Wandering and disorientation are problems usually suffered by people with dementia. Automatically detecting these mobility patterns is a complex task that has captured the attention of the research community for a long time. Several research projects have been devoted to the analysis of those patterns and their relation with Alzheimer and other cognitive disorders. However, most of them have been focussed on indoor environments. In this paper, we address the problem of detecting mobility patterns associated with wandering and disorientation in outdoor scenarios. To do so, we have analysed the key features of wandering trajectories (specially tailored to this end) and, we have compared them with real trajectories in which wandering was not observed. We have found that, by using some key indicators, significant differences between wandering and normal trajectories can be observed, thus allowing the detection of wandering trajectories in real outdoor scenarios.