Two-point discrimination responses in children with idiopathic toe walking: A feasibility fMRI study

Idiopathic toe walking (ITW) is a diagnosis given to children who walk with an absence or limitation of heel strike in the contact phase of the gait cycle, that are otherwise typically developing. There is emerging evidence that this gait pattern may occur in children who experience tactile sensory processing challenges. This feasibility study aimed to determine if children were able to respond to a sensory stimulus during a fMRI. Children aged between 8-16 years of age, with and without idiopathic toe walking were recruited from general public advertising. Participants were required to perform a two-point discrimination test (task block) and press a button without being tested (control block) during an fMRI using a standard block design. Activation differences were examined in the left frontal pole, left supramarginal gyrus, left parahippocampal gyrus, left paracingulate gyrus and the right superior temporal. Five children were in the typically developing (TD) group and three were in the ITW group. There were between-group activation differences in the decision-making block compared to the control block in the left frontal lobe, parahippocampal gyrus and the right superior temporal gyrus. There was greater variation in activation in the left supramarginal gyrus and the left paracingulate gyrus in the ITW group compared to the typically developing group. Based on this study a future sample size of 15 children per group will be required to detect an adequate effect across chosen regions of interest Conducting fMRI using two-point discrimination testing on this population is feasible. Further research is required with larger population sizes to determine if brain activation patterns during the sensory input decision-making process are different in this population.