Ankle clonus and thiocyanate, linamarin, and inorganic sulphate excretion in school children in communities with Konzo, Mozambique

We examined 397 school children for ankle clonus in five communities in three districts affected by konzo, spastic paraparesis associated with cassava consumption. From a subsample of 131 children, we analysed urine specimens for urinary thiocyanate, linamarin, and inorganic sulphate. The proportion of children with clonus varied between sites, ranging from 4 to 22 per cent. Geometric mean thiocyanate, linamarin, and inorganic sulphate concentrations were 163 and 60 mu mol/l and 4.4 mmol/l, respectively. Children with ankle clonus had higher urinary thiocyanate concentrations. We recommend prevention to reduce cyanide exposure and further monitoring of cyanide exposure and neurological damage in these communities.