Functional brain networks in Developmental Topographical Disorientation

Despite a decade-long study on Developmental Topographical Disorientation, the underlying mechanism behind this neurological condition remains unknown. This lifelong selective inability in orientation, which causes these individuals to get lost even in familiar surroundings, is present in the absence of any other neurological disorder or acquired brain damage. Herein, we report an analysis of the functional brain network of individuals with Developmental Topographical Disorientation ($n = 19$) compared against that of healthy controls ($n = 21$), all of whom underwent resting-state functional magnetic resonance imaging, to identify if and how their underlying functional brain network is altered. While the established resting-state networks (RSNs) are confirmed in both groups, there is, on average, a greater connectivity and connectivity strength, in addition to increased global and local efficiency in the overall functional network of the Developmental Topographical Disorientation group. In particular, there is an enhanced connectivity between some RSNs facilitated through indirect functional paths. We identify a handful of nodes that encode part of these differences. Overall, our findings provide strong evidence that the brain networks of individuals suffering from Developmental Topographical Disorientation are modified by compensatory mechanisms, which might open the door for new diagnostic tools.

Evidence of taxonomy for Developmental Topographical Disorientation: Developmental Landmark Agnosia Case 1

We report Developmental Landmark Agnosia (DLA) in a 6-year-old boy (L.G.) who was referred to us for congenital prosopagnosia (see Pizzamiglio et al., 2017 , in which both testing and rehabilitation of Congenital Prosopagnosia are reported). We investigated his performance using a neuropsychological battery and eye movement recordings. The assessment showed the presence of deficits in recognizing familiar places (along with Congenital Prosopagnosia), but not common objects. Eye movement recordings confirmed his problems in recognizing familiar landmarks and misrecognition of unfamiliar places. L.G. is the first evidence of a DLA, suggesting identification of taxonomy of navigational disorders in Developmental Topographical Disorientation is possible, as in the Acquired Topographical Disorientation.