (interquartile range 149-522) μmol/L, and 73% of urine samples had thiocyanate levels >136 μmol/L, the 95th percentile of the US population in 2013 to 2014. CONCLUSION This investigation revealed the first documented cases of konzo in Zambia, occurring in poor communities with diets high in cassava and low in protein, consistent with previous descriptions from neighboring countries.
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Affiliation(s)
- Omar K Siddiqi
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA.
| | - Muzala Kapina
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Ramya Kumar
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Albertina Ngomah Moraes
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Patrick Kabwe
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Mazyanga L Mazaba
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Lottie Hachaambwa
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Namalambo Mwenda Ng'uni
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Patrick C Chikoti
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Maria Morel-Espinosa
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Jeffery M Jarrett
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Henry C Baggett
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
| | - Elizabeth Chizema-Kawesha
- From the Department of Internal Medicine (O.K.S., L.H.), University of Zambia School of Medicine, Lusaka; Global Neurology Program (O.K.S.), Division of Neuroimmunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Ministry of Health (M.K., E.C.-K.); ASPPH/CDC Allan Rosenfield Global Health Fellowship Program (R.K.), Lusaka; Department of Public Health and Research (A.N.M.) and Zambia Field Epidemiology Training Program (P.K.), Ministry of Health; World Health Organization (M.L.M.); Virology Laboratory (M.L.M.) and Department of Physiotherapy (M.N.M.), Children's Hospital, University Teaching Hospital, Lusaka, Zambia; Institute of Human Virology (L.H.), Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore; Zambia Agriculture Research Institute (P.C.C.), Plant Protection and Quarantine Division, Lusaka; and Centers for Disease Control and Prevention (M.M.-E., J.M.J., H.C.B.), Atlanta, GA
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Soil nutrient adequacy for optimal cassava growth, implications on cyanogenic glucoside production: A case of konzo-affected Mtwara region, Tanzania. PLoS One 2019; 14:e0216708. [PMID: 31083702 PMCID: PMC6513093 DOI: 10.1371/journal.pone.0216708] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 04/28/2019] [Indexed: 11/24/2022] Open
Abstract
Soils in areas affected by konzo (a cassava cyanide intoxication paralytic disorder) are predominantly infertile and probably unable to supply cultivated cassava with the nutrients it needs to achieve optimal growth. Soil nutrient supply in these areas could also be influencing cyanogenic glucoside production in cassava, however there is hardly any knowledge on this. An assessment of soil nutrient levels on crop fields in konzo-affected areas was therefore carried out to determine their adequacy for optimal cassava growth. Konzo-affected Mtwara region of Tanzania, was used as a case study. Whether soil nutrient supply influences cyanogenic glucoside production in cassava cultivated in konzo-affected areas and how it could be doing this, was additionally investigated. To investigate this, correlations between total hydrogen cyanide (HCN) levels (a measure of cyanogenic glucoside content) in cassava roots and various soil nutrient levels on crops fields were carried out. This was followed by an investigation of relationships between cases of cassava cyanide intoxication and soil nutrient levels on crop fields from which the consumed toxic cassava roots had been harvested. Cases of cassava cyanide intoxication were used as a proxy for high cyanogenic glucoside levels in cassava roots. Logistic regression analysis was used in the latter investigation. Other important non-nutrient soil chemical characteristics, like pH and soil organic carbon, were also included in all analysis performed. The results revealed that most soil nutrients known to have reducing effects on cassava cyanogenic glucosides, like potassium (mean = 0.09 cmol/kg, SD = 0.05 cmol/kg), magnesium (mean = 0.26 cmol/kg, SD = 0.14 cmol/kg) and zinc (mean = 1.34 mg/kg, SD = 0.26 mg/kg) were deficient on several crop fields. The results also showed that cyanogenic glucosides in cassava roots could be increased with the increased supply of sulphur in soils in bitter cassava varieties (rs = 0.593, p = 0.032), and with the increased supply of P in soils in all cassava varieties (rs = 0.486, p = 0.026). The risk of cassava cyanide intoxication occurring (and thus high cyanogenic glucoside levels in cassava) was found to be likely increased by cultivating cassava on soils with high pH (X2 = 8.124, p = 0.004) and high iron (X2 = 5.740, p = 0.017). The study managed to establish that cassava grows under conditions of severe nutrient stress and that soil nutrient supply influences cyanogenic glucoside production in cassava cultivated in konzo-affected areas of Mtwara region. Despite the multiple soil nutrient deficiencies on crop fields, low soil fertility was however not the only probable cause of increased cyanogenic glucosides in cassava, as high soil nutrient levels were also found to be potential contributors.
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Imakumbili MLE, Semu E, Semoka JMR, Abass A, Mkamilo G. Farmers' perceptions on the causes of cassava root bitterness: A case of konzo-affected Mtwara region, Tanzania. PLoS One 2019; 14:e0215527. [PMID: 30998724 PMCID: PMC6472768 DOI: 10.1371/journal.pone.0215527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 04/03/2019] [Indexed: 11/18/2022] Open
Abstract
In areas where konzo (a cassava cyanide related paralytic disorder) persists, the agronomic factors causing increased cyanogenic glucoside levels in cassava, during periods without water stress, are hardly known. However, through their assessment of cassava root toxicity, using its bitter taste, farmers may have noticed factors unrelated to water stress that additionally influence the cyanogenic glucoside content of cassava cultivated in these areas. Increased cassava root bitterness is often associated with an increase in cyanogenic glucoside levels, making it a good indicator of changes in root cyanogenic glucoside content. Bitter cassava varieties that are preferentially planted by people living in most konzo-affected areas, are an additional known contributor to high cyanogenic glucosides. It is water stress that further increases the inherent toxicity of the planted bitter cassava varieties. Using konzo-affected Mtwara region in Tanzania as a case study, a household survey was carried out to identify the overlooked agronomic factors that additionally influence cyanogenic glucoside levels in cassava cultivated in konzo-affected areas. A total of 120 farmers were interviewed and they mentioned a number of factors unrelated to water stress, as agronomic factors that influenced cassava root bitterness and hence cyanogenic glucoside production in cassava. The mentioned factors included; certain soil characteristics (14.2%), plant age at harvest (7.5%), poor weeding (0.8%), piecemeal harvesting (0.8%), and branch pruning (0.8%). The revealed factors constitute permanent environmental characteristics and crop management practices commonly used by farmers living in konzo-affected Mtwara region in Tanzania. The revealed factors could be contributing to increased cyanogenic glucoside levels in cassava, during periods without water stress in areas where konzo persists.
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Affiliation(s)
- Matema L. E. Imakumbili
- Department of Soils and Geological Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Ernest Semu
- Department of Soils and Geological Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Johnson M. R. Semoka
- Department of Soils and Geological Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Adebayo Abass
- The International Institute of Tropical Agriculture, Dar es Salaam, Tanzania
| | - Geoffrey Mkamilo
- Roots and Tubers Department, Naliendele Agricultural Research Institute, Mtwara, Tanzania
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Tshala-Katumbay DD, Ngombe NN, Okitundu D, David L, Westaway SK, Boivin MJ, Mumba ND, Banea JP. Cyanide and the human brain: perspectives from a model of food (cassava) poisoning. Ann N Y Acad Sci 2016; 1378:50-57. [PMID: 27450775 DOI: 10.1111/nyas.13159] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/29/2016] [Accepted: 06/01/2016] [Indexed: 11/26/2022]
Abstract
Threats by fundamentalist leaders to use chemical weapons have resulted in renewed interest in cyanide toxicity. Relevant insights may be gained from studies on cyanide mass intoxication in populations relying on cyanogenic cassava as the main source of food. In these populations, sublethal concentrations (up to 80 μmol/l) of cyanide in the blood are commonplace and lead to signs of acute toxicity. Long-term toxicity signs include a distinct and irreversible spastic paralysis, known as konzo, and cognition deficits, mainly in sequential processing (visual-spatial analysis) domains. Toxic culprits include cyanide (mitochondrial toxicant), thiocyanate (AMPA-receptor chaotropic cyanide metabolite), cyanate (protein-carbamoylating cyanide metabolite), and 2-iminothiazolidine-4-carboxylic acid (seizure inducer). Factors of susceptibility include younger age, female gender, protein-deficient diet, and, possibly, the gut functional metagenome. The existence of uniquely exposed and neurologically affected populations offers invaluable research opportunities to develop a comprehensive understanding of cyanide toxicity and test or validate point-of-care diagnostic tools and treatment options to be included in preparedness kits in response to cyanide-related threats.
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Affiliation(s)
- Desire D Tshala-Katumbay
- Department of Neurology, School of Medicine, Oregon Health & Science University, Portland, Oregon. .,Department of Neurology, University of Kinshasa, Kinshasa, Congo. .,National Nutrition Program, Ministry of Health, and Kinshasa School of Public Health, Kinshasa, Congo.
| | | | - Daniel Okitundu
- Department of Neurology, University of Kinshasa, Kinshasa, Congo
| | - Larry David
- Department of Biochemistry and Proteomic Share Resource, Oregon Health & Science University, Portland, Oregon
| | - Shawn K Westaway
- Department of Neurology, School of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Michael J Boivin
- Department of Psychiatry and Neurology/Ophthalmology, Michigan State University, East Lansing, Michigan
| | - Ngoyi D Mumba
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Congo.,Institut National de Recherches Biomédicales (INRB), Kinshasa, Congo
| | - Jean-Pierre Banea
- National Nutrition Program, Ministry of Health, and Kinshasa School of Public Health, Kinshasa, Congo
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Kambale KJ, Ali ER, Sadiki NH, Kayembe KP, Mvumbi LG, Yandju DL, Boivin MJ, Boss GR, Stadler DD, Lambert WE, Lasarev MR, Okitundu LA, Mumba Ngoyi D, Banea JP, Tshala-Katumbay DD. Lower sulfurtransferase detoxification rates of cyanide in konzo-A tropical spastic paralysis linked to cassava cyanogenic poisoning. Neurotoxicology 2016; 59:256-262. [PMID: 27246648 DOI: 10.1016/j.neuro.2016.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/26/2016] [Accepted: 05/27/2016] [Indexed: 11/17/2022]
Abstract
Using a matched case-control design, we sought to determine whether the odds of konzo, a distinct spastic paraparesis associated with food (cassava) cyanogenic exposure in the tropics, were associated with lower cyanide detoxification rates (CDR) and malnutrition. Children with konzo (N=122, 5-17 years of age) were age- and sex-matched with presumably healthy controls (N=87) and assessed for motor and cognition performances, cyanogenic exposure, nutritional status, and cyanide detoxification rates (CDR). Cyanogenic exposure was ascertained by thiocyanate (SCN) concentrations in plasma (P-SCN) and urine (U-SCN). Children with a height-for-age z-score (HAZNCHS)<-2 were classified as nutritionally stunted. CDR was measured as time required to convert cyanide to SCN, and expressed as ms/μmol SCN/mg protein or as mmolSCN/ml plasma/min. Mean (SD) U-SCN in children with konzo was 521.9 (353.6) μmol/l and was, significantly higher than 384.6 (223.7) μmol/l in those without konzo. Conditional regression analysis of data for age- and sex- matched case-control pairs showed that konzo was associated with stunting (OR: 5.8; 95% CI: 2.7-12.8; p<0.01; N=83 paired groups) and higher U-SCN (OR: 1.1; 95% CI: 1.02-1.20 per 50-μmol increase in U-SCN; p=0.02; N=47 paired groups). After adjusting for stunting and U-SCN, the odds of developing konzo was reduced by 63% (95% CI: 11-85%, p=0.03; N=41 paired groups) for each 5mmol SCN/(ml plasma/min)-increase in CDR. Linear regression analysis indicated a significant association between BOT-2 or KABC-II scores and both the HAZNCHS z-score and the U-SCN concentration, but not the CDR. Our findings provide evidence in support of interventions to remove cyanogenic compounds from cassava prior to human consumption or, peharps, enhance the detoxification of cyanide in those relying on the cassava as the main source of food.
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Affiliation(s)
- K J Kambale
- Department of Biomedical Sciences, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - E R Ali
- Department of Biology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; Institut National de Recherches Biomédicales (INRB), Congo-Kinshasa, Democratic Republic of the Congo
| | - N H Sadiki
- School of Public Health, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - K P Kayembe
- School of Public Health, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - L G Mvumbi
- Department of Biomedical Sciences, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - D L Yandju
- Department of Biology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - M J Boivin
- Department of Psychiatry and Neurology/Ophthalmology, Michigan State University, East Lansing, MI, USA
| | - G R Boss
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - D D Stadler
- Graduate Programs in Human Nutrition, Oregon Health & Science University, Portland, OR, USA
| | - W E Lambert
- Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, USA
| | - M R Lasarev
- Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, USA; Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA
| | - L A Okitundu
- Department of Neurology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - D Mumba Ngoyi
- Department of Tropical Medicine, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; Institut National de Recherches Biomédicales (INRB), Congo-Kinshasa, Democratic Republic of the Congo
| | - J P Banea
- School of Public Health, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; National Nutrition Program, Ministry of Health, Congo-Kinshasa, Democratic Republic of the Congo
| | - D D Tshala-Katumbay
- Department of Neurology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; Institut National de Recherches Biomédicales (INRB), Congo-Kinshasa, Democratic Republic of the Congo; Department of Neurology, Oregon Health & Science University, Portland, OR, USA.
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8
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Tshala-Katumbay D, Mwanza JC, Rohlman DS, Maestre G, Oriá RB. A global perspective on the influence of environmental exposures on the nervous system. Nature 2015; 527:S187-92. [PMID: 26580326 PMCID: PMC4772865 DOI: 10.1038/nature16034] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Economic transitions in the era of globalization warrant a fresh look at the neurological risks associated with environmental change. These are driven by industrial expansion, transfer and mobility of goods, climate change and population growth. In these contexts, risk of infectious and non-infectious diseases are shared across geographical boundaries. In low- and middle-income countries, the risk of environmentally mediated brain disease is augmented several fold by lack of infrastructure, poor health and safety regulations, and limited measures for environmental protection. Neurological disorders may occur as a result of direct exposure to chemical and/or non-chemical stressors, including but not limited to, ultrafine particulate matters. Individual susceptibilities to exposure-related diseases are modified by genetic, epigenetic and metagenomic factors. The existence of several uniquely exposed populations, including those in the areas surrounding the Niger Delta or north western Amazon oil operations; those working in poorly regulated environments, such as artisanal mining industries; or those, mostly in sub-Saharan Africa, relying on cassava as a staple food, offers invaluable opportunities to advance the current understanding of brain responses to environmental challenges. Increased awareness of the brain disorders that are prevalent in low- and middle-income countries and investments in capacity for further environmental health-related research are positive steps towards improving human health.
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Affiliation(s)
- Desire Tshala-Katumbay
- Department of Neurology, Oregon Health &Science University, Portland, Oregon, 97239, USA.,National Institute of Biomedical Research, 1197 Kinshasa I, Congo.,Department of Neurology, University of Kinshasa, 825 Kinshasa XI, Congo
| | - Jean-Claude Mwanza
- Department of Ophthalmology, University of North Carolina at Chapel Hill, North Carolina 27599, USA
| | - Diane S Rohlman
- Occupational and Environmental Health, The University of Iowa, Iowa 52242, USA.,Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, Oregon, 97239, USA
| | - Gladys Maestre
- G. H. Sergievsky Center, Columbia University Medical Center, New York, New York 10032, USA
| | - Reinaldo B Oriá
- Department of Morphology and Institute of Biomedicine, Faculty of Medicine, Federal University of Ceara, Fortaleza 60020, Brazil
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9
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Reducing neurodevelopmental disorders and disability through research and interventions. Nature 2015; 527:S155-60. [PMID: 26580321 DOI: 10.1038/nature16029] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We define neurodevelopment as the dynamic inter-relationship between genetic, brain, cognitive, emotional and behavioural processes across the developmental lifespan. Significant and persistent disruption to this dynamic process through environmental and genetic risk can lead to neurodevelopmental disorders and disability. Research designed to ameliorate neurodevelopmental disorders in low- and middle-income countries, as well as globally, will benefit enormously from the ongoing advances in understanding their genetic and epigenetic causes, as modified by environment and culture. We provide examples of advances in the prevention and treatment of, and the rehabilitation of those with, neurodevelopment disorders in low- and middle-income countries, along with opportunities for further strategic research initiatives. Our examples are not the only possibilities for strategic research, but they illustrate problems that, when solved, could have a considerable impact in low-resource settings. In each instance, research in low- and middle-income countries led to innovations in identification, surveillance and treatment of a neurodevelopmental disorder. These innovations have also been integrated with genotypic mapping of neurodevelopmental disorders, forming important preventative and rehabilitative interventions with the potential for high impact. These advances will ultimately allow us to understand how epigenetic influences shape neurodevelopmental risk and resilience over time and across populations. Clearly, the most strategic areas of research opportunity involve cross-disciplinary integration at the intersection between the environment, brain or behaviour neurodevelopment, and genetic and epigenetic science. At these junctions a robust integrative cross-disciplinary scientific approach is catalysing the creation of technologies and interventions for old problems. Such approaches will enable us to achieve and sustain the United Nations moral and legal mandate for child health and full development as a basic global human right.
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10
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Gibb H, Devleesschauwer B, Bolger PM, Wu F, Ezendam J, Cliff J, Zeilmaker M, Verger P, Pitt J, Baines J, Adegoke G, Afshari R, Liu Y, Bokkers B, van Loveren H, Mengelers M, Brandon E, Havelaar AH, Bellinger D. World Health Organization estimates of the global and regional disease burden of four foodborne chemical toxins, 2010: a data synthesis. F1000Res 2015; 4:1393. [PMID: 26918123 PMCID: PMC4755404 DOI: 10.12688/f1000research.7340.1] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/19/2015] [Indexed: 01/07/2023] Open
Abstract
Background Chemical exposures have been associated with a variety of health effects; however, little is known about the global disease burden from foodborne chemicals. Food can be a major pathway for the general population's exposure to chemicals, and for some chemicals, it accounts for almost 100% of exposure. Methods and Findings Groups of foodborne chemicals, both natural and anthropogenic, were evaluated for their ability to contribute to the burden of disease. The results of the analyses on four chemicals are presented here - cyanide in cassava, peanut allergen, aflatoxin, and dioxin. Systematic reviews of the literature were conducted to develop age- and sex-specific disease incidence and mortality estimates due to these chemicals. From these estimates, the numbers of cases, deaths and disability adjusted life years (DALYs) were calculated. For these four chemicals combined, the total number of illnesses, deaths, and DALYs in 2010 is estimated to be 339,000 (95% uncertainty interval [UI]: 186,000-1,239,000); 20,000 (95% UI: 8,000-52,000); and 1,012,000 (95% UI: 562,000-2,822,000), respectively. Both cyanide in cassava and aflatoxin are associated with diseases with high case-fatality ratios. Virtually all human exposure to these four chemicals is through the food supply. Conclusion Chemicals in the food supply, as evidenced by the results for only four chemicals, can have a significant impact on the global burden of disease. The case-fatality rates for these four chemicals range from low (e.g., peanut allergen) to extremely high (aflatoxin and liver cancer). The effects associated with these four chemicals are neurologic (cyanide in cassava), cancer (aflatoxin), allergic response (peanut allergen), endocrine (dioxin), and reproductive (dioxin).
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Affiliation(s)
- Herman Gibb
- Gibb Epidemiology Consulting LLC, Arlington, VA, USA
| | - Brecht Devleesschauwer
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
- Institute of Health and Society (IRSS), Université catholique de Louvain, Brussels, Belgium
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Emerging Pathogens Institute and Animal Sciences Department, University of Florida, Gainesville, FL, USA
| | - P. Michael Bolger
- Exponent, Center for Chemical Regulation and Food Safety, Washington, DC, USA
| | - Felicia Wu
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, USA
- Department of Agricultural, Food, and Resource Economics, Michigan State University, East Lansing, MI, USA
| | - Janine Ezendam
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Julie Cliff
- Faculdade de Medicina, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Marco Zeilmaker
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Philippe Verger
- Department of Food Safety and Zoonoses, World Health Organization, Geneva, Switzerland
| | - John Pitt
- CSIRO Food and Nutrition Flagship, North Ryde, Australia
| | - Janis Baines
- Food Data Analysis Section, Food Standards Australia New Zealand, Canberra, Australia
| | - Gabriel Adegoke
- Department of Food Technology, University of Ibadan, Ibadan, Nigeria
| | - Reza Afshari
- Environmental Health Services, British Columbia Centre for Disease Control, Vancouver, BC, Canada
| | - Yan Liu
- INTERTEK, Oak Brook, IL, USA
| | - Bas Bokkers
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Henk van Loveren
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Marcel Mengelers
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Esther Brandon
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Arie H. Havelaar
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
- Emerging Pathogens Institute and Animal Sciences Department, University of Florida, Gainesville, FL, USA
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, Netherlands
| | - David Bellinger
- Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
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11
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Oluwole OSA. Cyclical konzo epidemics and climate variability. Ann Neurol 2015; 77:371-80. [PMID: 25523348 DOI: 10.1002/ana.24334] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 11/30/2014] [Accepted: 12/07/2014] [Indexed: 11/05/2022]
Abstract
Konzo epidemics have occurred during droughts in the Democratic Republic of Congo (DR Congo) for >70 years, but also in Mozambique, Tanzania, and the Central African Republic. The illness is attributed to exposure to cyanide from cassava foods, on which the population depends almost exclusively during droughts. Production of cassava, a drought-resistant crop, has been shown to correlate with cyclical changes in precipitation in konzo-affected countries. Here we review the epidemiology of konzo as well as models of its pathogenesis. A spectral analysis of precipitation and konzo is performed to determine whether konzo epidemics are cyclical and whether there is spectral coherence. Time series of environmental temperature, precipitation, and konzo show cyclical changes. Periodicities of dominant frequencies in the spectra of precipitation and konzo range from 3 to 6 years in DR Congo. There is coherence of the spectra of precipitation and konzo. The magnitude squared coherence of 0.9 indicates a strong relationship between variability of climate and konzo epidemics. Thus, it appears that low precipitation phases of climate variability reduce the yield of food crops except cassava, upon which the population depends for supply of calories during droughts. Presence of very high concentrations of thiocyanate (SCN(-) ), the major metabolite of cyanide, in the bodily fluids of konzo subjects is a consequence of dietary exposure to cyanide, which follows intake of poorly processed cassava roots. Because cyanogens and minor metabolites of cyanide have not induced konzo-like illnesses, SCN(-) remains the most likely neurotoxicant of konzo. Public health control of konzo will require food and water programs during droughts. [Correction added on 26 February 2015, after first online publication: abstract reformatted per journal style]
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12
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Bumoko GMM, Sadiki NH, Rwatambuga A, Kayembe KP, Okitundu DL, Mumba Ngoyi D, Muyembe JJT, Banea JP, Boivin MJ, Tshala-Katumbay D. Lower serum levels of selenium, copper, and zinc are related to neuromotor impairments in children with konzo. J Neurol Sci 2015; 349:149-53. [PMID: 25592410 DOI: 10.1016/j.jns.2015.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/31/2014] [Accepted: 01/02/2015] [Indexed: 11/16/2022]
Abstract
We assessed the relationship between key trace elements and neurocognitive and motor impairments observed in konzo, a motor neuron disease associated with cassava cyanogenic exposure in nutritionally challenged African children. Serum concentrations of iron, copper, zinc, selenium, and neurotoxic lead, mercury, manganese, cadmium, and cobalt were measured in 123 konzo children (mean age 8.53 years) and 87 non-konzo children (mean age 9.07 years) using inductively coupled plasma mass spectrometry (ICPMS). Concentrations of trace elements were compared and related to performance scores on the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) for cognition and Bruininks-Oseretsky Test, 2nd edition (BOT-2) for motor proficiency. Children with konzo had low levels of selenium, copper, and zinc relative to controls. Selenium concentration significantly correlated with serum 8,12-iso-iPF2α-VI isoprostane (Spearman r=0.75, p<0.01) and BOT-2 scores (r=0.31, p=0.00) in children with konzo. Elemental deficiency was not associated with poor cognition. Mean (SD) urinary level of thiocyanate was 388.03 (221.75) μmol/l in non-konzo compared to 518.59 (354.19) μmol/l in konzo children (p<0.01). Motor deficits associated with konzo may possibly be driven by the combined effects of cyanide toxicity and Se deficiency on prooxidant mechanisms. Strategies to prevent konzo may include dietary supplementation with trace elements, preferentially, those with antioxidant and cyanide-scavenging properties.
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Affiliation(s)
- G M-M Bumoko
- Department of Neurology, University of Kinshasa, Democratic Republic Of Congo
| | - N H Sadiki
- School of Public Health, University of Kinshasa, Democratic Republic Of Congo
| | - A Rwatambuga
- Oregon Institute of Occupational Health Sciences and Department of Neurology, Oregon Health & Science University, Portland, OR, USA
| | - K P Kayembe
- School of Public Health, University of Kinshasa, Democratic Republic Of Congo
| | - D L Okitundu
- Department of Neurology, University of Kinshasa, Democratic Republic Of Congo
| | - D Mumba Ngoyi
- Department of Tropical Medicine, University of Kinshasa, Democratic Republic Of Congo; Institut National de Recherches Biomedicales, Democratic Republic Of Congo
| | - J-J T Muyembe
- Department of Tropical Medicine, University of Kinshasa, Democratic Republic Of Congo; Institut National de Recherches Biomedicales, Democratic Republic Of Congo
| | - J-P Banea
- Department of Nutrition, School of Public Health & National Nutrition Program, Ministry of Health, Democratic Republic Of Congo
| | - M J Boivin
- Department of Psychiatry and Neurology/Ophthalmology, Michigan State University, East Lansing, MI, USA
| | - D Tshala-Katumbay
- Department of Neurology, University of Kinshasa, Democratic Republic Of Congo; Institut National de Recherches Biomedicales, Democratic Republic Of Congo; Oregon Institute of Occupational Health Sciences and Department of Neurology, Oregon Health & Science University, Portland, OR, USA.
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13
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Bumoko GM, Sombo MT, Okitundu LD, Mumba DN, Kazadi KT, Tamfum-Muyembe JJ, Lasarev MR, Boivin MJ, Banea JP, Tshala-Katumbay DD. Determinants of cognitive performance in children relying on cyanogenic cassava as staple food. Metab Brain Dis 2014; 29:359-66. [PMID: 24481810 PMCID: PMC4024334 DOI: 10.1007/s11011-014-9492-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
While risk factors for konzo are known, determinants of cognitive impairment in konzo-affected children remain unknown. We anchored cognitive performance (KABC-II scores) to serum levels of free-thyroxine (free-T4), thyroid-stimulating hormone (TSH), albumin, and motor proficiency (BOT-2 scores) in 40 children including 21 with konzo (median age: 9 years) and 19 without konzo (median age: 8 years). A multiple regression model was used to determine variables associated with changes in KABC-II scores. Age (β: -0.818, 95% CI: -1.48, -0.152) (p = 0.018), gender (β: -5.72; 95% CI: -9.87, -1.57 for females) (p = 0.009), BOT-2 score (β: 0.390; 95% CI: 0.113, 0.667) (p = 0.008), and free-T4 (β: 1.88; 95% CI: 0.009, 3.74) (p = 0.049) explained 61.1 % of variation in KABC-II scores. Subclinical hypothyroidism was not associated with poor cognition. A crude association was found between serum albumin and KABC-II scores (β: 1.26; 95 % CI: 0.136, 2.39) (p = 0.029). On spot urinary thiocyanate reached 688 μmol/l in children without konzo and 1,032 μmol/L in those with konzo. Female gender and low serum albumin are risk factors common to cognitive and proportionally associated motor deficits in children exposed to cassava cyanogens. The two types of deficits may share common mechanisms.
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Affiliation(s)
- G M Bumoko
- Department of Neurology, University of Kinshasa, Kinshasa, Congo
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14
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Cross-species and tissue variations in cyanide detoxification rates in rodents and non-human primates on protein-restricted diet. Food Chem Toxicol 2014; 66:203-9. [PMID: 24500607 DOI: 10.1016/j.fct.2014.01.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 11/21/2022]
Abstract
We sought to elucidate the impact of diet, cyanide or cyanate exposure on mammalian cyanide detoxification capabilities (CDC). Male rats (~8 weeks old) (N=52) on 75% sulfur amino acid (SAA)-deficient diet were treated with NaCN (2.5mg/kg bw) or NaOCN (50mg/kg bw) for 6 weeks. Macaca fascicularis monkeys (~12 years old) (N=12) were exclusively fed cassava for 5 weeks. CDC was assessed in plasma, or spinal cord, or brain. In rats, NaCN induced seizures under SAA-restricted diet whereas NaOCN induced motor deficits. No deficits were observed in non-human primates. Under normal diet, the CDC were up to ~80× faster in the nervous system (14 ms to produce one μmol of thiocyanate from the detoxification of cyanide) relative to plasma. Spinal cord CDC was impaired by NaCN, NaOCN, or SAA deficiency. In M. fascicularis, plasma CDC changed proportionally to total proteins (r=0.43; p<0.001). The plasma CDC was ~2× relative to that of rodents. The nervous system susceptibility to cyanide may result from a "multiple hit" by the toxicity of cyanide or its cyanate metabolite, the influences of dietary deficiencies, and the tissue variations in CDC. Chronic dietary reliance on cassava may cause metabolic derangement including poor CDC.
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Kimani S, Moterroso V, Lasarev M, Kipruto S, Bukachi F, Maitai C, David L, Tshala-Katumbay D. Carbamoylation correlates of cyanate neuropathy and cyanide poisoning: relevance to the biomarkers of cassava cyanogenesis and motor system toxicity. SPRINGERPLUS 2013; 2:647. [PMID: 24349951 PMCID: PMC3862856 DOI: 10.1186/2193-1801-2-647] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 11/25/2013] [Indexed: 12/01/2022]
Abstract
We sought to elucidate the protein carbamoylation patterns associated with cyanate neuropathy relative to cyanide poisoning. We hypothesized that under a diet deficient in sulfur amino acids (SAA), the carbamoylation pattern associated with cyanide poisoning is similar to that of cyanate neuropathy. Male rats (6–8 weeks old) were fed a diet with all amino acids (AAA) or 75%-deficiency in SAA and treated with 2.5 mg/kg/body weight (bw) NaCN, or 50 mg/kg/bw NaOCN, or 1 μl/g/bw saline, for up to 6 weeks. Albumin and spinal cord proteins were analyzed using liquid chromatography mass spectrometry (LC-MS/MS). Only NaOCN induced motor deficits with significant levels of carbamoylation. At Day 14, we found a diet-treatment interaction effect on albumin carbamoylation (p = 0.07). At Day 28, no effect was attributed to diet (p = 0.71). Mean number of NaCN-carbamoylated sites on albumin was 47.4% higher relative to vehicle (95% CI:16.7-86.4%). Only NaOCN carbamoylated spinal cord proteins, prominently, under SAA-restricted diet. Proteins targets included myelin basic and proteolipid proteins, neurofilament light and glial fibrillary acidic proteins, and 2', 3' cyclic-nucleotide 3'-phosphodiesterase. Under SAA deficiency, chronic but not acute cyanide toxicity may share biomarkers and pathogenetic similarities with cyanate neuropathy. Prevention of carbamoylation may protect against the neuropathic effects of cyanate.
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Affiliation(s)
- Samuel Kimani
- Department of Pharmacology and Pharmacognosy, University of Nairobi, Nairobi, 19676 Kenya ; School of Nursing Sciences, University of Nairobi, Nairobi, 19676 Kenya
| | - Victor Moterroso
- Department of Comparative Medicine, Oregon Health & Science University (OHSU), Portland, OR 97239 USA
| | - Mike Lasarev
- Center for Research on Occupational & Environmental Toxicology, OHSU, Portland, OR 97239 USA
| | - Sinei Kipruto
- Department of Pharmacology and Pharmacognosy, University of Nairobi, Nairobi, 19676 Kenya
| | - Fred Bukachi
- Department of Medical Physiology, University of Nairobi, Nairobi, 30197 Kenya
| | - Charles Maitai
- Department of Pharmacology and Pharmacognosy, University of Nairobi, Nairobi, 19676 Kenya
| | - Larry David
- Biochemistry and Molecular Biology & Proteomics Shared Resource, OHSU, Portland, OR 97239 USA
| | - Desire Tshala-Katumbay
- Center for Research on Occupational & Environmental Toxicology, OHSU, Portland, OR 97239 USA ; Department of Neurology, OHSU, Portland, OR 97239 USA ; Center for Research on Occupational and Environmental Toxicology & Department of Neurology, Oregon Health & Science University, 3181 Sam Jackson Park Road, Mail code L606, Portland, OR 97239 USA
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16
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Nzwalo H, Cliff J. Konzo: from poverty, cassava, and cyanogen intake to toxico-nutritional neurological disease. PLoS Negl Trop Dis 2011; 5:e1051. [PMID: 21738800 PMCID: PMC3125150 DOI: 10.1371/journal.pntd.0001051] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Konzo is a distinct neurological entity with selective upper motor neuron damage, characterized by an abrupt onset of an irreversible, non-progressive, and symmetrical spastic para/tetraparesis. Despite its severity, konzo remains a neglected disease. The disease is associated with high dietary cyanogen consumption from insufficiently processed roots of bitter cassava combined with a protein-deficient diet. Epidemics occur when these conditions coincide at times of severe food shortage. Up to 1993, outbreaks in poor rural areas in Africa contributed to more than 3,700 cases of konzo. The number of affected people is underestimated. From unofficial reports, the number of cases was estimated to be at least 100,000 in 2000, in contrast to the 6,788 cases reported up to 2009 from published papers.
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17
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Assessing diet in populations at risk for konzo and neurolathyrism. Food Chem Toxicol 2011; 49:655-61. [DOI: 10.1016/j.fct.2010.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 06/29/2010] [Accepted: 08/05/2010] [Indexed: 11/20/2022]
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Adamolekun B. Neurological disorders associated with cassava diet: a review of putative etiological mechanisms. Metab Brain Dis 2011; 26:79-85. [PMID: 21327546 DOI: 10.1007/s11011-011-9237-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 02/02/2011] [Indexed: 10/18/2022]
Abstract
Tropical ataxic neuropathy (TAN) and epidemic spastic paraparesis (konzo) are two neurological disorders associated with the consumption of cassava (Manihot esculenta) in several African countries. TAN is characterized by sensory polyneuropathy, sensory ataxia, bilateral optic atrophy and bilateral sensori-neural deafness. It occurs in elderly individuals subsisting on a monotonous cassava diet with minimal protein supplementation. Konzo is a syndrome of symmetrical spastic paraparesis with a predilection for children and young women and invariably associated with consumption of inadequately processed bitter cassava roots with minimal protein supplementation. Despite numerous epidemiological, clinical and biochemical studies aimed at elucidating the etiological mechanisms of these disorders, their etiologies remain unknown, and there is no known treatment. The diseases continue to be prevalent in endemic areas, causing significant disability and increased mortality. A fresh appraisal of the putative etiologic mechanisms proposed for these intriguing and enigmatic syndromes is presented in this paper. Evidences against a causal role for cyanide intoxication are discussed, and evidences implicating thiamine deficiency as a unifying etiological mechanism for these neurological syndromes are presented. It is concluded that urgent research is needed to evaluate thiamine status and implement a therapeutic trial of thiamine in these debilitating neurological disorders.
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Affiliation(s)
- Bola Adamolekun
- Department of Neurology, University of Tennessee Health Science Center, 855 Monroe Avenue, Memphis, TN 38163, USA.
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Bradbury JH, Cliff J, Denton IC. Uptake of wetting method in Africa to reduce cyanide poisoning and konzo from cassava. Food Chem Toxicol 2011; 49:539-42. [DOI: 10.1016/j.fct.2010.04.049] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 03/18/2010] [Accepted: 04/24/2010] [Indexed: 11/16/2022]
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Effect of Alpha-Ketoglutarate on Neurobehavioral, Neurochemical and Oxidative Changes Caused by Sub-Chronic Cyanide Poisoning in Rats. Neurochem Res 2010; 36:540-8. [DOI: 10.1007/s11064-010-0376-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2010] [Indexed: 10/18/2022]
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Adamolekun B. Etiology of Konzo, epidemic spastic paraparesis associated with cyanogenic glycosides in cassava: Role of thiamine deficiency? J Neurol Sci 2010; 296:30-3. [DOI: 10.1016/j.jns.2010.06.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 05/25/2010] [Accepted: 06/16/2010] [Indexed: 11/17/2022]
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Chabwine JN, Masheka C, Balol'ebwami Z, Maheshe B, Balegamire S, Rutega B, Wa Lola M, Mutendela K, Bonnet MJ, Shangalume O, Balegamire JM, Nemery B. Appearance of konzo in South-Kivu, a wartorn area in the Democratic Republic of Congo. Food Chem Toxicol 2010; 49:644-9. [PMID: 20691241 DOI: 10.1016/j.fct.2010.07.050] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 06/22/2010] [Accepted: 07/29/2010] [Indexed: 10/19/2022]
Abstract
Konzo is an upper motor neuron disease characterized by sudden-onset and irreversible spastic paraparesis occurring in nutritionally compromised people. It is associated with consumption of insufficiently processed cyanogenic-toxic cassava. Cassava, the main caloric source in the Democratic Republic of Congo, has been safely consumed for decades in the Eastern Province of South-Kivu. However, in the context of long-lasting war and violent conflicts, cases of spastic paraparesis resembling konzo appeared in a populous area (Burhinyi). Two field surveys (2003 and 2005) identified 41 subjects meeting clinical criteria of konzo and suffering from (chronic) malnutrition. Their urinary thiocyanate concentrations (median 129, range 20-688, SD 146 μg/L), and cyanogen levels (median 20 ppm, range 5-300 ppm, SD 73 ppm) in cassava roots from their household stocks were high. The source of cyanogenic-toxicity was unprocessed fresh cassava roots during harvest period, but probably also insufficiently processed roots. This first report of konzo in South-Kivu concludes that occurrence of konzo was triggered by food shortages because of the longstanding state of insecurity. Contributory factors included the introduction of new varieties of (bitter) cassava, but konzo may actually be caused by a combination of factors that are yet to be understood.
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Affiliation(s)
- J N Chabwine
- Faculty of Medicine, Université Catholique de Bukavu, PO Box 02, Cyangugu, Rwanda
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Konzo outbreak among refugees from Central African Republic in Eastern region, Cameroon. Food Chem Toxicol 2010; 49:579-82. [PMID: 20538034 DOI: 10.1016/j.fct.2010.05.081] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 05/07/2010] [Accepted: 05/31/2010] [Indexed: 11/22/2022]
Abstract
Konzo is a spastic paraparesis of sudden onset, linked to the exclusive consumption of insufficiently processed bitter cassava as staple food combined with low protein intake. Around 60,000 refugees from the Central African Republic sought refuge in villages in eastern Cameroon between 2005 and 2007. Médecins Sans Frontières was providing nutritional and medical assistance in the villages affected by displacement. We describe cases of konzo seen at the mobile clinics organized in these villages. Basic information including demographic data, history and clinical presentation was recorded for each konzo patient. All patients were given nutritional supplements, and selected cases were referred for physiotherapy to a rehabilitation center. A total of 469 patients were diagnosed with konzo. The majority (80%) were refugees. Children and women of reproductive age predominated. Most of the patients developed symptoms after 2007 in a seasonal pattern with most of the cases occurring during the dry winter season. Most of the patients complained about walking difficulties and weight loss and had exaggerated lower limb reflexes and muscle wasting on observation. Eastern Cameroon is an area with konzo. More effort needs to be put into preventive and educational measures. In addition, timely balanced food rations have to be provided to refugees.
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Kassa RM, Kasensa NL, Monterroso VH, Kayton RJ, Klimek JE, David LL, Lunganza KR, Kayembe KT, Bentivoglio M, Juliano SL, Tshala-Katumbay DD. On the biomarkers and mechanisms of konzo, a distinct upper motor neuron disease associated with food (cassava) cyanogenic exposure. Food Chem Toxicol 2010; 49:571-8. [PMID: 20538033 DOI: 10.1016/j.fct.2010.05.080] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 05/18/2010] [Accepted: 05/19/2010] [Indexed: 12/29/2022]
Abstract
Konzo is a self-limiting central motor-system disease associated with food dependency on cassava and low dietary intake of sulfur amino acids (SAA). Under conditions of SAA-deficiency, ingested cassava cyanogens yield metabolites that include thiocyanate and cyanate, a protein-carbamoylating agent. We studied the physical and biochemical modifications of rat serum and spinal cord proteins arising from intoxication of young adult rats with 50-200mg/kg linamarin, or 200mg/kg sodium cyanate (NaOCN), or vehicle (saline) and fed either a normal amino acid- or SAA-deficient diet for up to 2 weeks. Animals under SAA-deficient diet and treatment with linamarin or NaOCN developed hind limb tremors or motor weakness, respectively. LC/MS-MS analysis revealed differential albumin carbamoylation in animals treated with NaOCN, vs. linamarin/SAA-deficient diet, or vehicle. 2D-DIGE and MALDI-TOF/MS-MS analysis of the spinal cord proteome showed differential expression of proteins involved in oxidative mechanisms (e.g. peroxiredoxin 6), endocytic vesicular trafficking (e.g. dynamin 1), protein folding (e.g. protein disulfide isomerase), and maintenance of the cytoskeleton integrity (e.g. α-spectrin). Studies are needed to elucidate the role of the aformentioned modifications in the pathogenesis of cassava-associated motor-system disease.
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Affiliation(s)
- Roman M Kassa
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, OR, USA
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Soler-Martín C, Riera J, Seoane A, Cutillas B, Ambrosio S, Boadas-Vaello P, Llorens J. The targets of acetone cyanohydrin neurotoxicity in the rat are not the ones expected in an animal model of konzo. Neurotoxicol Teratol 2009; 32:289-94. [PMID: 19932169 DOI: 10.1016/j.ntt.2009.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 11/12/2009] [Accepted: 11/12/2009] [Indexed: 11/30/2022]
Abstract
Konzo is a neurotoxic motor disease caused by excess consumption of insufficiently processed cassava. Cassava contains the cyanogenic glucoside linamarin, but konzo does not present the known pathological effects of cyanide. We hypothesized that the aglycone of linamarin, acetone cyanohydrin, may be the cause of konzo. This nitrile rapidly decomposes into cyanide and acetone, but the particular exposure and nutrition conditions involved in the emergence of konzo may favor its stabilization and subsequent acute neurotoxicity. A number of preliminary observations were used to design an experiment to test this hypothesis. In the experiment, young female Long-Evans rats were given 10mM acetone cyanohydrin in drinking water for 2 weeks, and then 20mM for 6 weeks. Nutrition deficits associated with konzo were modeled by providing tapioca (cassava starch) as food for the last 3 of these weeks. After this period, rats were fasted for 24h in order to increase endogenous acetone synthesis, and then exposed to 0 (control group) or 50 micromol/kg-h of acetone cyanohydrin for 24h (treated group) through subcutaneous osmotic minipump infusion (n=6/group). Motor activity and gait were evaluated before exposure (pre-test), and 1 and 6 days after exposure. Brains (n=4) were stained for neuronal degeneration by fluoro-jade B. Rats exposed to 50 micromol/kg-h of acetone cyanohydrin showed acute signs of toxicity, but no persistent motor deficits. Two animals showed fluoro-jade staining in discrete thalamic nuclei, including the paraventricular and the ventral reuniens nuclei; one also exhibited labeling of the dorsal endopiriform nucleus. Similar effects were not elicited by equimolar KCN exposure. Therefore, acetone cyanohydrin may cause selective neuronal degeneration in the rat, but the affected areas are not those expected in an animal model of konzo.
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Affiliation(s)
- Carla Soler-Martín
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Spain
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Résurgence de la maladie de konzo dans la région sanitaire no 2 en République centrafricaine. Rev Neurol (Paris) 2009; 165:466-70. [DOI: 10.1016/j.neurol.2008.10.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 09/04/2008] [Accepted: 10/08/2008] [Indexed: 11/18/2022]
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Chapter 18 Toxic disorders of the upper motor neuron system. HANDBOOK OF CLINICAL NEUROLOGY 2007; 82:353-72. [DOI: 10.1016/s0072-9752(07)80021-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Mwanza JC, Tshala-Katumbay D, Tylleskär T. Neuro-ophthalmologic manifestations of konzo. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2005; 19:491-496. [PMID: 21783517 DOI: 10.1016/j.etap.2004.12.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Konzo is a permanent spastic paraparesis of acute onset attributed to the effect of cyanogenic compounds from insufficiently processed bitter cassava in combination with low protein intake. In all studies of konzo, ophthalmologic complaints have been presented but only recently systematic studies of the neuro-ophthalmologic disturbances in konzo have been done. In this review, we see that about half the patients have an optic neuropathy with decreased visual acuity, alterations of the visual fields, atrophy of the temporal part of the retinal nerve fibre layer linked with temporal pallor of the optic disk. About half of the konzo patients also have abnormal visual evoked potentials, with both delayed latency and reduced amplitude. A small number of konzo patients have an ocular motor disturbance leading to a pendular nystagmus. The severity of the neuro-ophthalmologic involvement is not parallel to the severity of the motor disturbance in konzo. This may suggest that two different pathogenic mechanisms are involved.
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Affiliation(s)
- Jean-Claude Mwanza
- Department of Ophthalmology, Kinshasa University Hospital, Kinshasa, Congo
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Enfermedades neurológicas asociadas al consumo de variedades de mandioca con alto contenido en gluconitrilos. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s1575-0922(04)74638-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Mwanza JCK, Tshala-Katumbay D, Kayembe DL, Eeg-Olofsson KE, Tylleskär T. Neuro-ophthalmologic findings in konzo, an upper motor neuron disorder in Africa. Eur J Ophthalmol 2003; 13:383-9. [PMID: 12872796 DOI: 10.1177/112067210301300409] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To investigate the neuro-ophthalmological manifestations in konzo, a non-progressive symmetric spastic para/tetraparesis of acute onset associated with consumption of insufficiently processed bitter cassava roots combined with a low protein intake. METHODS Twenty-one Congolese konzo patients underwent neuro-ophthalmological investigations including visual acuity testing, assessment of light pupillary reflexes, evaluation of ocular motility and deviation, direct ophthalmoscopy, and visual field perimetry. Objective refraction including retinoscopy and keratometry, and slit-lamp biomicroscopy were also done. RESULTS Five patients had visual impairment, and 14 had temporal pallor of the optic disc. Fourteen presented visual field defects, the most frequent being concentric constriction and peripheral defects. Overall, 11 subjects had symptoms qualifying for the diagnosis of optic neuropathy. Two had spontaneous pendular nystagmus in primary position of gaze. Visual field defects and pallor of the optic discs were found in mild, moderate and severe forms of konzo. No correlation was found between the severity of the motor disability of konzo and the extent of visual field loss. CONCLUSIONS Konzo was associated with optic neuropathy and a few patients had nystagmus. Although the etiopathogenesis of this optic neuropathy remains to be elucidated, the symmetry of the involvement suggests a toxic origin. We suggest that cyanide causes the neuro-ophthalmological damage in konzo. However, the optic neuropathy in konzo patients does not resemble the features of the epidemic optic neuropathy in Tanzania, Cuba or Nigeria, Leber's hereditary optic neuropathy, tobacco amblyopia or vitamin B deficiency.
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Affiliation(s)
- J C K Mwanza
- Department of Ophthalmology, Kinshasa University Hospital, Kinshasa.
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Ernesto M, Cardoso AP, Nicala D, Mirione E, Massaza F, Cliff J, Haque MR, Bradbury JH. Persistent konzo and cyanogen toxicity from cassava in northern Mozambique. Acta Trop 2002; 82:357-62. [PMID: 12039675 DOI: 10.1016/s0001-706x(02)00042-6] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We aimed to detect new cases of konzo and monitor cyanogen exposure from cassava flour in communities previously affected by konzo epidemics in Nampula Province, northern Mozambique. Other objectives were to detect subclinical upper motor neuron damage in schoolchildren and test a new kit to measure urinary thiocyanate concentration. In 1999 and 2000, we carried out active and passive case detection for konzo in Memba and Mogincual Districts. In July and October, 1999, we collected cassava flour from 30 houses in three communities and measured cyanogen concentrations with a picrate kit. In October 1999, we examined all schoolchildren in three communities for ankle clonus and measured urinary thiocyanate concentration in thirty schoolchildren in each of five communities with a picrate kit. We found 27 new cases of konzo in Mogincual District. Mean total cyanogen concentrations in cassava flour varied between both seasons and years, but were always high, ranging from 26 to 186 ppm. Very high mean levels at three sites in November 1998 and July 1999 were probably due to low rainfall in the 1997-1998 season. The proportion of schoolchildren with ankle clonus varied from 8 to 17%. The new picrate kit for urinary thiocyanate worked well; mean concentrations in schoolchildren ranged from 225 to 384 micromol x l(-1). Konzo and sub-clinical upper motor neuron damage persist in poor rural communities in northern Mozambique, associated with high cyanogen concentrations in cassava flour and high urinary thiocyanate concentrations in schoolchildren.
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Affiliation(s)
- Mario Ernesto
- Direcção Provincial da Saúde, CP 14, Nampula, Mozambique
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Tshala-Katumbay D, Edebol Eeg-Olofsson K, Kazadi-Kayembe T, Fällmar P, Tylleskär T, Kayembe-Kalula T. Abnormalities of somatosensory evoked potentials in konzo--an upper motor neuron disorder. Clin Neurophysiol 2002; 113:10-5. [PMID: 11801419 DOI: 10.1016/s1388-2457(01)00705-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To determine whether the somatosensory pathways are involved or not in konzo. METHODS In 1998, 21 konzo subjects (15 females and 6 males; mean age 21 years) underwent a SEP study with a two-channel-equipment (Medtronic Keypoint, Denmark) whereas in 2000, 15 subjects (7 females and 8 males; mean age 21 years) participated in a study with a 4-channel-equipment. RESULTS Most subjects (19/21 in 1998 and 12/15 in 2000) showed normal median SEPs. The remainders had no median cortical responses. All 21 subjects in 1998 and 9 out of 15 in 2000 showed abnormalities of tibial SEPs mainly consisting of absence of cortical responses, prolonged cortical latencies, and central sensory delay to the lumbar spine. Most subjects showed normal absolute latencies both at peripheral and spinal levels. The SEP findings did not correlate with the severity, neither the duration of konzo, nor the experience or not of sensory symptoms at the onset of the disease. CONCLUSION Our findings are not specific of konzo. However, they suggest involvement of intracranial somatosensory pathways and point to similarities with other motor neuron diseases.
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Mathangi DC, Namasivayam A. Effect of cassava consumption on open-field behavior and brain neurotransmitters in albino rats. Physiol Behav 2000; 70:89-93. [PMID: 10978482 DOI: 10.1016/s0031-9384(00)00252-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Diet exerts a critical influence on human biology and thus studies on the interrelationship of nutrition and behavior continues to be a major and important focus of research in the natural experimental sciences. Cassava is known to cause metabolic and neurological derangement on long-term consumption as a staple diet in the tropics. In this article we present the effects of cassava consumption on open-field behavior and catecholamine levels in the hypothalamus of albino rats. Cassava consumption for 30 days alters the emotional status of the rats, with changes in the basal neurotransmitter levels in the hypothalamus. The role of the cyanide (liberated from cassava) and protein deficiency (associated with cassava consumption) has been discussed.
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Affiliation(s)
- D C Mathangi
- Department of Physiology, Dr.ALM.Postgraduate Institute of Basic Medical Sciences, University of Madras, Taramani, 600 113, Madras, India
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Mathangi DC, Namasivayam A. Neurochemical and behavioural correlates in cassava-induced neurotoxicity in rats. Neurotox Res 2000; 2:29-35. [PMID: 15545004 DOI: 10.1007/bf03033325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Chronic cyanide intoxication from cassava has been implicated as the cause for a degenerative neuropathy known widely as tropical ataxic neuropathy. An attempt has been made in this study to identify the specific cause for neuropathy caused by cassava using Wistar strain albino rats as the experimental animal model. The results of cassava fed animals were compared with control animals, animals given cyanide, malnourished animals and malnourished animals fed cyanide, to identify the causative factors. This study revealed that though the behavioural pattern in motor coordination of the cassava fed animals was similar to the other groups studied, the neurochemical basis for the observed behavioural pattern was unique for cassava. Hence the neurotoxicity of cassava could be attributed to unmetabolized linamarin, more than its nutritional status and/or cyanide toxicity.
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Affiliation(s)
- D C Mathangi
- Department of Physiology, Dr. ALM Postgraduate Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai 600 113, India
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Zaninovic V. On the etiology of tropical spastic paraparesis and human T-cell lymphotropic virus-I-associated myelopathy. Int J Infect Dis 1999; 3:168-76. [PMID: 10460931 DOI: 10.1016/s1201-9712(99)90041-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The purpose of this review is to present some concepts on the etiology of tropical spastic paraparesis or human T-cell lymphotropic virus-I (HTLV-I)-associated myelopathy (TSP/HAM). The large number of syndromes that have been associated with HTLV-I (60 to date), the existence of TSP/HAM cases associated with other retroviruses (human immunodeficiency virus-2 [HIV-2], HTLV-II), the existence of many TSPs without HTLV-I, and the evidence of clear epidemiologic contradictions in TSP/HAM indicate that the etiopathogenesis of TSP/HAM is not yet clear. Tropical spastic paraparesis/HAM affects patients of all human ethnic groups, but usually in well localized and relatively isolated geographic regions where HTLV-I has been endemic for a long time. Environmental factors and geographic locations appear to be critical factors. Because the neuropathology of TSP/HAM suggests a toxometabolic, rather than a viral cause, it is proposed that an intoxication similar to neurolathyrism could account for some of TSP/HAM cases, mainly in tropical and subtropical countries. If this were the case, HTLV-I could be a cofactor or act as a bystander. it is possible that co-infection with another agent is necessary to produce TSP/HAM and most of the syndromes associated with HTLV-I.
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Affiliation(s)
- V Zaninovic
- Emeritus Professor, Clinical Neurology, School of Medicine, Valle University, Cali, Colombia.
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Banea‐Mayambu J, Nkiabungu B, Tylleskär T, Rosling H. High cassava consumption without cyanide exposure in Kinshasa, in former Zaire. Ecol Food Nutr 1998. [DOI: 10.1080/03670244.1998.9991554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
Nine patients with konzo, a symmetric spastic paraparesis of acute onset that occurs during agricultural crises in cassava-growing areas, were re-examined after 14 years. Konzo outbreaks are associated with eating insufficiently processed bitter cassava and a low intake of essential amino acids. Bitter cassava contains cyanogenic glycosides; processing breaks them down to acetone cyanohydrin and hydrogen cyanide. This long-term follow-up showed that the neurological signs in konzo patients remained constant. Four severely affected patients, however, showed functional improvement. This non-progression clearly distinguishes konzo from myelopathy associated with human T lymphotropic virus type I infection. One child, originally classified as a konzo case, showed signs of cretinism at follow-up.
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Affiliation(s)
- J Cliff
- Faculdade de Medicina, Universidade Eduardo Mondlane, Maputo, Mozambique.
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Tylleskär T, Banea M, Böttiger B, Thorstensson R, Biberfeld G, Rosling H. Konzo, an epidemic spastic paraparesis in Africa, is not associated with antibodies to HTLV-I, HIV, or HIV gag-encoded proteins. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY : OFFICIAL PUBLICATION OF THE INTERNATIONAL RETROVIROLOGY ASSOCIATION 1996; 12:317-8. [PMID: 8673538 DOI: 10.1097/00042560-199607000-00014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Abstract
The introduction of palliative therapies in amyotrophic lateral sclerosis (ALS) will alter the epidemiology of ALS as it is known now. Although incidence rates will remain unchanged in the near future, prevalence rates will likely increase dramatically. Better understanding of the age-specific presentation of motor neuron diseases worldwide will shed light on the vexing questions concerning the variable incidence rates in some countries and apparent incidence gradients in North America and Europe.
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Affiliation(s)
- B R Brooks
- Neurology Service, William S. Middleton Memorial VA Medical Center, Madison, Wisconsin, USA
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Improved cassava-processing can help reduce iodine deficiency disorders in the Central African Republic. Nutr Res 1995. [DOI: 10.1016/0271-5317(95)00046-l] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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