O motivo é agora melhor conhecido:
http://www.mirror.co.uk/science/scientists-discovered-dementia-patients-lost-9654193
Citando:
"The findings raise the possibility that spatial disorientation could be treated by correcting this imbalance through transcranial stimulation, deep-brain stimulation, or light-based therapy.
Dr Duff concluded: “In the meantime our findings suggest that it may be possible to develop navigation-based cognitive tests for diagnosing Alzheimer’s disease in its initial stages"