Navigation strategy training using virtual reality in six chronic stroke patients: A novel and explorative approach to the rehabilitation of navigation impairment.

Recent studies have shown that navigation impairment is a common complaint after brain injury. Effective training programmes aiming to improve navigation ability in neurological patients are, however, scarce. The few reported programmes are merely focused on recalling specific routes rather than encouraging brain-damaged patients to use an alternative navigation strategy, applicable to any route. Our aim was therefore to investigate the feasibility of a (virtual reality) navigation training as a tool to instruct chronic stroke patients to adopt an alternative navigation strategy. Navigation ability was systematically assessed before the training. The training approach was then determined based on the individual pattern of navigation deficits of each patient. The use of virtual reality in the navigation strategy training in six middle-aged stroke patients was found to be highly feasible. Furthermore, five patients learned to (partially) apply an alternative navigation strategy in the virtual environment, suggesting that navigation strategies are mouldable rather than static. In the evaluation of their training experiences, the patients judged the training as valuable and proposed some suggestions for further improvement. The notion that the navigation strategy people use can be influenced after a short training procedure is a novel finding and initiates a direction for future studies.

Dissociating spatial and spatiotemporal aspects of navigation ability in chronic stroke patients.

OBJECTIVE: The notion of distinguishable processing mechanisms for spatial and spatiotemporal information has largely been neglected in the context of navigation. Only a recent neuropsychological case study has provided initial evidence for the idea that these elements can be differentiated at a functional level. The aim of the current study was therefore to critically verify this double dissociation by adopting a systematic, large-scale approach. METHOD: Sixty-five chronic stroke patients and 60 matched healthy controls watched a route through a realistic virtual environment. They were assessed on their knowledge of this route in 4 different tasks after the learning phase. Performance on the scene recognition and route continuation tasks was taken as an indication of knowledge of the spatial route aspects. By contrast, spatiotemporal knowledge of the route was assessed in the route order and route progression tasks. RESULTS: Based on single case statistics, 6 patients showed an exceptionally large difference in their performance on the spatial and spatiotemporal tasks. Moreover, 2 patients satisfied formal criteria for a classical dissociation. CONCLUSIONS: Our findings showed that spatial and spatiotemporal performance was closely associated in most patients. Nonetheless, the study also provided partial support for the notion of separate space- and time-based processing mechanisms in the context of navigation. This distinction is of particular relevance to the investigation into the cognitive structure underlying navigation behavior. (PsycINFO Database Record

Severe fatigue and reduced quality of life in children with hereditary motor and sensory neuropathy 1A.

Severe fatigue and low quality of life are reported by a majority of adult patients with hereditary motor and sensory neuropathy 1A. In children with hereditary motor and sensory neuropathy 1A, the prevalence and impact of fatigue have not been studied yet. In this questionnaire survey, 55 Dutch children (response rate 77%) with genetically confirmed hereditary motor and sensory neuropathy 1A participated (mean age 15 years [standard deviation 2.1]). Prevalence of severe fatigue (based on a cut-off score of the Checklist Individual Strength) was 24%, in contrast to 14% in a Dutch school-based population (P < .05). Almost all quality-of-life scores (measured with the Child Health Questionnaire-Child Form 87) were significantly worse than population norms (P < .05). Fatigue severity was associated significantly (P < .01) with all quality-of-life scores (-0.4 < r < -0.7). In conclusion, severe fatigue and diminished quality of life are more frequent among children with hereditary motor and sensory neuropathy 1A compared to healthy peers. The strong association between fatigue severity and quality of life suggests a negative impact of fatigue on quality of life in these children.