Journal of Disease and Global Health

Background: Konzo is a neglected neurological disease linked to chronic dietary exposure to cyanogenic cassava. Despite the emergence of interventions, research gaps persist regarding early motor deficits in children at risk. This study addresses the lack of standardized tools and data on subclinical neurodevelopmental impacts in such populations by examining hand dexterity impairments using the Jebsen-Taylor Hand Function Test (JTHFT).

Methods: A case‒control study was conducted involving 90 primary school children aged 7–13 years from cassava-dependent (Etche, n=45) and less-dependent (Choba, n=45) communities in Rivers State, Nigeria. The participants completed seven standardized JTHFT subtests assessing skilled hand function, including writing a sentence, turning over cards, picking up small common objects, simulating feeding with a spoon, stacking checkers, moving large light objects, and moving large heavy objects. The mean task completion times were compared between groups using independent samples t-tests (α = 0.05).

Results: Children in the Etche group exhibited significantly poorer performance in several dexterity tasks compared to controls. Notable differences included slower completion times for page turning (non-dominant: 5.48 ± 1.27 vs. 4.67 ± 1.18 sec, p=0.003), stacking checkers (4.06 ± 0.79 vs. 4.50 ± 0.97 sec, p=0.022), and lifting large heavy objects (non-dominant: 3.32 ± 0.68 vs. 3.92 ± 1.00 sec, p=0.001; dominant: 3.05 ± 0.71 vs. 3.69 ± 0.82 sec, p<0.001). Gender-specific analysis revealed significant impairments among both males and females in the at-risk group.

Conclusion: Children from Konzo-endemic regions demonstrate early, measurable impairments in skilled hand dexterity, particularly in tasks requiring fine motor control and strength. The JTHFT may serve as a sensitive screening tool for subclinical neurotoxicity. These findings support the integration of motor surveillance into public health strategies in cassava-dependent communities.