Changes in gait while backward counting in demented older adults with frontal lobe dysfunction

Area of Science:

• Neuroscience
• Gerontology
• Biomechanics

Background:

• Gait disorders in dementia are linked to frontal lobe dysfunction.
• Dual-tasking reveals cortical involvement in gait control, influenced by executive function, task difficulty, and motor components.
• Understanding dual-task gait changes in dementia can clarify the frontal lobe's role in motor control.

Purpose of the Study:

• To compare the effects of two mental arithmetic tasks (forward counting and backward counting) of differing difficulty on stride time in older adults with dementia and impaired executive function.
• To analyze both the mean values and coefficient of variation (CV) of stride time under single-task and dual-task conditions.

Main Methods:

• 16 demented older adults with executive dysfunction participated.
• Stride time's mean values and CV were measured using the GAITRite System.
• Participants walked under single-task conditions and while performing forward counting (FC) and backward counting (BC).

Main Results:

• Both dual-task conditions significantly increased stride time's mean values and CV compared to normal walking (p<0.05).
• Backward counting (BC) caused a significantly greater change in stride time's CV compared to forward counting (FC) (p=0.015).
• Fewer numbers were enumerated during BC than FC (p<0.001), indicating greater task difficulty.

Conclusions:

• Backward counting (BC) induced more significant gait parameter changes than forward counting (FC), particularly in gait variability.
• These modifications in gait variability suggest issues with attentional focus during BC.
• The coefficient of variation (CV) of stride time appears to be a valuable metric for assessing gait control in this population.