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Developmental topographical disorientation (DTD) causes impaired spatial orientation and navigation from early childhood with no evidence of cerebral damage. Using fMRI and a landmark sequencing task, we investigated the hypothesis that Dr Wai's abnormal cerebral activation pattern was related to his peculiar behavioral profile. Although Dr Wai was able to correctly perform landmark sequencing, he showed a lack of activity in regions activated in all control subjects and activity in areas that were not activated in any control subject. These results are discussed in light of cognitive and functional model of navigation, with relevant implications for DTD physiology.

Developmental topographical disorientation (DTD) is a newly discovered cognitive disorder in which individuals experience a lifelong history of getting lost in both novel and familiar surroundings. Recent studies have shown that such a selective orientation defect relies primarily on the inability of the individuals to form cognitive maps, i.e., mental representations of the surrounding that allow individuals to get anywhere from any location in the environment, although other orientation skills are additionally affected. To date, the neural correlates of this developmental condition are unknown. Here, we tested the hypothesis that DTD may be related to ineffective functional connectivity between the hippocampus (HC; known to be critical for cognitive maps) and other brain regions critical for spatial orientation. A group of individuals with DTD and a group of control subjects underwent a resting-state functional magnetic resonance imaging (rsfMRI) scan. In addition, we performed voxel-based morphometry to investigate potential structural differences between individuals with DTD and controls. The results of the rsfMRI study revealed a decreased functional connectivity between the right HC and the prefrontal cortex (PFC) in individuals with DTD. No structural differences were detected between groups. These findings provide evidence that ineffective functional connectivity between HC and PFC may affect the monitoring and processing of spatial information while moving within an environment, resulting in the lifelong selective inability of individuals with DTD to form cognitive maps that are critical for orienting in both familiar and unfamiliar surroundings. © 2014 Wiley Periodicals, Inc.

This article provides a brief overview of the intervention strategies aimed at reducing spatial orientation disorders in elderly people with dementia.Eight experimental studies using spatial cues, assistive technology programs, reality orientation training, errorless learning technique, and backward chaining programs are described. They can be classified into two main approaches: restorative and compensatory, depending on whether they rely or not on residual learning ability, respectively.A review of the efficacy of these intervention strategies is proposed. Results suggest that both compensatory and restorative approaches may be valuable in enhancing correct way-finding behavior, with various degrees of effectiveness. Some issues concerning (a) variability in participants' characteristics and experimental designs and (b) practicality of intervention strategies do not permit to draw a definite conclusion.Future research should be aimed at a direct comparison between these two strategies, and should incorporate an extensive neuropsychological assessment of spatial domain.

We recently developed a new clinical test named card placing test (CPT) which can assess a subject's ability to deal with visuospatial information. The CPT requires a subject to recreate an array of three cards, each of which was randomly placed on eight grids around the subject, before (CPT-A) and after the subject's rotation (CPT-B). With this design, the CPT can assess a subject's ability to represent visuospatial information either egocentrically (CPT-A) or allocentrically (CPT-B). We administered the test on two patients with topographical disorientation; one with egocentric disorientation and another with heading disorientation. The patient with egocentric disorientation demonstrated poor performances on both CPT-A and CPT-B. The patient with heading disorientation, on the other hand, showed good record results for CPT-A but poor ones for CPT-B. An implication is that the patient with egocentric disorientation had disorder in an egocentric reference frame per se, while the patient with heading disorientation could not integrate information on the spatial locations derived from an egocentric reference frame with that on changes of the body directions. We suggest that the CPT is a simple and useful clinical test to evaluate patients with topographical disorientation.

Topographical disorientation, the inability to orient in a well-known environment, is a very incapacitating syndrome. Despite its relatively high frequency after a right cerebral lesion, there is currently no specific neuropsychological test to assess it. We propose a completely new test, with preliminary normative data, assessing the subjects' ability to recall allocentric spatial information from their cognitive map. The subjects are asked to mentally compare distances and directions between landmarks in their familiar environment. This necessitates creating an individual version of the test tailored to every participant's knowledge. This task was proposed to 53 patients with a right lesion and a control group (N = 133). We evaluated performance at comparing distances and directions, and the impact of sociodemographic variables (age, gender, and education). Results show that a right cerebral lesion leads to difficulties in evoking and comparing allocentric spatial information, and more specifically in judging directions. Furthermore, the results show an impact of age, but not gender nor education, on recalling information from a cognitive map. Although there are some intrinsic difficulties (for example in creating patient-specific versions of the test), preliminary normative data indicate that this original test is workable and provides important information in assessing topographical disorientation in clinical practice.

Developmental topographical disorientation (DTD) refers to the lifelong inability to orient in extremely familiar surroundings despite the absence of any acquired brain damage or neurological disorder. Here, we describe the findings of this newly discovered condition, and highlight how this phenomenon provides novel insights into the mechanisms underlying human spatial navigation.

International audience; Spatial navigation, which involves higher cognitive functions, is frequently implemented in daily activities, and is critical to the participation of human beings in mainstream environments. Virtual reality is an expanding tool, which enables on one hand the assessment of the cognitive functions involved in spatial navigation, and on the other the rehabilitation of patients with spatial navigation difficulties. Topographical disorientation is a frequent deficit among patients suffering from neurological diseases. The use of virtual environments enables the information incorporated into the virtual environment to be manipulated empirically. But the impact of manipulations seems differ according to their nature (quantity, occurrence, and characteristics of the stimuli) and the target population. We performed a systematic review of research on virtual spatial navigation covering the period from 2005 to 2015. We focused first on the contribution of virtual spatial navigation for patients with brain injury or schizophrenia, or in the context of ageing and dementia, and then on the impact of visual or auditory stimuli on virtual spatial navigation. On the basis of 6521 abstracts identified in 2 databases (Pubmed and Scopus) with the keywords « navigation » and « virtual », 1103 abstracts were selected by adding the keywords "ageing", "dementia", "brain injury", "stroke", "schizophrenia", "aid", "help", "stimulus" and "cue"; Among these, 63 articles were included in the present qualitative analysis. Unlike pencil-and-paper tests, virtual reality is useful to assess large-scale navigation strategies in patients with brain injury or schizophrenia, or in the context of ageing and dementia. Better knowledge about both the impact of the different aids and the cognitive processes involved is essential for the use of aids in neurorehabilitation.

Topographical disorientation is a clinical syndrome characterized by the inability to find ones way in familiar surroundings and to learn new routes. In neuropsychology it is possible to rehabilitate this disorder with cognitive exercises that provide for the recovery of memory, attention and impaired abilities of executive functions. In general, even if physically navigating in space and reasoning on it can be considered as conceptually linked, cognitive and motor rehabilitation treatments are often provided separately. Contrariwise, introducing an embodied cognition approach, this study aims to investigate the role of motor rehabilitation in the recovery of cognitive spatial ability. We present a single case study of a single male patient admitted with a diagnosis of chronic stroke. In the study he was rehabilitated with Lokomat technology for walking while his cognitive ability in topographical orientation was evaluated before and after the physical training with a standard neuropsychology battery. Moreover, ongoing evaluations in virtual reality spatial tasks were conducted during the rehabilitation period. Data shows an improvement in cognitive performances both in standard tests and virtual ones. The patient, more than a physiotherapy improvement, shows a gradual recovery of its spatial skills. Those data gives insight about the efficacy of embodied approach to rehabilitation by showing how exclusively by rehabilitating the body, with the help of robotic technology, we can expect an improvement in terms of cognitive functioning.

Higher brain dysfunction (HBD) is an umbrella term used for the aftereffects of conditions such as traumatic brain injuries, cerebrovascular disturbances, and encephalitis. Approximately 60 % of persons with HBD lose topographical orientation very easily, which prevents them from walking outdoors without a caregiver. Persons with HBD find existing smartphone navigation applications difficult to master even with extended periods of training; therefore, a smartphone application that can be used by persons with HBD to facilitate independent walking was developed. The new application is simple and easy to use and routes can be specified by caregivers. The system outputs messages via dialogs and voice with vibration, when attention is necessary in cases where the user has arrived at certain sub-goals or has gone off-route. Experiments were conducted with subjects without a disability and HBD subjects to evaluate the effectiveness of the voice and vibration functions. The results showed that the subjects felt that the system was effective and highly usable. However, the average result from the eye mark recorder showed that the viewpoint was concentrated on the smartphone. The result of a second trial conducted with HBD subjects revealed that the average value of time spent observing the device, the number of times the device was observed, and the percentage of time tend to reduce.

Objective Topographical disorientation is a frequent issue in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI). Such impairments are replicated with virtual reality analogs of large-scale spatial navigation tasks. Objective: to evaluate whether visual cues are helpful for virtual spatial navigation and memory in AD and MCI patients. Material/patients and methods Twenty AD patients, 18 MCI patients and 20 age-matched healthy controls (HC) were included. All the participants had to reproduce actively a path including 5 intersections with one landmark at each that they had seen before passively. Three cueing conditions for navigation were proposed: salient landmarks, directional arrows and a map. A path without visual cues served as control condition. Navigation time and number of trajectory mistakes were recorded. After navigation, free recall and recognition of landmarks, landmarks ordering, choice of direction at each intersection and choice of patho outline were assessed. Results With the presence of directional arrows, no significant difference was found between groups concerning the number of trajectory mistakes and navigation time. The number of trajectory mistakes did not differ significantly between AD patients and MCI patients on the path with arrows, the path with salient landmarks and the path with a map. There were significant correlations between the number of trajectory mistakes under the arrow condition and executive tests (TMT and FAB), and between the number of trajectory mistakes under the salient landmark condition and memory tests (FCSRT 16 items and forward verbal span). Discussion – conclusion Visual cueing such as directional arrows and salient landmarks appears helpful for spatial navigation and memory tasks in AD and MCI patients. These visual cueing offers new research avenues for neurorehabilitation, such as the use of augmented reality in real-life settings to support the navigational capabilities of MCI and AD patients.

Buchwald (1878 ) used the term 'mirror writing' to indicate writing in the reverse direction to what is normal in a particular language and in which the individual letters are also reversed. Cases of healthy individuals (i.e., Leonardo da Vinci and Lewis Carroll) as well as brain-damaged patients have been described in the literature. Here, we report the case of PM, a 70-year-old right-handed woman who showed right hemiplegia and mirror writing following a stroke in the left lenticular nucleus and internal capsulae. PM underwent a complete neuropsychological evaluation, which included copying, dictation and spontaneous writing in both hemispaces with both hands. She was also tested for topographical disorientation, visuo-spatial disorders and body schema deficits. We observed isolated mirror writing only when PM wrote with the left hand, without differences between hemispaces. She also showed a left-right disorientation, a body topological map disorder and an egocentric misrepresentation. The presence of mirror writing not confined to one hemispace and the co-presence of executive function disorders, as well as anosognosia, suggests damage to our patient's sub-cortical frontal network. As no previous interpretation fits with PM's symptoms, we hypothesize that mirror writing resulted from damage to her egocentric frame of reference. This hypothesis allows us to interpret the patient's array of disorders, including mirror writing, body topological map disorder, left-right confusion and egocentric representation.

The present field experiment examined how multi-trial visuo-spatial learning and memory performance are impacted by excessive arousal, instigated by a potentially life-threatening event (i.e., a first parachute jump). Throughout a parachute training activity, subjective and neuroendocrine (i.e., cortisol) stress levels were assessed of 61 male military cadets who were randomly assigned to a control (n = 30) or a jump stress condition (n = 31). Post-stress learning and memory capacity was assessed with a 10-trial path-learning task that permitted emergence of learning curves. Pre-activity cortisol concentrations indicated a significant neuroendocrine anticipatory stress response in the stress group. Following parachuting, subjective stress levels and salivary cortisol reactivity differed significantly between groups. Visuo-spatial path-learning performance was impaired significantly after jump stress exposure, relative to the control group. Moreover, examination of the learning curves showed similar learning and memory performance at onset of the trials, with curves bifurcating as the task became more complex. These findings are in accordance with leading theories that acknowledge a moderating effect of task complexity. In sum, the present study extends knowledge concerning anticipatory stress effects, endogenously instigated cortisol reactivity, and the influence of extreme arousal on visuo-spatial path learning.

Defects confined to spatial memory can severely affect a variety of daily life activities, such as remembering the location of objects or navigating the environment, until now the skills involved have been mostly assessed with regard to the visual domain using traditional pencil and paper tests. Our aim was to test the efficacy of a recently developed psychometric instrument (Walking Corsi Test: WalCT) to assess the specific contribution of spatial memory to the complex task of retrieving route knowledge. The WalCT is a 3 × 2.5-m version of the well-known Corsi Block-tapping Test (CBT), in which patients are required to memorize (and replicate) a sequence of body displacements. We assessed the ability of left and right brain-damaged patients, as well as healthy young and senior controls, to perform both the CBT and the WalCT. Results showed differences related to age in the healthy individuals and specific functional dissociations in the brain-damaged patients. The double dissociations found in this study demonstrate the importance of having a task able to detect navigational disorders, because virtual reality tasks are often much too difficult for aged brain-damaged patients to perform.

A 66-year-old, right-handed male, was admitted to our hospital with difficulty in recognizing faces and colors. He had suffered a stroke in the right occipital region three years earlier that had induced left homonymous hemianopsia, but not prosopagnosia. A neurological examination revealed prosopagnosia, color agnosia, constructional apraxia, and topographical disorientation, but not either hemineglect or dressing apraxia. The patient was unable to distinguish faces of familiar persons such as his family and friends, as well as those of unfamiliar persons such as doctors and nurses. Brain MRI demonstrated an old infarction in the right medial occipital lobe and a new hemorrhagic infarction in the left medial occipital lobe, including the fusiform and lingual gyrus. It is unclear whether a purely right medial occipital lesion can be responsible for prosopagnosia, or whether bilateral medial occipital lesions are necessary for this occurrence. The current case indicated that bilateral medial occipital lesions play an important role in inducing porsopagnosia.

The neural network activated during Topographical Memory (TM) tasks in controls overlaps with the earliest affected regions in Alzheimer's disease (AD) but not with those of Semantic Dementia (SD). This suggests that clinical TM tests could be more bespoke to neural dysfunction in early AD and therefore more sensitive and specific. We hypothesized that TM impairment would be characteristic of AD but not of SD making it useful both for early diagnosis and differential diagnosis. TM was assessed in 69 patients (22 mild AD, 15 SD, 32 with mild cognitive impairment (MCI)) and 35 controls, using three tasks: the four mountains test and two novel tests in a virtual town (the Virtual Route Learning Test (VRLT) and the Heading Orientation Test). AD patients were impaired on all TM tasks. The VRLT was the most discriminatory; had the highest correlation with caregiver reports of navigation problems; and correlated strongly with memory, attention/executive function, and to a lesser degree, visuospatial ability. In contrast, SD patients performed well on the TM battery only becoming abnormal with very advanced dementia and performance correlated exclusively with attention/executive function. The VRLT achieved 95% sensitivity and 94% specificity in discriminating AD patients from controls; at the same cut-off, 70% of MCI patients were impaired. When combined with either naming performance or global dementia severity, there was complete separation of AD from SD. The VRLT is ecologically valid, highly sensitive to early AD, and useful in discriminating AD from the non-Alzheimer dementia, SD.

Objective: We used event-related potentials (ERPs) to examine the recognition of familiar faces and scenes in patients with very mild Alzheimer disease (VMAD). Methods: Two types of stimuli, FACEs and SCENEs, and two versions of each type, FAMILIAR and NOVEL, were presented. Three ERPs were compared between VMAD and normal control (NC): (1) P100 to examine basic visual processing, (2) N170 structural encoding, and (3) N250r familiarity. Results: A prominent N170 was elicited by FACEs in P8 and the largest N170 by SCENEs in P3 and P4. Participants had more errors when judging pictures of SCENEs as familiar or not than that of FACEs. In P3 and P4, NC produced larger N170 than VMAD. From N250r in F3, the familiarity effect was absent in VMAD when familiar scenes were provided. This deficit was not seen in processing familiar faces. Conclusions: This study shows that different neural regions are responsible for the early visual processing in the structural encoding of scenes and faces. The pattern of P100 and that of N170 suggest that VMAD patients maintain basic visual processing and structural encoding abilities. A conflict between behavioral and physiological responses may play a role in VMAD patients’ risk of getting lost in familiar environments. Significance: Scene recognition is impaired earlier than face recognition in the course of Alzheimer disease.

Introduction Topographical disorientation is defined as the inability to recognize familiar or unfamiliar environments. While its slowly progressive development is a common feature of neurodegenerative processes like Alzheimer's dementia, acute presentations are less frequent and mostly caused by strategic lesions within the cerebral navigation network. Depending on the lesion site, topographical disorientation can originate from deficits in landmark recognition and utilization for route planning (egocentric navigation deficit), or disturbance of an overarching cognitive map of the spatial environment (allocentric navigation deficit). However, objective measurements of spatial navigation performance over time are largely missing in patients with topographical disorientation. Methods We here report a 55‐year‐old patient with acute topographical disorientation as the single symptom of right‐sided hippocampal hemorrhage and present quantitative gaze‐monitoring head camera‐based analyses of his path‐finding strategy and visual exploration behavior in a real space navigation paradigm. Results The patient exhibited severe allocentric and also egocentric navigation deficits during the acute phase, shown by higher error rates at finding target items. In addition, he showed a more extensive use of search saccades toward, and fixations on, landmarks that could potentially serve as spatial cues. These deficits had been completely compensated for after four months, when the patient performed unremarkably in the real space navigation task, and used even more strongly allocentric path optimization strategies than age‐matched controls. Conclusions This case report highlights the integral function and right‐sided dominance of the hippocampal formation in the cerebral navigation network in humans. It shows that the cognitive map can be restored completely despite a residual hippocampal lesion, which illustrates the enormous plasticity of the cerebral navigation network in humans.

Since there is no cure for glioblastoma multiforme (GBM), the goal of treatment becomes prolonging the survival through cytoreduction while minimising neurological deficits. In this case report, laser interstitial thermal therapy (LITT) was used once the tumour progressed into the isthmus of the cingulate gyrus. One year after temporal lobectomy, disorders of memory, emotion, personality and navigation, likely related to limbic system involvement along with hallucinations and fluctuating cognition occurred as the tumour progressed. After ablation of the posterior cingulum, worsening of topographical disorientation was observed. Per literature review, delirium has been noted in patients with strokes involving the right-sided temporo-parieto-occipital junction, and topographical disorientation has been associated with lesions of the right posterior cingulum. Alternative causes of these deficits were ruled out, leaving structural changes as the primary explanation. This is the first report of the neurological deficits associated with tumour progression and vasogenic oedema in this region.

Topographical disorientation (TD) has not been as extensively studied as other frequent manifestations of Alzheimer's disease (AD). OBJECTIVE: To verify the occurrence of TD and to identify the neuropsychological dysfunctions associated with TD in AD. METHOD: Thirty patients with probable AD, their caregivers and 30 subjects without dementia (controls) were interviewed with a questionnaire and evaluated with tests related to topographical orientation. RESULTS: AD patients, even those with mild dementia, differ from controls in the questionnaire on topographical orientation and in most neuropsychological tests except for tests of spatial working memory, point localization, three dimension and nonsense figure copy. When the performances in the neuropsychological tests of patients with mild or moderate dementia were compared, only landmark recognition and route description were more impaired in moderate dementia. CONCLUSION: TD occurs even in mild dementia of AD, a finding apparently not explained by the impairments of more elementary spatial functions.

We used a recently developed test of spatial memory--the Four Mountains Test--to investigate the core cognitive processes underpinning topographical disorientation in patients with amnestic mild cognitive impairment (a-MCI) and mild Alzheimer's disease (AD). Performance of these clinical groups was compared with age-matched controls, patients with frontotemporal lobar degeneration (FTLD), and patients with subjective memory impairments. We investigated the perception (concurrent match-to-sample) and short-term retention (2-s delayed match-to-sample) of the configuration of topographical features in computer-generated landscapes shown from different viewpoints. Thirty-one patients were tested (7 AD, 6 a-MCI, 7 temporal variant FTLD, 5 frontal variant FTLD, 6 subjective memory impairment) and 25 age- and gender-matched controls. Brain MRI was available for 27 patients; medial temporal lobe atrophy was assessed using a visual rating scale. Patients with a-MCI or mild AD were impaired on topographical short-term memory, but not perception. No other group differences were found on the topographical subtests. Notably, patients with temporal variants of FTLD performed normally, regardless of the laterality of damage. Subtests for the perception and retention of nonspatial aspects of the landscapes (weather conditions, seasonal and daily variations in lighting and color) were poor at differentiating the patient groups. These results indicate a core deficit in representing topographical layout, even for very short durations, within the context of more general long-term memory impairments found in AD, and suggest that this function is particularly sensitive to the earliest stages of the disease.

In the literature it is commonly reported that several spatial abilities decline with normal aging, even though such a decline is not uniform. So far, it is not yet clear which spatial components present a normal age-related decline, which ones are preserved and at what point the deficit is so severe to represent an index of mild cognitive impairment (MCI) or a symptom of potential degenerative progression as in the early-stage Alzheimer's disease (AD). In particular, AD (from early onset) is characterised by impairments in constructive abilities, visuospatial intelligence, spatial short-term memory deficits, and disorders of spatial orientation (topographical disorientation). MCI indicates a condition, generally affecting older individuals, characterized by cognitive deficits including memory and/or non memory impairments and at high risk of progression to dementia. Three MCI subgroups have been distinguished and a very high risk of developing AD is associated to the amnestic MCI subtypes. Further, recent studies have suggested that the allocentric component of spatial memory might be taken as predictor of AD from MCI. Given the frequency of visuospatial deficits in early-stage AD, evaluation of visuospatial processes is a promising approach to find predictive markers of AD. Here we report a review of the literature exploring specific visuospatial components in normal aging, MCI, and AD. In this way we could shed some light on the role of these components in the progression from MCI to AD and pave the way for future studies.

Topographical disorientation is the inability to orient within the environment, usually acquired from lesions to different cerebral regions participating in the attentional, perceptual or memory functions involved during navigation. We present the first case of a patient with topographical disorientation in the absence of any structural lesion and with intact sensory and intellectual function. Experimental tests in both real and virtual environments revealed a selective impairment in forming a mental representation of the environment, namely a cognitive map. Consistent with the patient's behavioural findings, a functional magnetic resonance imaging (fMRI) study showed lack of activation in the hippocampal complex and the retrosplenial cortex while forming a cognitive map of the environment. Although the lack of neural activity results in a negative finding that generally has low interpretative value, in this specific case our findings may provide useful information. First, in a group of healthy control subjects performing the same task, activity within the hippocampal complex and retrosplenial cortex were detected in each individual participant. Second, we found that within the same regions (showing lack of neural activity while forming a cognitive map of the environment) increased neural activity was detected while the patient was performing a different navigation task. This case is the first evidence reported in the literature showing that topographical disorientation may occur as a developmental defect causing a lifelong disorder affecting daily activities.

We describe the case of a young woman with long-lasting topographical disorientation following a haemorrhagic lesion of the right temporo-occipital region involving the hippocampus. She was unable to orient herself in novel environments and to perform learning spatial tasks both in real-world settings and laboratory conditions. Her ability to recall and navigate through known routes as well as to recognize familiar landmarks was preserved. Neuropsychological evaluation revealed a mild long-term memory deficit. A similar neuropsychological and experimental pattern was observed 8 years later (at the time of follow-up) when she showed a persistent topographical disorientation and a slight worsening of verbal and visuo-spatial long-term memory disorders. Her topographical disorientation was characterized by an impairment confined to the anterograde memory domain, a not frequent pattern reported in literature, in the absence of remote topographical memory disorders. The presence of a lesion localized in the right occipito-temporal region and hippocampus combined with the results observed in some experimental tasks could also contribute to the debate of the role of neural correlates involved in topographical spatial knowledge.

Topographical disorientation is marked by difficulty finding one's way in familiar or new environments. The present case study reports findings from a 30-year-old male with encephalomalasia of the left parahippocampal region secondary to brain trauma with subsequent difficulty in learning of new routes. His navigation in premorbidly known (familiar) surroundings was intact. Magnetic resonance images revealed left parahippocampal and bilateral occipital encephalomalasia. Neuropsychological screening showed impairment in structuring a representation of the spatial relationships among landmarks with relatively preserved ability to learn visual and verbal information of these landmarks. Decreased visual perception and inappropriate visual inputs due to cervical dystonia and right homonymous hemianopsia also appear to play a role in his disability. The current knowledge about the neuronal systems involved in visual cognition and topographical orientation also are addressed in this report.

A 69-year-old, right-handed, Japanese male patient presented with pure agraphia with topographical disorientation after hemorrhage in the right parietal lobe. Upon developing cerebral hemorrhage, he was referred to our hospital for close examination of agraphia. There was no paresis or clumsiness in his extremities. His speech was fluent and well-articulated. Neither aphasia nor reading impairments was found, although there was a clear writing impairment with effort and hesitation. His writing of both kanji and kana letters contained additional, absent or deformed strokes or parts. No hemianopia, prosopagnosia, constructional disturbances and dressing apraxia were found. He could recognize familiar buildings or landscapes, but often lost his way around well-known areas. MR images revealed subcortical lesions of precuneus, superior and inferior parietal lobules in the right hemisphere, around the posterior horn of the lateral ventricle. He revealed pure agraphia and topographical disorientation after the right brain haemorrhage, without dementia or personality change. These findings indicate that the right parietal lobe participates in the kinesthetic movements of writing. Some authers have been documented cases of aphasic agraphia or alexia with agraphia caused by right hemisphere damage in dextrals, but pure agraphia caused by the lesion in the right hemisphere is very rare.

We report herein a patient of poststroke dementia (PSD) following left medial occipitoparietal hemorrhage triggered by drainage of an acute traumatic subdural hematoma. The patient, an independent 73-year-old man, became dependent due to dementia. Cognitive dysfunction was characterized by moderately decreased IQ, severe memory disturbances, topographical disorientation, executive dysfunction and loss of self-awareness. Cognitive dysfunction has not advanced for 3 years. Hypo-perfusion in the whole brain, particularly in the left temporal and parietal regions, was visible on 123I-IMP SPECT images. Magnetic resonance imaging demonstrated damage to the left posterior cingulate cortex, cingulate bundle, superior parietal lobule and subcortical region of the occipital lobe. The fornix was spared. Some subcortical small spotted lesions were detected, but periventricular lucency was not prominent. Structures known to be important in memory but spared by the lesion included the thalamus and basal forebrain. Small spotted subcortical lesions were detected in bilateral hippocampi, which are also known to be important in memory, but these were probably silent lesions. This case suggested that dementia is brought on by the lesion of the left posterior cingulate bundle and retrosplenial cortex causing amnesia by disrupting the cingulate-hippocampal connection or the retrosplenial cortex itself, with the lesion of the left occipitoparietal subcortex causing frontal dysfunction by disrupting the dorsal limbic pathway and occipitofrontal fasciculus of the prefrontal circuits.

ferior parietal lobe and the limbic system are impaired, leading to heading disorientation – a disorder in which patients are unable to remember the direction in which to go, although they are still able to recognize familiar buildings and homes [3] . In this study, we report a case of a patient Dear Sir, Since the report by Valenstein et al. [1] , it has been known that a lesion in the dominant retrosplenial region produces amnesia. On the other hand, a lesion in the same location in the nondominant hemisphere produces topographical disorientation [2] . Specifically, connections between the inReceived: November 15, 2006 Accepted: March 17, 2007 Published online: October 11, 2008

Most of our everyday activities take place in familiar environments learned in the past which we need to constantly navigate. Despite our obvious reliance on these remote spatial memories, until quite recently relatively little was known about how they are instantiated in the human brain. Here we will consider developments in the neuropsychological and neuroimaging domains where innovative methodologies and novel analysis techniques are providing new opportunities for exploring the brain dynamics underpinning the retrieval and use of remotely learned spatial information. These advances allow three key questions to be considered anew: What brain areas in humans support the retrieval and use of remotely learned spatial information? Where in the brain are spatial memories stored? Do findings relating to remote spatial memory inform theoretical debates about memory consolidation? In particular, the hippocampus, parahippocampus, retrosplenial and parietal cortices are scrutinized, revealing new insights into their specific contributions to representing spaces and places from the past.

A 72-year-old man with pure topographical disorientation following a focal hemorrhage in the right forceps major of splenium was assessed at 2 weeks and 3 months after the onset. Initially, he could identify familiar buildings and landmarks, but noted topographical disorientation, dysfunction in sense of quarters, and in visuo-spatial function. The improvement of topographical disorientation was attained in 3 months, while the inability of the sense of quarters and manipulating visuo-spatial information remained unchanged. These results suggested the heading disorientation was accompanied with impaired sense of quarters, although disabled sense of quarters continued beyond the recovery of heading disorientation.

Topographical disorientation, the inability to find one's way in large-scale environments, is a relatively common disorder. However, there are relatively few cognitive neuropsychological studies that investigate the nature of topographical cognition. Theoretical progress has been hindered by a number of factors including: terminological confusion; lack of theoretically driven assessment; the use of broad classifications for the nature of underlying impairments; and an ongoing failure to examine topographical skills in real-life settings. As a result, there is currently no well-established or widely accepted theoretical framework encompassing all aspects of this multifaceted area of cognition. In addition, there is a relative paucity of published case studies that include a comprehensive, theoretically based assessment of topographical disorientation, and treatment of the disorder has received virtually no formal investigation (with the exception of Davis & Coltheart, 1999). Thus, the current paper focuses on the development of a broad framework for understanding topographical cognition that integrates a number of recent theories of topographical orientation and mental imagery (Farah, 1984; Kosslyn, 1980; Riddoch & Humphreys, 1989). The aim of the paper is to present a preliminary framework that can be used as a basis for further refinement and development of theoretical proposals, and be employed by clinicians as a starting point for assessment planning.

Topographical disorientation refers to individuals who are unable to find their way around large-scale environments in a normal manner. Childhood topographical disorientation is rarely investigated or reported. Treatment of topographical disorientation is also rare with only one reported treatment study in an adult (Davis & Coltheart, 1999) and no known description of treatment in a child. This paper reports a detailed case analysis of CA, a 6-year-old child with topographical disorientation, and a description of a treatment programme focused on training orientation in the school environment. Assessment of CA revealed mild to moderate visual agnosia in conjunction with severe impairments in general spatial learning and memory, topographical new learning and memory, and a total inability to learn new topographical routes. CA was also unable to use a mental image of his environment, a simple visual plan of his environment or a simple visual map, but was able to follow verbally mediated topographical instructions. The treatment programme focused on improving CA's topographical orientation in the school environment. The programme first involved training in recognition of major school buildings and landmarks and then focused on practical training in route finding along commonly used routes in the school environment. Clear benefits from treatment were evident. The assessment and treatment methods employed provide practical and useful ideas for management of this condition in other children.

We report a 55-year-old right-handed man who presented with topographical disorientation following left retrosplenial hemorrhage. His directional information about familiar places, encoded by previous navigation, was severely impaired, and he could not learn the direction to new places in large-scale spaces beyond the range of visual surveillance. By contrast, he had no difficulties with directional information encoded in a tabletop manner: he could locate major cities or countries on a map, and he also could memorize the spatial relationship of objects in a room. Six months after the ictus, when he had recovered from his directional disorientation, a functional magnetic resonance imaging (fMRI) study of mental navigation demonstrated prominent activation in the retrosplenial area along the right parieto-occipital sulcus and the circumference of the injured area on the left side. The present study, together with previous investigations including clinical case reports, functional neuroimaging, and anatomical and physiological studies on monkeys, suggests that the 'sense of direction' in a large-scale locomotor environment is subserved by the visual area along the parieto-occipital sulcus, and that bilateral deterioration of this function causes directional disorientation.

We report a comprehensive investigation of the anterograde memory functions of two patients with memory impairments (RH and JC). RH had neuroradiological evidence of apparently selective right-sided hippocampal damage and an intact cognitive profile apart from selective memory impairments. JC, had neuroradiological evidence of bilateral hippocampal damage following anoxia due to cardiac arrest. He had anomic and "executive" difficulties in addition to a global amnesia, suggesting atrophy extending beyond hippocampal regions. Their performance is compared with that of a previously reported hippocampal amnesic patient who showed preserved recollection and familiarity for faces in the context of severe verbal and topographical memory impairment [VC; Cipolotti, L., Bird, C., Good, T., Macmanus, D., Rudge, P., & Shallice, T. (2006). Recollection and familiarity in dense hippocampal amnesia: A case study. Neuropsychologia, 44, 489-506.] The patients were administered experimental tests using verbal (words) and two types of non-verbal materials (faces and buildings). Receiver operating characteristic analyses were used to estimate the contribution of recollection and familiarity to recognition performance on the experimental tests. RH had preserved verbal recognition memory. Interestingly, her face recognition memory was also spared, whilst topographical recognition memory was impaired. JC was impaired for all types of verbal and non-verbal materials. In both patients, deficits in recollection were invariably associated with deficits in familiarity. JC's data demonstrate the need for a comprehensive cognitive investigation in patients with apparently selective hippocampal damage following anoxia. The data from RH suggest that the right hippocampus is necessary for recollection and familiarity for topographical materials, whilst the left hippocampus is sufficient to underpin these processes for at least some types of verbal materials. Face recognition memory may be adequately subserved by areas outside of the hippocampus.

A 68-year-old man was admitted to our hospital for rehabilitation of topographical disorientation. Brain magnetic resonance imaging revealed infarction in the right medial side of the occipital lobe. On neuropsychological testing, he scored low for the visual information-processing task; however, his overall cognitive function was retained. He could identify parts of the picture while describing the context picture of the Visual Perception Test for Agnosia but could not explain the contents of the entire picture, representing so-called simultanagnosia. Further, he could morphologically perceive both familiar and new scenes, but could not identify them, representing so-called scene agnosia. We report this case because simultanagnosia associated with a right occipital lobe lesion is rare.

A right posterior cerebral lesion can lead to an inability to orient and can consequently interfere with daily-life autonomy. Despite the wide literature about navigation abilities, it is still difficult to assess topographical disorientation (TD) because of the interindividual specificity of spatial knowledge and the diversity of symptoms. We describe here a set of new tests evaluating spatial cognition in a patient with TD presenting difficulties in navigating inside the hospital and in his hometown more than 3 years after his diffuse ischemic right Sylvian stroke. These tests assess mental imagery (global and specifically spatial imagery), perspective change, and the ability to recall spatial relations in familiar environments. The evaluation revealed difficulties with all the tests (but not in global mental imagery) in this patient when compared with matched controls. Hence, these new tests seem specific and affected by a right hemispheric lesion. The observed deficits can explain, at least partially, the spatial orientation difficulties experienced by this patient in the hospital and familiar environments. In conclusion, these tests could be appropriate tools for the assessment of visuospatial and spatial processes.

This paper describes the rehabilitation process of a patient with severe topographical disorientation. The study demonstrates the sustained effects of a tailor-made, meticulous rehabilitation programme based on the gradual development of compensatory strategies. The patient (RB) had a memory impairment specific to environmental landmarks. He was able to recognise objects in his environment, but was unable to identify any salient object as a landmark and was also unable to derive any directional information from a chosen landmark. As such, his topographical disorientation syndrome was complex in that he had elements of both landmark agnosia and a heading disorientation, as described by Aguirre and D'Esposito (1999). Because of this dual damage to the exocentric framework, the tools and methods used in RB's rehabilitation programme were all based on his intact egocentric frame of reference. Remarkable training effects were found for routes he used frequently. After years of training he could walk these routes without the aid of the written information he had used previously, which can be interpreted as a form of implicit learning. In the 12 years we followed this patient some transfer occurred, as the patient was ultimately able to identify his own landmarks. However, RB remains dependent on other people to construct new routes for him on the basis of these landmarks.

Introduction Mild cognitive impairment (MCI) is considered an early stage of cognitive impairment. Therefore, it is important to identify early cognitive markers of MCI conversion to dementia and topographical disorientation (TD) may help differentiate normal aging from MCI and prodromal Alzheimer's disease (AD). Our aim was to propose a new instrument in elderly healthy subjects and MCI patients of amnestic (aMCI) and non-amnestic (naMCI) type. Method We observed 18 healthy subjects and 18 MCI patients (9 aMCI and 9 naMCI). All participants were submitted to a neuropsychological battery and to a new experimental small-scale spatial navigation test reproducing an ideal city. Results a-MCI patients performed worse in learning a new route, in replacing landmarks in the city and in drawing a map of the city. Na-MCI patients' performance was not different from that observed in healthy subjects, except for a longer time span in Route Forward learning. MCI and healthy samples showed different correlations between experimental subtests and neuropsychological tests. Conclusions Our task seems to be sensitive in pointing out differences in spatial abilities of MCI subtypes, especially with regard to the following subtests: learning a new route, retrieving a landmark's place and building a map of the environment. In comparison with more complex tests, these results allow us to consider the new tool as useful to evaluate spatial navigation in healthy elderly subjects and MCI patients.

I describe the experience of an acute loss of ability to read music and play the piano accurately and expressively following an embolic infarct of the right angular and supramarginal gyri in a setting of chronic migraine. Other parietal deficits included a small visual field defect, visual hallucinations, prosopagnosia, topographical disorientation, disturbance of perception of velocity of moving objects and dyscalculia. Recovery began within a month of the ictus after instituting a regular practice routine. The ability to read and play polyphony recovered before the ability to read homophonic music. A substantial degree of recovery of musical function occurred within 6 months and of the other parietal deficits over a year. Failure to maintain regular practice led to marked though recoverable deterioration. An increased frequency of migraine persisted for some 18 months.

Objective: Survivors of traumatic brain injury (TBI) often have spatial navigation deficits. This study examined such deficits and conducted a detailed analysis of navigational behaviour in a virtual environment.Design: TBI survivors were tested in a computer simulation of the Morris water maze task that required them to find and remember the location of an invisible platform that was always in the same location. A follow-up questionnaire assessed everyday spatial ability.Method: Fourteen survivors of moderate-to-severe TBI were compared to 12 non-injured participants. Results: TBI survivors navigated to a visible platform but could not learn the location of the invisible platform. The difference between TBI survivors and uninjured participants was best indicated by two new dependent variables, path efficacy and spatial scores.Conclusion: This study confirms the capacity of virtual environments to reveal spatial navigation deficits after TBI and establishes the best way to identify such deficits.

Topographical disorientation is usually described in patients who have lost the ability to orient themselves as a consequence of acquired focal brain damage. Here, we describe the case of a 20-year-old woman with a congenital brain malformation who has never been able to orient herself within the environment. We addressed in detail her ability to orient and navigate within the environment by administering a number of tasks in both ecological and experimental surroundings. The results indicate a complete inability to use any kind of strategy useful for orientation.

Background Based on the hypothesis that declarative memory and navigation ability depend on hippocampal integrity, and the fact that declarative memory declines early in Alzheimer's disease (AD), the authors suggest that topographical disorientation (TD) will be an early manifestation of AD. Subjects and methods Patients diagnosed with AD based on DSM-IV criteria, residing at home, were studied in a clinic at a 1000-bed referral medical center. Patient characteristics, disease condition, performance on neuropsychological tests, and navigation function were compared between patients with and without current TD. Information regarding the extent and duration of TD and the level of current navigational function were collected during a clinical interview. Results 112 patients (61 males and 51 females) with mean age of 74 years and disease duration of 37 months completed the study. Among them, 61 currently experienced TD, 20 had required an escort to their home by others, and 28 had TD as an incipient symptom. Those with current TD tended to have a longer disease duration, required an escort to their home by others, and reported a history of repeated change of residence, TD as an incipient symptom, a restricted spatial range within which they felt comfortable (safety range), and disorientation when they were out of familiar territory. In addition, care-givers reported a high level of concern for the safety of those with TD when he or she traveled alone. Conclusion TD in community-dwelling AD patient is common. Caregivers should pay attention to those with longer disease duration and try to avoid changing residence. Developing a brief and valid test for topographical orientation will be helpful for the early detection of TD. Copyright © 2004 John Wiley & Sons, Ltd.

We report the results of tests investigating the recognition of faces, places, and objects in a developmental agnosic, because dissociations of visual recognition in developmental agnosics provide insight into the separable procedures performing recognition and the developmental origins of these procedures. TA is a software engineer in his early 40s with developmental prosopagnosia. He performs normally on tests of low-level vision, and he names objects at the basic level normally. In order to compare his recognition abilities for different classes, we have presented him with a famous landmarks test, a famous faces test, and old/new discriminations involving unfamiliar faces, houses, natural landscapes, cars, horses, guns, sunglasses, and tools. He was impaired on the face recognition tests, but performed normally on the place recognition tests. He also showed severe impairments with horses and cars, borderline impairments with guns and sunglasses, and normal performance with tools. These results indicate that the developmental processes that assemble the procedures used for face recognition and certain types of object recognition are separate from those processes that produce the procedures used for place recognition.

Transient topographical disorientation (TTD) is a short-lasting inability to find one’s way in a familiar environment, while the patient remains conscious and is able to recall what happened. We report the study of 10 patients with episodes of TTD, studied on the days following the last episode. The episodes of TTD could be separated into two types: the patients either reported difficulties in spatial orientation with preserved abilities to recognize landmarks and objects, or the difficulties appeared with the recognition of landmarks. Tests exploring spatial orientation, as well as higher visuoperceptive capacities were altered in most of the patients and brain SPECT showed hypoperfusion of the right hemisphere in all patients, which could also be demonstrated 2 years later in some cases. Altogether, our findings suggest that TTD is frequently associated with a more persistent right hemisphere dysfunction of unknown cause. This chronic alteration could represent either a sequel of the acute episode or a preexisting right hemisphere deficit, which inclined the acute insult to be manifested as TTD.

Objective Many patients suffer from a topographical disorientation after having a stroke. Virtual reality tools allow us to evaluate topographical orientation and spatial navigation of several populations of patients, notably after a stroke. Furthermore, they allow us to add stimuli to the software. Contextual stimuli have been already shown to improve spatial navigation in patients with a stroke. We noticed in a previous study that non-contextual stimuli not linked with the navigational task did not impact the performance of patients with a focal hemispheric lesion. But the impact of non-contextual stimuli with higher perceptual or cognitive salience is not known yet. Objective: to determine if non-contextual stimuli with a high perceptual or cognitive salience decrease the navigation performance of patients who have had a stroke, especially those with dysexecutive disorders. Material/patients and methods Forty patients who have had a stroke and 26 healthy control subjects age- and gender-matched were included in this randomized trial. The participants were first familiarized with the virtual environment, the Virtual Action Planning-Supermarket (VAP-S). Then, the participants had to do a searching task of 7 objects in the VAP-S during 5 consecutive days. The navigational tasks were doing in a randomized order with: sounds providing from living beings, from supermarket's objects, beeping sounds, names of products which were not into the supermarket and without auditory stimuli. The main judgment criterion was a composite score made with the navigation time and the number of collected objects into the VAP-S. Results Patients’ performances were significantly decreased in presence of sounds from living beings, sounds from supermarket's objects, and name of products which were not into the supermarket, especially in patients with dysexecutive disorders. The performances of patients into the VAP-S were correlated with the evaluation of dysexecutive disorders using the GREFEX battery. Discussion – conclusion Non-contextual auditory stimuli with a high perceptual or cognitive salience could be useful in neurorehabilitation paradigms, in order to train patients with dysexecutive disorders to inhibit non-contextual information.

The neurological basis for topographical disorientation has recently shifted from a model of navigation utilizing egocentric techniques alone, to multiple parallel systems of topographical cognition including egocentric and allocentric strategies. We explored if this hypothesis may be applicable to a patient with late-onset blindness. A 72-year-old male with bilateral blindness experienced a sudden inability to navigate after suffering a stroke. Multiple lesions scattered bilaterally throughout the parietal-occipital lobes were found. Deficits in the neural correlates underlying egocentric or allocentric strategies may result in topographical disorientation, even if one appears to be the predominant orientation strategy utilized.