Non-evolutive spastic and symmetrical paraparesis, linked to subacute cyanide poisoning contained in poorly washed bitter cassava. Small outbreaks in Central Africa (RD Congo especially). Protein (and mainly sulphur amino acids) deficiency is a factor because only about 1% of the population consuming poorly washed bitter cassava suffers from the disease.

Acute onset within a few days (< 1 week): general weakness (sometimes visual disturbances) but spasticity of the lower limbs is present at the onset. Typically: tiptoe walking, rigid legs, hyperreflexia / at the level of the lower limbs. Konzo means " fasten legs" in the local language.

Patients also present memory and spatio-visual integration disorders just as the children with protein deficiency who are at risk of disease but do not present  neuromotor disorders.

Prevention: the bitter cassava must stay at least 3 nights in water and be dried for at least 6 days before being consumed.

Anesthetic implications:

paraparesis of lower limb with muscle atrophy: avoid succinylcholine (risk of hyperkalemia ?); no contraindication to regional anesthesia

References : 

-         Boivin MJ, Okitundu D, Makiba-Mabe Bumoko F, Sombo M-T et al. 
Neuropsychological effects of Konzo : a neuromotor disease associated with poorly processed cassava. 
Pediatrics 2013; 131: e 1231-9.

Updated: February 2019