Allocentric Versus Egocentric Neglect in Stroke Patients: A Pilot Study Investigating the Assessment of Neglect Subtypes and Their Impacts on Functional Outcome Using Eye Tracking.

OBJECTIVE: Few studies have investigated the assessment and functional impact of egocentric and allocentric neglect among stroke patients. This pilot study aimed to determine (1) whether allocentric and egocentric neglect could be dissociated among a sample of stroke patients using eye tracking; (2) the specific patterns of attention associated with each subtype; and (3) the nature of the relationship between neglect subtype and functional outcome. METHOD: Twenty acute stroke patients were administered neuropsychological assessment batteries, a pencil-and-paper Apples Test to measure neglect subtype, and an adaptation of the Apples Test with an eye tracking measure. To test clinical discriminability, twenty age- and education-matched control participants were administered the eye tracking measure of neglect. RESULTS: The eye tracking measure identified a greater number of individuals as having egocentric and/or allocentric neglect than the pencil-and-paper Apples Test. Classification of neglect subtype based on eye tracking performance was a significant predictor of functional outcome beyond that accounted for by the neuropsychological test performance and Apples Test neglect classification. Preliminary evidence suggests that patients with no neglect symptoms had superior functional outcomes compared with patients with neglect. Patients with combined egocentric and allocentric neglect had poorer functional outcomes than those with either subtype. Functional outcomes of patients with either allocentric or egocentric neglect did not differ significantly. The applications of our findings, to improve neglect detection, are discussed. CONCLUSION: Results highlight the potential clinical utility of eye tracking for the assessment and identification of neglect subtype among stroke patients to predict functional outcomes. (JINS, 2019, 25, 479-489).

Spatial and temporal dynamics of visual search tasks distinguish subtypes of unilateral spatial neglect: Comparison of two cases with viewer-centered and stimulus-centered neglect.

We developed a computerised test to evaluate unilateral spatial neglect (USN) using a touchscreen display, and estimated the spatial and temporal patterns of visual search in USN patients. The results between a viewer-centered USN patient and a stimulus-centered USN patient were compared. Two right-brain-damaged patients with USN, a patient without USN, and 16 healthy subjects performed a simple cancellation test, the circle test, a visuomotor search test, and a visual search test. According to the results of the circle test, one USN patient had stimulus-centered neglect and a one had viewer-centered neglect. The spatial and temporal patterns of these two USN patients were compared. The spatial and temporal patterns of cancellation were different in the stimulus-centered USN patient and the viewer-centered USN patient. The viewer-centered USN patient completed the simple cancellation task, but paused when transferring from the right side to the left side of the display. Unexpectedly, this patient did not exhibit rightward attention bias on the visuomotor and visual search tests, but the stimulus-centered USN patient did. The computer-based assessment system provided information on the dynamic visual search strategy of patients with USN. The spatial and temporal pattern of cancellation and visual search were different across the two patients with different subtypes of neglect.

Shining a light on posterior cortical atrophy.

Posterior cortical atrophy (PCA) is a clinicoradiologic syndrome characterized by progressive decline in visual processing skills, relatively intact memory and language in the early stages, and atrophy of posterior brain regions. Misdiagnosis of PCA is common, owing not only to its relative rarity and unusual and variable presentation, but also because patients frequently first seek the opinion of an ophthalmologist, who may note normal eye examinations by their usual tests but may not appreciate cortical brain dysfunction. Seeking to raise awareness of the disease, stimulate research, and promote collaboration, a multidisciplinary group of PCA research clinicians formed an international working party, which had its first face-to-face meeting on July 13, 2012 in Vancouver, Canada, prior to the Alzheimer's Association International Conference.

Phenomenology of the subtypes of delirium: phenomenological differences between hyperactive and hypoactive delirium.

OBJECTIVE: The purpose of this study was to examine the differences in phenomenology between hypoactive and hyperactive subtypes of delirium, and specifically to determine the comparative prevalence of perceptual disturbances (e.g., hallucinations) and delusions in these two subtypes of delirium. METHOD: We conducted an analysis of Memorial Delirium Assessment Scale (MDAS) items in a set of 100 delirium cases evaluated and treated at Memorial Sloan-Kettering Cancer Center (MSKCC) utilizing an MSKCC Institutional Review Board (IRB) approved Clinical Delirium Database. Individual MDAS items, reflecting the phenomenology of delirium, were compared in delirious patients classified as to motoric subtype (hypoactive versus hyperactive based on MDAS item no. 9, psychomotor activity). Particular attention was paid to differences between subtypes as to the prevalence of perceptual disturbances (MDAS item no. 7) and delusions (MDAS item no. 8). RESULTS: Significant differences were found between hyperactive and hypoactive subtypes of delirium for the presence and severity of perceptual disturbances and delusions; with perceptual disturbances (e.g., hallucinations) and delusions being significantly more prevalent in hyperactive than in hypoactive delirium. The prevalence of perceptual disturbances was 50.9% and the prevalence of delusions was 43.4% in patients with hypoactive delirium. In patients with hyperactive delirium, the prevalence of perceptual disturbances was 70.2% and the prevalence of delusions was 78.7%. The prevalence of perceptual disturbances and delusions in both subtypes of delirium was significantly correlated with the presence of moderate-to-severe disturbance of consciousness/arousal (MDAS item no. 1) and attention impairment (MDAS item no. 5), but was not correlated with the presence of moderate-to-severe cognitive impairment (MDAS item nos. 2-4). SIGNIFICANCE OF RESULTS: Contrary to earlier studies, which indicated extremely low prevalence rates of perceptual disturbances (e.g., hallucinations) and delusion in hypoactive delirium, our study demonstrates that the prevalence of perceptual disturbances and delusions in hypoactive delirium is much higher than previously reported (50.9% and 43.4%, respectively), and deserving of clinical attention and intervention.

Environmental orientation and navigation in different types of unilateral neglect.

In this paper, we review several studies that analyze the relationship between lateralized deficits of visuo-spatial processing and deficits in the navigational and topographical domain. In particular, we show that in visuo-spatial or perceptual neglect basic navigational skills are spared. In fact, patients affected by perceptual neglect are able to represent travelled distances and build cognitive maps of real environments despite their difficulty in taking into account left-sided elements. By contrast, although they have no explorative deficits, patients affected by representational neglect show selective impairments in developing, storing and using cognitive maps.

Consecutive versus return motor perseveration during line cancellation task in hemispatial neglect.

BACKGROUND: Patients with neglect often repeatedly cancel the same targets, a form of motor perseveration (MP). There seems to be 2 types of MP, making uninterrupted multiple strokes for each target, consecutive MP (CMP) or return MP (RMP) where patients return to previously canceled targets and remark them. OBJECTIVE: The purpose of this study is to learn whether these 2 forms of MP are dissociable. METHODS: We studied 3 patients, 1 with primarily CMP, another with primarily RMP and a third with mixed CMP and RMP by having them perform the cancellation task with and without background movement. RESULTS: In the patient with primarily RMPs (patient 1), leftward background movement decreased the severity of the neglect and the perseveration. Rightward background movement increased both. In contrast to patient 1, who showed the correspondence between the severity of neglect and perseveration, the patient with both CMP and RMP (patient 2) and the patient with primarily CMPs (patient 3) did not show such correspondence. CONCLUSIONS: The different responses of CMP and RMP to the treatment of neglect suggest that different mechanisms account for these 2 forms of MP. Although RMP might be related to neglect induced aberrant approach behaviors, CMP seems to be related to a disengagement disorder.

Assessment and rehabilitation of acquired visuospatial and proprioceptive deficits associated with visuospatial neglect.

Visuoperceptual disruptions are among the most common, and most debilitating, of the aftereffects following stroke or head injury. Visuospatial neglect in particular, which frequently occurs as a result of insult to the right cerebral hemisphere, has a variety of implications for patient welfare and outcome. And while there exists a great deal of useful information in the area of visual neglect, it is spread out amongst near-countless journal articles, book chapters, and workshop summaries. Thus, it is the purpose of this paper to provide an overview of various topics relating to visuospatial disturbances. Areas covered include theories on sequelae and neuropathology, common direct and indirect complications, rates and types of recovery, past and current trends in assessment and rehabilitation techniques, and thoughts on directions for future research.

[Olfactory disorders]. / Les troubles de l'odorat.

In contrast to what the medical community thought, human olfaction is far more functional and performing than previously believed. Almost fifteen percent of the general population is concerned by an olfactory disorder. The causes of olfactory dysfunction are numerous and in certain cases olfactory alteration precedes neurodegenerative or systemic diseases. Thus, a thorough workup consisting of an otolaryngological examination, olfactory testing and if necessary further exams is emphasized. Since medical knowledge on olfactory dysfunction is only emerging, curative treatments are not always available. In contrast to other neurons, olfactory neurons have the capacity of spontaneous regeneration and a large part of the physician's job is to inform and follow-up patients with olfactory disorders.

Identification of Sensory Processing and Integration Symptom Clusters: A Preliminary Study.

RATIONALE: This study explored subtypes of sensory processing disorder (SPD) by examining the clinical presentations of cluster groups that emerged from scores of children with SPD on the Sensory Processing 3-Dimension (SP-3D) Inventory. METHOD: A nonexperimental design was used involving data extraction from the records of 252 children with SPD. Exploratory cluster analyses were conducted with scores from the SP-3D Inventory which measures sensory overresponsivity (SOR), sensory underresponsivity (SUR), sensory craving (SC), postural disorder, dyspraxia, and sensory discrimination. Scores related to adaptive behavior, social-emotional functioning, and attention among children with different sensory modulation patterns were then examined and compared. RESULTS: Three distinct cluster groups emerged from the data: High SOR only, High SUR with SOR, and High SC with SOR. All groups showed low performance within multiple domains of adaptive behavior. Atypical behaviors associated with social-emotional functioning and attention varied among the groups. IMPLICATIONS: The SP-3D Inventory shows promise as a tool for assisting in identifying patterns of sensory dysfunction and for guiding intervention. Better characterization can guide intervention precision and facilitate homogenous samples for research.

Semiology of neglect: An update.

Hemispatial neglect is a common disabling condition following brain damage to the right hemisphere. Generally, it involves behavioral bias directed ipsilaterally to the damaged hemisphere and loss of spatial awareness for the contralesional side. In this syndrome, several clinical subtypes were identified. The objective of this article is to provide a nosological analysis of the recent data from the literature on the different subtypes of neglect (visual, auditory, somatosensory, motor, egocentric, allocentric and representational neglect), associated ipsilesional and contralesional productive manifestations and their anatomical lesion correlates. These different anatomical-clinical subtypes can be associated or dissociated. They reflect the heterogeneity of this unilateral neglect syndrome that cannot be approached or interpreted in a single manner. We propose that these subtypes result from different underlying deficits: exogenous attentional deficit (visual, auditory neglect); representational deficit (personal neglect, representational neglect, hyperschematia); shift of the egocentric reference frame (egocentric neglect); attentional deficit between objects and within objects (allocentric neglect), endogenous attentional deficit (representational neglect) and transsaccadic working memory or spatial remapping deficit (ipsilesional productive manifestations). Taking into account the different facets of the unilateral neglect syndrome should promote the development of more targeted cognitive rehabilitation protocols.

Anatomy of spatial attention: insights from perfusion imaging and hemispatial neglect in acute stroke.

The site of lesion responsible for left hemispatial neglect after stroke has been intensely debated recently. Some studies provide evidence that right angular lesions are most likely to cause left neglect, whereas others indicate that right superior temporal lesions are most likely to cause neglect. We examine two potential accounts of the conflicting results: (1) neglect could result from cortical dysfunction beyond the structural lesion in some studies; and (2) different forms of neglect with separate neural correlates have been included in different proportions in separate studies. To evaluate these proposals, we studied 50 patients with acute right subcortical infarcts using tests of hemispatial neglect and magnetic resonance diffusion-weighted and perfusion-weighted imaging performed within 48 h of onset of symptoms. Left "allocentric" neglect (errors on the left sides of individual stimuli, regardless of location with respect to the viewer) was most strongly associated with hypoperfusion of right superior temporal gyrus (Fisher's exact test; p < 0.0001), whereas left "egocentric" neglect (errors on the left of the viewer) was most strongly associated with hypoperfusion of the right angular gyrus (p < 0.0001). Patients without cortical hypoperfusion showed no hemispatial neglect. Because the patients did not have cortical infarcts, our data show that neglect can be caused by hypoperfused dysfunctional tissue not detectable by structural magnetic resonance imaging. Moreover, different forms of neglect were associated with different sites of cortical hypoperfusion. Results help explain conflicting results in the literature and contribute to the understanding of spatial attention and representation in the human brain.

Disturbed line bisection is associated with posterior brain lesions.

Neglect patients classically fail to orient and respond to stimuli appearing on their contralesional side. Traditionally, the neglect syndrome has been associated with damage to the right inferior parietal lobule (IPL) and the right temporo-parietal junction (TPJ). Neglect is popularly assessed by two different tasks: line bisection and cancellation. In a previous study (S. Ferber, H.-O. Karnath, How to assess spatial neglect-line bisection or cancellation tasks. J. Clin. Exp. Neuropsychol. 23 (2001) 599-607), we observed that performance on the cancellation task correlates well with the characteristic behavioral disorders used to clinically diagnose spatial neglect, while line bisection was a poor predictor. This might indicate that the disability to correctly bisect lines is a distinct disorder separable from spatial neglect. Here, we assess the anatomy of the patients investigated in that study, and reveal that damage to the temporo-occipital junction correlates with poor performance in the line bisection task. This work extends previous work by Binder et al. (J. Binder, R. Marshall, R. Lazar, J. Benjamin, J.P. Mohr, Distinct syndromes of hemineglect. Arch. Neurol. 49 (1992) 1187-1194) suggesting that line bisection and cancellation identify distinct syndromes. The data suggest that these two tasks dissociate both in terms of behavior and anatomy. This anatomical distinction may help reconcile our recent finding that spatial neglect is associated with damage to the superior temporal cortex and insula, while others have identified the IPL and TPJ. Specifically, we note that our previous anatomical studies did not use the line bisection task to select neglect patients, while many others used this task. We suggest that anatomical studies that combine patients from both of these two distinct groups may result in misleading findings.

Characterisation of unilateral neglect by physiotherapists.

PURPOSE: It is not known how clinicians characterise unilateral neglect (ULN) or whether they consider the different types of ULN during their evaluation and management of patients with this condition. The purpose of this study was to gain insight into physiotherapists' understanding of ULN and to identify the terminology used by clinicians to characterise neglect behaviour. METHOD: Qualitative research design employing focus groups and one-to-one interviews. Thirty-three experienced neurological and novice physiotherapists from one Australian state were asked to discuss how they characterise ULN and to explain what they meant by the terms they used. Data analysis involved preparation of verbatim transcripts followed by coding, data reduction, and identification of major themes. Data management was facilitated using NVivo computer software. FINDINGS: Terms such as sensory neglect, visual neglect, extinction, inattention, and functional neglect were used to characterise neglect behaviour but there was considerable confusion between many of these terms. Motor neglect was an unfamiliar concept to many participants. Functional implications of ULN were considered important. Characterisations of neglect according to the spatial distribution of the behaviour were uncommon. CONCLUSIONS: Despite awareness of many types of neglect, the physiotherapists in this study did not have a clear understanding of how to accurately characterise the different types of ULN. Education to address the issue is required.

[Visuoperceptual processing in Parkinson's disease: from the retina to the frontal cortex]. / Proceso visuoperceptivo en la enfermedad de Parkinson: de la retina a la corteza frontal.

INTRODUCTION: The growing interest in the cognitive impairment shown by patients with Parkinson's disease has led to a wealth of research in this line over recent years. In this paper we review the visuospatial alterations in these patients, which are usually linked to other disorders such as those affecting planning, sequencing, attention or mnemonic processes. DEVELOPMENT: We report the most relevant findings, which suggest that the existence of these visuospatial disorders shown by patients with Parkinson's disease are not always secondary to other frontal-type cognitive impairments, as has been claimed in recent years. Instead, they may be due to disorders in other anterior points of the perceptive process (as a result of dopaminergic deficits in basal-thalamic-cortical circuits). Thus, visuoperceptual disorders are classified according to their location in the brain: from the retina to the lateral geniculate nucleus, the visual cortex and the extrastriate cortex and, finally, the frontal and prefrontal cortex. CONCLUSIONS: We propose this classification of the disorders according to their location to aid in achieving an objective selection of the sample and of the neuropsychological tests used in studies. In this regard, we consider that there should be a higher degree of agreement among researchers when it comes to designing research projects that deal with visuospatial disorders in patients with Parkinson's disease.

Auditory synesthesias.

Synesthesia is experienced when sensory stimulation of one sensory modality (the inducer) elicits an involuntary or automatic sensation in another sensory modality or different aspect of the same sensory modality (the concurrent). Auditory synesthesias (AS) occur when auditory stimuli trigger a variety of concurrents, or when non-auditory sensory stimulations trigger auditory synesthetic perception. The AS are divided into three types: developmental, acquired, and induced. Developmental AS are not a neurologic disorder but a different way of experiencing one's environment. They are involuntary and highly consistent experiences throughout one's life. Acquired AS have been reported in association with neurologic diseases that cause deafferentation of anterior optic pathways, with pathologic lesions affecting the central nervous system (CNS) outside of the optic pathways, as well as non-lesional cases associated with migraine, and epilepsy. It also has been reported with mood disorders as well as a single idiopathic case. Induced AS has been reported in experimental and postsurgical blindfolding, as well as intake of hallucinogenics or psychedelics. In this chapter the three different types of synesthesia, their characteristics, and phenomologic differences, as well as their possible neural mechanisms are discussed.

Categorisation of 'perceptual' and 'premotor' neglect patients across different tasks: is there strong evidence for a dichotomy?

The aim of the presented studies was to investigate whether classifications of neglect patients into perceptual (i.e. identifying a patient as suffering from mainly attentional/space representation deficits) and premotor (judging the main impairment to be related towards actions into contralesional space) categories is consistent across different line bisection assessment techniques that have, in the past, been designed to tease these potentially overlapping aspects of hemispatial neglect apart. Twelve patients with hemispatial neglect and three control groups were tested with the Overhead Task, adapted from Nico [Neuropsychologia 34 (1996) 471] in which patients were asked to bisect lines that were mirror reversed, the Pulley Device Technique, adapted from Bisiach et al. [Neurology 40 (1990) 1278] in which they had to perform a movement opposite to the direction of the transaction mark that bisected the line and the Landmark Test, adapted from Milner et al. [Neuropsychologia 30 (1992) 515] in which they had to manually point to the half of a centrally pre-bisected line that, to them, appeared shorter. The specific question was whether these three tasks would categorise the same set of patients in the same way?Most patients could be classified into either the premotor or perceptual category in each task, but no consistent categorisation emerged across the three techniques. Just 1 out of the 12 patients, was consistently classified across all three tasks. It seemed that despite the fact that all tasks essentially required a line bisection response, the perceptual and motor differences between the tasks were still great enough to result in inconsistent classifications. The Landmark Task classified the majority of patients into the perceptual neglect category, while the Overhead and Pulley Device Techniques tended to identify more patients as suffering from a premotor deficit (albeit not the same set of patients).

A rating scale for psychotic symptoms (RSPS) part I: theoretical principles and subscale 1: perception symptoms (illusions and hallucinations).

The authors present a new rating scale for the psychotic symptoms of schizophrenia and related psychoses. The scale links specific symptoms of psychopathology to dysfunction and overactivity of dopaminergic mechanisms underlying the processes of reward and selective attention. The Rating Scale for Psychotic Symptoms (RSPS) is a 44-item rating instrument with a seven-point severity scale for each item. Psychotic symptoms are classified into three groups: Pathological amplification of mental images (perception symptoms) (subscale 1), Distraction symptoms (including catatonia and passivity experiences) (subscale 2), and Delusions (subscale 3). A dimensional, rather than a categorical, conceptualization of psychosis is assumed. Rating is accomplished through a manual and a semi-structured interview (SSCI-RSPS). In this first of two papers, general issues about the construction of the scale and the derivation of symptom groups are discussed. Dopamine-mediated modification of cortico-striatal synapses is seen as being of critical importance in all three groups of symptoms. In this first paper, we present subscale I (perception symptoms), which includes both amplified perceptual images (illusions) and hallucinations. A total of seven illusions and 11 hallucinations are rated as individual items.

Is face recognition 'special'? Evidence from neuropsychology.

Is face recognition 'special,' in the sense of relying on functionally and anatomically distinct mechanisms from those required for other kinds of pattern recognition? A number of different neuropsychological dissociations involving recognition and learning of faces and nonface objects are reviewed. In addition, studies of the nature of shape representation in normal face and object recognition are reviewed. The evidence from brain-damaged and normal subjects suggests that face recognition is, indeed, 'special,' and provides some clues to the functional differences between face and object recognition.

Dot Enumeration Perceptual Organization Task (DEPOT): evidence for a short-term visual memory deficit in schizophrenia.

The Dot Enumeration Perceptual Organization Task (DEPOT) evaluates the validity of 2 specific competing cognitive models of early input dysfunction in schizophrenic individuals: a primary Stage 1, sensory store, perceptual organization deficit vs. a Stage 2, short-term visual memory (STVM) deficit. DEPOT was also designed to assess the hypothesis that schizophrenic individuals tend to perform poorly on all cognitive tasks. In DEPOT both number and form judgments are made about the same dot patterns. A response delay manipulation assesses the persistence and operation of STVM. The study included 41 psychotic inpatients (8 with acute and 16 with chronic schizophrenia and 7 with bipolar and 10 with nonbipolar affective disorder) and 38 controls (22 college students and 16 hospital personnel). Although the pattern of results was consistent with neither the Stage 1 deficit nor the general deficit hypotheses, a Stage 2, STVM deficit hypothesis could account parsimoniously for the data.