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).

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.

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.

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.

Flashbacks and HPPD: A Clinical-oriented Concise Review.

A unique characteristic of LSD, LSD-like and substances with hallucinogenic properties is the recurrence of some or all the hallucinogenic symptoms which had appeared during the intoxication after the immediate effects of the substance had worn off. This recurring syndrome, mainly visual, is not clearly understood. The terms Flashback and Hallucinogen Persisting Perception Disorder (HPPD) have been used interchangeably in the professional literature. We have observed at least two different recurrent syndromes, the first Flashback Type we refer to as HPPD I, a generally short-term, non-distressing, benign and reversible state accompanied by a pleasant affect. In contrast, the second HPPD Type we refer to as HPPD II, a generally long-term, distressing, pervasive, either slowly reversible or irreversible, non-benign state accompanied by an unpleasant affect. HPPD I and II appear to be part of a broad spectrum of non-psychopathological and psychopathological states reported by hallucinogen users. HPPD I and II may be clinically characterized by prodromal symptoms, onset, content of visual imagery, precipitators, frequency, duration and intensity of perceptual recurrences, severity, course, differential diagnosis, accompanying mood and affect, insight and remission. Pharmacological therapy with or without preceding or following co-occurring psychiatric disorders have been shown to ameliorate this syndrome. A large variety of medications may be utilized to alleviate this condition, but with differential results suggesting several subtypes. The purpose of this manuscript is to provide a clinical-oriented, comprehensive and concise review to treating psychiatrists.

How many forms of perseveration? Evidence from cancellation tasks in right hemisphere patients.

Neglect patients' performance during cancellation tasks is characterized by left sided omissions and, in many cases, by the production of inappropriate material of various kinds in the ipsilesional space, e.g. additional marks over already cancelled targets, marks drawn away from targets, scribbles, irrelevant drawings. It is unclear whether these behaviours, which have collectively been called perseverative, are functionally and anatomically connected and whether they correlate with the severity of neglect. Here we report a retrospective study on 33 right brain damaged patients with neglect after right hemisphere lesions in whom we measured the intensity of perseveration of the three following kinds: (1) 'additional marks' (AM) perseveration where patients cancelled a target with two or more well separated marks; (2) 'scribble' perseveration, where patients, instead of cancelling the target with a single pen stroke as required by the task, performed multiple pen strokes without breaking the pen-to-paper contact, with the final product being a scribble; (3) 'flying marks' (FM) perseveration where patients produced cancellation marks well away from the targets. We found that AM and FM perseveration correlated with neglect severity, while 'scribble' perseveration did not. The lesion-symptom mapping showed three separate anatomical areas in the right hemisphere: 'scribble' perseveration was associated with lesions of the orbitofrontal cortex and caudate nucleus; AM perseveration was associated with damage to the rolandic operculum, superior temporal gyrus and inferior frontal gyrus; FM perseveration was associated with damage to the dorsal premotor cortex and the temporal pole. Neglect severity followed damage to a region which grossly corresponds to the sum of the regions associated with AM and FM perseveration respectively. This complex behavioural and anatomical pattern is interpreted in terms of a three-factor model, in which AM perseveration is caused by a deficit of disengagement of attention from the right side (also causing omissions), FM perseveration is caused by directional hypokinesia (also causing left-side omissions), and 'scribble' perseveration is the consequence of a failure to inhibit an initiated motor act, which is completely separate (both anatomically and functionally) from the disorder inducing omissions.

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.

Specular vision-touch synaesthesia: two reference frames.

Two subtypes of vision-touch synaesthesia (VTS) have been identified. For anatomical VTS, sight of touch on another person elicits synaesthetic tactile sensation at the same location on the observer's own body (e.g., viewed touch on the left cheek elicits sensation on the observer's left cheek). For specular VTS, sight of touch on another person elicits synaesthetic tactile sensation at the mirror-reflected location (e.g., viewed touch on the left cheek elicits sensation on the observer's right cheek). Here we report two distinctly different patterns of sensation within the specular subtype. Both participants experienced synaesthetic tactile sensation on their right hand when they viewed unidirectional brushstrokes administered to a prosthetic left hand (positioned with fingers pointing toward the participant), but the direction of sensation matched the viewed touch in a hand-centred (spatial) reference frame for RS and in an external (viewer-centred) reference frame for NC. Competing reference frames affect how individuals with specular VTS experience synaesthetic tactile sensation.

Separating forms of neglect using the Apples Test: validation and functional prediction in chronic and acute stroke.

OBJECTIVE: We report data on the validation and functional correlates of Apples Test, which attempts to differentiate between different forms of unilateral neglect. METHOD: Study 1 presents data from 25 participants with chronic brain lesions who completed the Apples Test and another standard measure of neglect (Star Cancellation). The patients' performance relative to 86 controls was assessed and their relative performance across the two tests compared. Study 2 recruited 115 acute hospital stroke patients who completed the Apples Test as part of the Birmingham University Cognitive Screen procedure. We assessed the relations between the different forms of neglect. Study 3 examined neglect type (as measured by the Apples Test) among the acute stroke group in relation to their activities of daily living abilities and affect. RESULTS: In Study 1 Apples Test scores correlated with Star Cancellation performance, while also differentiating between neglect across the page and neglect of parts of objects. Study 2 confirmed the dissociation from Study 1. "Pure" forms of each type of neglect were equally prevalent after right and left hemisphere lesions, while the presence of both deficits was associated with right hemisphere damage. Study 3 showed that each form of neglect also correlated with other measures of cognition. When compared with pure page-based neglect, object-centered neglect was associated with a lower Barthel score (p < .001), while patients with both forms of neglect had higher level of depression (p < .001) than those with the pure forms. CONCLUSIONS: We conclude that the Apples test provides a clinically applicable measure of different forms of neglect. In addition it is a useful predictor of functional outcome. We discuss the nature of the two forms of neglect diagnosed by the test and the functional implications.

Spatially specific and non-lateralised attention deficits in patients with perceptual and premotor neglect.

BACKGROUND: The relationship of spatially specific and non-lateralised attentional deficits to perceptual and premotor neglect was explored in 25 patients with chronic neglect. The association between severity of neglect and attention deficits was also studied. METHODS: Alertness, selective attention and exploration performance were assessed using a battery of computerised and paper-pencil tests. RESULTS: Perceptual and premotor neglect groups differed in the manifestation of attention deficits in the contralesional and ipsilesional hemispace. Differences in the performance time and accuracy were observed to be a function of neglect severity. CONCLUSION: Paper-pencil tests were more sensitive to assess attention deficits in patients with different neglect types and severities of neglect than computerised tests. Therefore, diagnostic evaluation should include both paper-pencil and computerised assessments in order to identify spatially specific as well as non-lateralised attentional deficits.

Visual neglect following stroke: current concepts and future focus.

Visual neglect is a common, yet frequently overlooked, neurological disorder following stroke characterized by a deficit in attention and appreciation of stimuli on the contralesional side of the body. It has a profound functional impact on affected individuals. A assessment and management of this condition are hindered, however, by the lack of professional awareness and clinical guidelines. Recent evidence suggests that the underlying deficit in visual attention is due to a disrupted internalized representation of the outer world rather than a disorder of sensory inputs. Dysfunction of the cortical domains and white-matter tracts, as well as inter-hemispheric imbalance, have been implicated in the various manifestations of visual neglect. Optimal diagnosis requires careful history-taking from the patient, family, and friends, in addition to clinical assessment with the line bisection test, the star cancellation test, and the Catherine Bergego Scale. Early recognition and prompt rehabilitation employing a multidisciplinary approach is desirable. Although no treatment has been definitively shown to be of benefit, those with promise include prism adaptation, visual scanning therapy, and virtual reality-based techniques. Further high quality research to seek optimum short- and long-term rehabilitative strategies for visual neglect is required.

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.

Body schema and body image--pros and cons.

There seems to be no dimension of bodily awareness that cannot be disrupted. To account for such variety, there is a growing consensus that there are at least two distinct types of body representation that can be impaired, the body schema and the body image. However, the definition of these notions is often unclear. The notion of body image has attracted most controversy because of its lack of unifying positive definition. The notion of body schema, onto which there seems to be a more widespread agreement, also covers a variety of sensorimotor representations. Here, I provide a conceptual analysis of the body schema contrasting it with the body image(s) as well as assess whether (i) the body schema can be specifically impaired, while other types of body representation are preserved; and (ii) the body schema obeys principles that are different from those that apply to other types of body representation.

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.

Neural substrates of visuospatial processing in distinct reference frames: evidence from unilateral spatial neglect.

There is evidence for different levels of visuospatial processing with their own frames of reference: viewer-centered, stimulus-centered, and object-centered. The neural locus of these levels can be explored by examining lesion location in subjects with unilateral spatial neglect (USN) manifest in these reference frames. Most studies regarding the neural locus of USN have treated it as a homogenous syndrome, resulting in conflicting results. In order to further explore the neural locus of visuospatial processes differentiated by frame of reference, we presented a battery of tests to 171 subjects within 48 hr after right supratentorial ischemic stroke before possible structural and/or functional reorganization. The battery included MR perfusion weighted imaging (which shows hypoperfused regions that may be dysfunctional), diffusion weighted imaging (which reveals areas of infarct or dense ischemia shortly after stroke onset), and tests designed to disambiguate between various types of neglect. Results were consistent with a dorsal/ventral stream distinction in egocentric/allocentric processing. We provide evidence that portions of the dorsal stream of visual processing, including the right supramarginal gyrus, are involved in spatial encoding in egocentric coordinates, whereas parts of the ventral stream (including the posterior inferior temporal gyrus) are involved in allocentric encoding.