Changes in regional brain grey-matter volume following successful completion of a sensori-motor intervention targeted at healthy and fall-prone older adults

Previous studies have suggested that discrete cross-sensory events could be incorrectly combined in the brain of older adults with a history of falls, possibly undermining motor and balance control. Based on previous findings that multisensory integration is modifiable with practice, even in an ageing population, we designed a serious game, named CityQuest, to train typical, everyday multisensory processes including sensori-motor control, spatial navigation, obstacle avoidance and balance control. Played over several sessions, this game was shown to improve these functions in older adults with and without a history of falls, depending on the specific condition of the game on which they were trained. Here, using voxel-based morphometry analysis of anatomical magnetic resonance imaging (MRI) data, we investigated structural changes in the brain of a smaller group of older adults from those who successfully completed this five-week intervention. A grey-matter (GM) volume increase in the precentral gyrus, and GM volume reduction in the inferior temporal and orbitofrontal gyri, was found for all participants. Changes in GM volume within regions of the cerebellum were differentially associated with fall-prone and healthy older adults. Furthermore, a greater GM volume increase in the precentral gyrus was observed in participants who performed the full CityQuest intervention relative to those required to avoid obstacles only. Our results support previous evidence that multisensory training can affect structural changes in the older brain and have implications for programmes designed for the successful rehabilitation of perceptual and cognitive functions.