Long-lasting topographical disorientation in new environments

Severe developmental topographical disorientation associated with ADHD and dyscalculia: A case report

We report the clinical case of AB, a right-handed 19-year-old woman who presents severe developmental topographical disorientation, a relatively rare syndrome, leading to difficulties in navigating in familiar (and novel) environments. This symptomatology appears without acquired cerebral damage (MRI described as normal) nor more global cognitive disability (high degree of education achieved). An extensive assessment of spatial cognition with different aspects of underlying cognitive processes is first presented. Second, the patient's preserved cognitive abilities and her major difficulties in calculation, as well as her attention deficit, as seen in a detailed neuropsychological assessment, are reported. For the first time to our knowledge, we show that developmental topographical disorientation can be associated with other developmental cognitive disorders affecting number processing (dyscalculia) and attention (Attention Deficit-Hyperactivity Disorder (ADHD)). We discuss the links between these different cognitive processes in relation to visuo-spatial working memory and magnitude representation, which could represent common denominators for all these syndromes. This case report highlights the importance of thoroughly assessing potentially associated neurocognitive disorders in developmental topographical disorientation. In addition, it highlights the necessity to keep in mind the prevalence of spatial difficulties in the assessment of children and adolescents with other neurodevelopmental syndromes. Finally, this case study raises a new question about the nosology of developmental disorders affecting the visuo-spatial and spatial domains.

Memory for novel and familiar environments relies on the hippocampus: A case study on a patient with a right anteromesial temporal lobectomy

While the hippocampus has been ascribed a prominent role in navigation ability, it is still a subject of debate whether it contributes to learning novel environments only or to remembering familiar environments as well. We attempt to shed light on this issue by reporting on a patient who developed complaints of severe difficulties with navigation after she underwent a right anteromesial temporal lobectomy. A standard neuropsychological assessment revealed only a visuospatial working memory deficit. Clear evidence for problems with novel environments were found on a virtual route learning test. Two real‐world tests were used to investigate her ability to recall familiar environments. The first test was based on the area she grew up in (and still visits regularly) and the second test concerned her current place of residence which she never visited prior to the surgery. While her landmark recognition in general was accurate, she showed notable difficulties with indicating their locations on a map and with giving accurate route descriptions between them for both real‐world environments. This pattern of findings suggests that the hippocampus is not only important for navigation in novel environments, but also for familiar environments learned long ago.

The Perceptual Maze Test Revisited: Evaluating the Difficulty of Automatically Generated Mazes

The Elithorn perceptual maze test is widely used in clinical research and practice. However, there is little evidence of its psychometric properties, and its application is limited by the technical difficulty of developing more mazes. The current research aims to adopt a rigorous approach to evaluate 18 mazes that were automatically generated by a novel R software package. Various item response theory models were employed to examine the difficulty parameters. The findings suggested that the data best fitted the Rasch model. The linear logistic test model revealed meaningful contribution to the sources of maze difficulty. Additionally, the linear logistic test model plus error was considered the most parsimonious model. The Automatic Perceptual Maze Test was moderately correlated with a nonverbal intelligence test. By introducing more mazes to provide adequate information on participants' ability at all levels, the Automatic Perceptual Maze Test promises future clinical and research utility for the study of cognitive performance.

Cognitive and behavioral deficits following bilateral thalamic stroke: a longitudinal study

We describe behavioral and neuropsychological outcome of a patient (N.S.), who showed a bilateral paramedian thalamic ischemic lesion, with particular reference to the longitudinal evolution of topographical disorientation (TD) and confabulations. We report clinical neuropsychological/behavioral data over a 43-month follow-up. The results show early after the stroke a severe amnesic-confabulatory syndrome with dysexecutive deficits, associated with memory disorders both for visuo-spatial and verbal materials and TD both for known and new places. Behavioral disinhibition and anosognosia for cognitive deficits were also observed. All cognitive impairments have been recovered during the long-term follow-up. Bilateral paramedian thalamic infarcts often lead to severe and long-lasting neurological and cognitive impairments. Only a few cases showed good recovery. Our patient represents an interesting and uncommon case of bilateral paramedian thalamic syndrome with a significant neuropsychological recovery.

The transfer from survey (map-like) to route representations into Virtual Reality Mazes: effect of age and cerebral lesion

BACKGROUND

To go from one place to another, we routinely generate internal representations of surrounding spaces, which can include egocentric (body-centred) and allocentric (world-centred) coordinates, combined into route and survey representations.Recent studies have shown how both egocentric and allocentric representations exist in parallel and are joined to support behaviour according to the task.Our study investigated the transfer from survey (map-like) to route representations in healthy and brain-damaged subjects. The aim was two-fold: first, to understand how this ability could change with age in a sample of healthy participants, aged from 40 to 71 years old; second, to investigate how it is affected after a brain lesion in a 8 patients' sample, with reference to specific neuropsychological frames.

METHODS

Participants were first required to perform the paper and pencil version of eight mazes, then to translate the map-like paths into egocentric routes, in order to find the right way into equivalent Virtual Reality (VR) mazes.Patients also underwent a comprehensive neuropsychological evaluation, including a specific investigation of some topographical orientation components.

RESULTS

As regards the healthy sample, we found age-related deterioration in VR task performance. While education level and gender were not found to be related to performance, global cognitive level (Mini Mental State Examination), previous experience with computer and fluidity of navigation into the VR appeared to influence VR task results.Considering the clinical sample, there was a difficulty in performing the VR Maze task; executive functions and visuo-spatial abilities deficits appeared to be more relevant for predicting patients' results.

CONCLUSIONS

Our study suggests the importance of developing tools aimed at investigating the survey to route transfer ability in both healthy elderly and clinical samples, since this skill seems high cognitive demanding and sensitive to cognitive decline.Human-computer interaction issues should be considered in employing new technologies, such as VR environments, with elderly subjects and neurological patients.