RESUMEN
Memory impairment imposes a great burden on stroke patients and can be divided into Objective Memory Problems (OMPs) and Subjective Memory Complaints (SMCs). Studies have shown that these do not always co-occur. Possibly, the gap between SMCs and OMPs can be bridged when using a more ecologically valid memory test and considering the impact of other common stroke symptoms such as sensory hypersensitivity (SHS) and fatigue. In the present study, we applied Virtual Reality (VR) to create a sensory-rich environment with real-life stimuli. Memory performance was tested with the 15-Verbal Word Learning Test (VLT). Furthermore, we assessed SMCs (Everyday Memory Questionnaire), and the levels of SHS (Multi-Modal Evaluation of Sensory Sensitivity) and fatigue in the previous month. 31 chronic stroke patients and 32 healthy controls participated. The results showed that participants' memory performance decreased in a sensory-rich compared to a neutral environment. This decrease did not significantly differ between the groups. Interestingly, fatigue and SHS are related to the level of SMC in stroke patients but no such evidence was found in healthy controls. Last, for stroke patients, we found a significant negative correlation between SMCs and memory performance in a sensory-rich environment, but not in a neutral environment. In conclusion, our study implicates that in stroke patients, fatigue and SHS are related to SMCs and that using a sensory-rich VR environment might be a more ecologically valid way to objectify SMCs. However, interpretative caution is warranted due to the absence of sex and age-matched controls and potential selection bias.
RESUMEN
PURPOSE: To assess the impact of glaucoma on perceiving three-dimensional (3D) shapes based on monocular depth cues. STUDY DESIGN: Clinical observational study. METHODS: Twenty glaucoma patients, subjected to binocular visual-field sensitivity (binocular-VFS) tests using a Humphrey Visual Field Analyzer, and 20 age-matched healthy volunteers, underwent two tasks: identifying the nearest vertex of a 3D shape using monocular shading (3D-SfS), texture (3D-SfT), or motion (3D-SfM) cues, and distinguishing elementary one-dimensional (1D) features of these cues. The association of the visual-field index (VFI) of binocular-VFS with 3D shape perception in glaucoma patients was also examined. RESULTS: Glaucoma patients demonstrated reduced accuracy in distinguishing 1D luminance brightness and a larger "error-in-depth" between the perceived and actual depths for 3D-SfM and 3D-SfS compared to healthy volunteers. Six glaucoma patients with a 100% VFI for binocular-VFS exhibited a similar error-in-depth to the other fourteen glaucoma patients; they had a larger error-in-depth for 3D-SfM compared to healthy volunteers. No correlation between the error-in-depth values and the VFI values of binocular-VFS was observed. CONCLUSIONS: The 3D shape perception in glaucoma patients varies based on the depth cue's characteristics. Impaired 1D discrimination and larger thresholds for 3D-SfM in glaucoma patients with a 100% VFI for binocular-VFS indicate more pronounced perceptual deficits of lower-level elementary features for 3D-SfS and higher-level visual processing of 3D shapes for 3D-SfM. The effects of the location and degree of binocular visual-field defects on 3D shape perception remain to be elucidated. Our research provides insights into the 3D shape extraction mechanism in glaucoma.
Asunto(s)
Señales (Psicología) , Percepción de Profundidad , Glaucoma , Visión Binocular , Visión Monocular , Campos Visuales , Humanos , Masculino , Femenino , Percepción de Profundidad/fisiología , Visión Binocular/fisiología , Campos Visuales/fisiología , Persona de Mediana Edad , Anciano , Glaucoma/fisiopatología , Glaucoma/diagnóstico , Visión Monocular/fisiología , Pruebas del Campo Visual , Presión Intraocular/fisiología , Percepción de Forma/fisiología , AdultoRESUMEN
Objective: Although neurocognitive disorders (NCD) are common post-stroke, many populations do not have adapted cognitive screens and cut-offs. We therefore reviewed the appropriateness of the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and Oxford Cognitive Screen (OCS) for diagnosing NCD in culturally diverse stroke populations. Method: Using an extensive search string, diagnostic accuracy studies for MMSE, MoCA and OCS in the stroke population were retrieved from four databases. We compared translations and adaptations, adjustments in scores and cut-offs, and their diagnostic accuracy. Results: The search resulted in 28 MMSE, 39 MoCA and 5 OCS-studies in 13 western, educated, industrialized, rich and democratic (WEIRD) and 4 other countries. There was a lack of studies on South-American, African, and non-Chinese-Asian populations. All three tests needed adaptation for less WEIRD populations and populations with languages with non-Latin features. Optimal MMSE and OCS subtest cut-offs were similar across WEIRD and less WEIRD populations, whereas optimal MoCA cut-offs appeared lower for less WEIRD populations. The use of adjusted scores resulted in different optimal cut-offs or similar cut-offs with better accuracy. Conclusions: MoCA, MMSE and OCS are promising tools for diagnosing post-stroke-NCD. For culturally diverse populations, translation, adaptation and adjusted scores or cut-offs are necessary for diagnostic accuracy. Available studies report scarcely about their sample's cultural background and there is a lack of diagnostic accuracy studies in less WEIRD or culturally diverse populations. Future studies should report more cultural characteristics of their sample to provide better insight into the tests' accuracy in culturally diverse populations.
Asunto(s)
Trastornos del Conocimiento , Disfunción Cognitiva , Accidente Cerebrovascular , Humanos , Disfunción Cognitiva/diagnóstico , Pruebas Neuropsicológicas , Accidente Cerebrovascular/complicaciones , Trastornos del Conocimiento/diagnóstico , Trastornos NeurocognitivosRESUMEN
Objective: Sensory hypersensitivity is common after acquired brain injury. Since appropriate diagnostic tools are lacking, these complaints are overlooked by clinicians and available literature is limited to light and noise hypersensitivity after concussion. This study aimed to investigate the prevalence of sensory hypersensitivity in other modalities and after other types of brain injury. Method: We developed the Multi-Modal Evaluation of Sensory Sensitivity (MESSY), a patient-friendly questionnaire that assesses sensory sensitivity across multiple sensory modalities. 818 neurotypical adults (mean age = 49; 244 male) and 341 chronic acquired brain injury patients (including stroke, traumatic brain injury, and brain tumour patients) (mean age = 56; 126 male) completed the MESSY online. Results: The MESSY had a high validity and reliability in neurotypical adults. Post-injury sensory hypersensitivity (examined using open-ended questions) was reported by 76% of the stroke patients, 89% of the traumatic brain injury patients, and 82% of the brain tumour patients. These complaints occurred across all modalities with multisensory, visual, and auditory hypersensitivity being the most prevalent. Patients with post-injury sensory hypersensitivity reported a higher sensory sensitivity severity on the multiple-choice items of the MESSY as compared to neurotypical adults and acquired brain injury patients without post-injury sensory hypersensitivity (across all sensory modalities) (effect sizes (partial eta squared) ranged from .06 to .22). Conclusions: These results show that sensory hypersensitivity is prevalent after different types of acquired brain injury as well as across several sensory modalities. The MESSY can improve recognition of these symptoms and facilitate further research.
Asunto(s)
Conmoción Encefálica , Lesiones Traumáticas del Encéfalo , Neoplasias Encefálicas , Accidente Cerebrovascular , Adulto , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Pruebas Neuropsicológicas , Conmoción Encefálica/diagnósticoRESUMEN
Feature-based attention allows to efficiently guide attention to relevant information in the visual scene, but unambiguous empirical evidence on age-related effects is still limited. In this study, young and older participants performed a two-alternative forced choice task in which a response was selected based on a task-relevant number (=target) presented alone or with a task-irrelevant letter (=neutral distracter) or number (=compatible/incompatible distracter). Participants were required to select the target based on color. To compare the behavioral interference of the distracters between the age groups, data were modeled with a hierarchical drift-diffusion model. The results revealed that decreases in the rate at which information was collected in the conditions with versus without a distracter were more pronounced in the older than young age group when the distracter was compatible or incompatible. Our findings are consistent with an age-related decline in the ability to filter out distracters based on features.
RESUMEN
Many activities in daily life rely on the ability to continuously keep attention on task requirements. Patients with acquired brain injury often suffer from deficits in sustained attention that impact quality of life and complicate rehabilitation. The sustained attention to response task (SART) is a commonly used go/no-go task in the assessment of sustained attention. However, its feasibility for patients with acquired brain injury could be questioned considering deficits in alphanumerical processing following brain damage. We investigated whether a SART with sinusoidal gratings instead of digits can be used to assess sustained attention. The Gratings SART and Digits SART were administered in a random and fixed sequence to 48 cognitively healthy participants. Performance of the neurotypical individuals on the random and fixed Gratings SART was only moderately different from and correlated with performance on the random and fixed Digits SART. As a proof of concept, the SARTs were also administered to 11 cases with acquired brain injury. Performance in the random and fixed variants of both the Gratings SART and Digits SART was sensitive to cognitive impairments of cases with acquired brain injury. In conclusion, the SART with sinusoidal gratings holds promise as a tool to (re-)assess sustained attention in clinical practice. Further research is critical to investigate whether its performance accurately predicts sustained attention in daily life since we failed to find a significant correlation between performance on any of the SARTs and a self-reported measure of sustained attention.
RESUMEN
It is commonly asserted that MRI-derived lesion masks outperform CT-derived lesion masks in lesion-mapping analysis. However, no quantitative analysis has been conducted to support or refute this claim. This study reports an objective comparison of lesion-mapping analyses based on CT- and MRI-derived lesion masks to clarify how input imaging type may ultimately impact analysis results. Routine CT and MRI data were collected from 85 acute stroke survivors. These data were employed to create binarized lesion masks and conduct lesion-mapping analyses on simulated behavioral data. Following standard lesion-mapping analysis methodology, each voxel or region of interest (ROI) were considered as the underlying "target" within CT and MRI data independently. The resulting thresholded z-maps were compared between matched CT- and MRI-based analyses. Paired MRI- and CT-derived lesion masks were found to exhibit significant variance in location, overlap, and size. In ROI-level simulations, both CT and MRI-derived analyses yielded low Dice similarity coefficients, but CT analyses yielded a significantly higher proportion of results which overlapped with target ROIs. In single-voxel simulations, MRI-based lesion mapping was able to include more voxels than CT-based analyses, but CT-based analysis results were closer to the underlying target voxel. Simulated lesion-symptom mapping results yielded by paired CT and MRI lesion-symptom mapping analyses demonstrated moderate agreement in terms of Dice coefficient when systematic differences in cluster size and lesion overlay are considered. Overall, these results suggest that CT and MR-derived lesion-symptom mapping results do not reliably differ in accuracy. This finding is critically important as it suggests that future studies can employ CT-derived lesion masks if these scans are available within the appropriate time-window.
Asunto(s)
Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/patología , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: Cognitive functioning is increasingly assessed as a secondary outcome in neuro-oncological trials. However, which cognitive domains or tests to assess, remains debatable. In this meta-analysis, we aimed to elucidate the longer-term test-specific cognitive outcomes in adult glioma patients. METHODS: A systematic search yielded 7098 articles for screening. To investigate cognitive changes in glioma patients and differences between patients and controls 1-year follow-up, random-effects meta-analyses were conducted per cognitive test, separately for studies with a longitudinal and cross-sectional design. A meta-regression analysis with a moderator for interval testing (additional cognitive testing between baseline and 1-year posttreatment) was performed to investigate the impact of practice in longitudinal designs. RESULTS: Eighty-three studies were reviewed, of which 37 were analyzed in the meta-analysis, involving 4078 patients. In longitudinal designs, semantic fluency was the most sensitive test to detect cognitive decline over time. Cognitive performance on mini-mental state exam (MMSE), digit span forward, phonemic and semantic fluency declined over time in patients who had no interval testing. In cross-sectional studies, patients performed worse than controls on the MMSE, digit span backward, semantic fluency, Stroop speed interference task, trail-making test B, and finger tapping. CONCLUSIONS: Cognitive performance of glioma patients 1 year after treatment is significantly lower compared to the norm, with specific tests potentially being more sensitive. Cognitive decline over time occurs as well, but can easily be overlooked in longitudinal designs due to practice effects (as a result of interval testing). It is warranted to sufficiently correct for practice effects in future longitudinal trials.
Asunto(s)
Trastornos del Conocimiento , Glioma , Humanos , Adulto , Trastornos del Conocimiento/diagnóstico , Estudios Transversales , Cognición , Pruebas Neuropsicológicas , Glioma/complicaciones , Glioma/terapia , Terapia CombinadaRESUMEN
Patients with acquired brain injury frequently report experiencing sensory stimuli as abnormally under- (sensory hyposensitivity) or overwhelming (sensory hypersensitivity). Although they can negatively impact daily functioning, these symptoms are poorly understood. To provide an overview of the current evidence on atypical sensory sensitivity after acquired brain injury, we conducted a systematic literature review. The primary aim of the review was to investigate the behavioural and neural mechanisms that are associated with self-reported sensory sensitivity. Studies were included when they studied sensory sensitivity in acquired brain injury populations, and excluded when they were not written in English, consisted of non-empirical research, did not study human subjects, studied pain, related sensory sensitivity to peripheral injury or studied patients with a neurodegenerative disorder, meningitis, encephalitis or a brain tumour. The Web of Science, PubMed and Scopus databases were searched for appropriate studies. A qualitative synthesis of the results of the 81 studies that were included suggests that abnormal sensory thresholds and a reduced information processing speed are candidate behavioural mechanisms of atypical subjective sensory sensitivity after acquired brain injury. Furthermore, there was evidence for an association between subjective sensory sensitivity and structural grey or white matter abnormalities, and to functional abnormalities in sensory cortices. However, further research is needed to explore the causation of atypical sensory sensitivity. In addition, there is a need for the development of adequate diagnostic tools. This can significantly advance the quantity and quality of research on the prevalence, aetiology, prognosis and treatment of these symptoms.
Asunto(s)
Lesiones Encefálicas , Trastornos de la Sensación , Humanos , Lesiones Encefálicas/complicaciones , Trastornos de la Sensación/etiologíaRESUMEN
BACKGROUND AND PURPOSE: The Oxford Cognitive Screen is a stroke-specific screen to evaluate attention, executive functions, memory, praxis, language, and numeric cognition. It was originally validated in England for acute stroke patients. In this study, we examined the psychometric properties of the Dutch OCS (OCS-NL). METHODS: A total of 193 (99 acute stroke unit, 94 rehabilitation unit) patients were included in our study. A subset of patients (n = 128) completed a retest with the parallel version of the OCS-NL. RESULTS: First, we did not find evidence for a difference in prevalence of impairment between patients in the acute stroke versus rehabilitation unit on all but one of the subtests. For praxis, we observed a 14% lower prevalence of impairment in the rehabilitation than the acute stroke unit. Second, the parallel-form reliability ranged from weak to excellent across subtests. Third, in stroke patients below age 60, the OCS-NL had a 92% sensitivity relative to the MoCA, while the MoCA had a 55% sensitivity relative to the OCS-NL. Last, although left-hemispheric stroke patients performed worse on almost all MoCA subdomains, they performed similarly to right-hemispheric stroke patients on non-language domains on the OCS-NL. CONCLUSIONS: Our results suggest that the OCS-NL is a reliable cognitive screen that can be used in acute stroke and rehabilitation units. The OCS-NL may be more sensitive to detect cognitive impairment in young stroke patients and less likely to underestimate cognitive abilities in left-hemispheric stroke patients than the MoCA.
Asunto(s)
Trastornos del Conocimiento , Disfunción Cognitiva , Accidente Cerebrovascular , Humanos , Persona de Mediana Edad , Psicometría , Pruebas Neuropsicológicas , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/psicología , Reproducibilidad de los Resultados , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología , Sobrevivientes , Cognición , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/etiologíaRESUMEN
In day-to-day dynamic activities where sensory input is abundant, stimulus representations in the visual cortex are modulated based on their attentional priority. Several studies have established the top-down role of a fronto-parietal dorsal attention network in selective attention. In the current study, we aimed to investigate whether activity of subregions of this network and the visual cortex is modulated by feature-based attentional weighting, and if so, whether their timecourses of activity are correlated. To this end, we analyzed fMRI data of 28 healthy subjects, who performed a feature-based go/no-go task. Participants had to attend to one or two colored streams of sinusoidal gratings and respond to each grating in the task-relevant stream(s) except to a single non-target grating. Univariate and multivariate fMRI results indicated that activity in bilateral fronto-parietal (frontal eye fields, intraparietal sulcus and superior parietal lobe) and visual (V1-V4, lateral occipital cortex and fusiform gyrus) regions was modulated by selecting one instead of attending to two gratings. Functional connectivity was not significantly different between fronto-parietal and visual regions when attending to one as opposed to two gratings. Our study demonstrates that activity in subregions of both the fronto-parietal and visual cortex is modified by feature-based attentional weighting.
RESUMEN
Immersive virtual reality (IVR) may boost neglect recovery, as it can provide an engaging experience in a 3D environment. We designed an IVR rehabilitation game for neglect patients using the Oculus Rift. Multisensory cues were presented in the neglected visual field in a patient-tailored way. We acquired pilot data in 15 neurologically healthy controls and 7 stroke patients. First, we compared cybersickness before and after VR exposure. Second, we assessed the user experience through a questionnaire. Third, we tested whether neglect symptoms corresponded between the VR game and a computerized cancelation task. Fourth, we evaluated the effect of the multisensory cueing on target discrimination. Last, we tested two algorithms to tailor the game to the characteristics of the neglected visual field. Cybersickness significantly reduced after VR exposure in six stroke patients and was low in healthy controls. Patients rated the user experience neutral to positive. In addition, neglect symptoms were consistent between a computerized cancelation and VR rehabilitation task. The multisensory cue positively affected target discrimination in the game and we successfully presented sensory stimulation to the neglected visual field in a patient-tailored way. Our results show that it is promising to use gamified patient-tailored immersive VR for neglect rehabilitation.
Asunto(s)
Trastornos de la Percepción , Accidente Cerebrovascular , Realidad Virtual , Atención/fisiología , Estudios de Factibilidad , Humanos , Trastornos de la Percepción/diagnóstico , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnósticoRESUMEN
Breast cancer treatment can induce alterations in blood- and neuroimaging-based markers. However, an overview of the predictive value of these markers for cognition is lacking for breast cancer survivors. This systematic review summarized studies of the last decade, using the PubMed database, evaluating blood markers, and the association between blood- or structural neuroimaging markers and cognition across the chemotherapy trajectory for primary breast cancer, following PRISMA guidelines. Forty-four studies were included. Differences were observed in all blood marker categories, from on-therapy until years post-chemotherapy. Associations were found between cognitive functioning and (1) blood markers (mainly inflammation-related) during, shortly-, or years post-chemotherapy and (2) white and gray matter metrics in frontal, temporal and parietal brain regions months up until years post-chemotherapy. Preliminary evidence exists for epigenetic and metabolic changes being associated with cognition, only after chemotherapy. This review demonstrated time-dependent associations between specific blood-based and structural neuroimaging markers with cognitive impairment in patients with breast cancer. Future studies are encouraged to include both neuroimaging- and blood markers (e.g. of neuronal integrity, epigenetics and metabolism) to predict long-term cognitive effects of chemotherapy.
RESUMEN
OBJECTIVE: Clinical neuropsychology has been slow in adopting novelties in psychometrics, statistics, and technology. Researchers have indicated that the stationary nature of clinical neuropsychology endangers its evidence-based character. In addition to a technological crisis, there may be a statistical crisis affecting clinical neuropsychology. That is, the frequentist null hypothesis significance testing framework remains the dominant approach in clinical practice, despite a recent surge in critique on this framework. While the Bayesian framework has been put forward as a viable alternative in psychology in general, the possibilities it offers to clinical neuropsychology have not received much attention. METHOD: In the current position paper, we discuss and reflect on the value of Bayesian methods for the advancement of evidence-based clinical neuropsychology. RESULTS: We aim to familiarize clinical neuropsychologists and neuropsychological researchers to Bayesian methods of inference and provide a clear rationale for why these methods are valuable for clinical neuropsychology. CONCLUSION: We argue that Bayesian methods allow for a more intuitive answer to our diagnostic questions and form a more solid foundation for sequential and adaptive diagnostic testing, representing uncertainty about patients' observed test scores and cognitive modeling of test results.
Asunto(s)
Neuropsicología , Teorema de Bayes , Humanos , Pruebas Neuropsicológicas , Neuropsicología/métodos , PsicometríaRESUMEN
Visuospatial neglect is a heterogenous syndrome which can occur following damage to either right or left hemisphere areas. This study employs voxel-lesion symptom mapping to identify the neural correlates of left and right egocentric and allocentric neglect in a large acute stroke cohort. A cohort of 446 acute stroke survivors (age = 26-95, 44% female) completed neuropsychological neglect assessment and routine clinical imaging. Similar to previous investigations, left egocentric and left allocentric neglect were associated with damage to distinct clusters of voxels within the posterior parietal and temporo-parietal junction areas. Unlike previous investigations, right egocentric neglect was found to most strongly associated with damage to more posterior voxels within left occipital cortical areas. Right allocentric neglect was found to be most strongly associated with damage to the anterior limb of the left internal capsule. Interestingly, the right hemisphere homologues of the areas implicated in right-lateralised neglect were not overlapping with those associated with left neglect impairment. This dissociation was present across both egocentric and allocentric neglect impairment. The results of this investigation suggest that right egocentric/allocentric neglect should not be characterised as a consequence of damage to left-hemisphere homologues of the right hemisphere attentional systems. These findings support the characterisation of visuospatial neglect as a heterogenous cluster of impairments rather than a unitary syndrome and provide novel insight into the neural correlates of spatial attention.
Asunto(s)
Trastornos de la Percepción , Accidente Cerebrovascular , Adulto , Anciano , Anciano de 80 o más Años , Atención , Mapeo Encefálico , Corteza Cerebral , Femenino , Lateralidad Funcional , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Trastornos de la Percepción/diagnóstico por imagen , Trastornos de la Percepción/etiología , Percepción Espacial , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagenRESUMEN
Background/Objective. This study aims to investigate how complex visuospatial neglect behavioural phenotypes predict long-term outcomes, both in terms of neglect recovery and broader functional outcomes after 6 months post-stroke. Methods. This study presents a secondary cohort study of acute and 6-month follow-up data from 400 stroke survivors who completed the Oxford Cognitive Screen's Cancellation Task. At follow-up, patients also completed the Stroke Impact Scale questionnaire. These data were analysed to identify whether any specific combination of neglect symptoms is more likely to result in long-lasting neglect or higher levels of functional impairment, therefore warranting more targeted rehabilitation. Results. Overall, 98/142 (69%) neglect cases recovered by follow-up, and there was no significant difference in the persistence of egocentric/allocentric (X2 [1] = .66 and P = .418) or left/right neglect (X2 [2] = .781 and P = .677). Egocentric neglect was found to follow a proportional recovery pattern with all patients demonstrating a similar level of improvement over time. Conversely, allocentric neglect followed a non-proportional recovery pattern with chronic neglect patients exhibiting a slower rate of improvement than those who recovered. A multiple regression analysis revealed that the initial severity of acute allocentric, but not egocentric, neglect impairment acted as a significant predictor of poor long-term functional outcomes (F [9,300] = 4.742, P < .001 and adjusted R2 = .098). Conclusions. Our findings call for systematic neuropsychological assessment of both egocentric and allocentric neglect following stroke, as the occurrence and severity of these conditions may help predict recovery outcomes over and above stroke severity alone.
Asunto(s)
Trastornos de la Percepción/fisiopatología , Desempeño Psicomotor/fisiología , Recuperación de la Función/fisiología , Percepción Espacial/fisiología , Accidente Cerebrovascular/fisiopatología , Anciano , Anciano de 80 o más Años , Atención/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas NeuropsicológicasRESUMEN
Virtual reality (VR) offers many opportunities for post-stroke rehabilitation. However, "VR" can refer to several types of computer-based rehabilitation systems. Since these systems may impact the feasibility and the efficacy of VR interventions, consistent terminology is important. In this study, we aimed to optimize the terminology for VR-based post-stroke rehabilitation by assessing whether and how review papers on this topic defined VR and what types of mixed reality systems were discussed. In addition, this review can inspire the use of consistent terminology for other researchers working with VR. We assessed the use of the term VR in review papers on post-stroke rehabilitation extracted from Scopus, Web of Science and PubMed. We also developed a taxonomy distinguishing 16 mixed reality systems based on three factors: immersive versus semi-immersive displays, the way in which real and virtual information is mixed, and the main input device. 64% of the included review papers (N = 121) explicitly defined VR and 33% of them described different subtypes of VR, with immersive and non-immersive VR as the most common distinction. The most frequently discussed input devices were motion-capture cameras and handheld devices, while regular 2D monitors were the most frequently mentioned output devices. Our analysis revealed that reviews on post-stroke VR rehabilitation did not or only broadly defined "VR" and did not focus on a specific system. Since the efficacy and feasibility of rehabilitation may depend on the specific system, we propose a new data-driven taxonomy to distinguish different systems, which is expected to facilitate communication amongst researchers and clinicians working with virtual reality.
RESUMEN
Methotrexate (MTX) is associated with leukoencephalopathy (LE) in children treated for lymphoblastic leukemia/lymphoma (ALL/LBL). However, large-scale studies with systematic MR acquisition and quantitative volumetric lesion information remain limited. Hence, the prevalence of lesion burdens and the potential risk factors of LE in this population are still inconclusive. FLAIR-MRI scans were acquired at the end of treatment in children who were treated for ALL/LBL, which were quantitatively analyzed for LE. Voxels were assigned to the lesion segmentation if indicated by two raters. Logistic and linear regression models were used to test whether lesion presence and size were predicted by risk factors such as age at diagnosis, gender, intrathecal (IT-) or intravenous (IV-)MTX dose, CNS invasion, and acute neurological events. Patients with a pre-existing neurological condition or low-quality MR scan were excluded from the analyses. Of the 129 patients, ten (8%) suffered from CNS invasion. Chemotherapy-associated neurological events were observed in 13 patients (10%) during therapy, and 68 patients (53%) showed LE post-treatment. LE was more frequent in cases of lower age and higher cumulative IV-MTX doses, while the extent of LE and neurological symptoms were associated only with IV-MTX doses. Neurological events were not significantly associated with LE, even though symptomatic patients demonstrated a higher ratio of LE (n = 9/13) than asymptomatic patients (n = 59/116). This study suggests leukoencephalopathy frequently occurs in both symptomatic and asymptomatic leukemia patients. Younger children and patients treated with higher cumulative IV-MTX doses might need more regular screening for early detection and follow-up of associated sequelae.
RESUMEN
OBJECTIVE: Visual attention helps us to selectively process relevant information and is crucial in our everyday interactions with the environment. Not surprisingly, it is one of the cognitive domains that is most frequently affected by acquired brain injury. Reliable assessment of attention deficits is pivotal to neuropsychological examination and helps to optimize individual rehabilitation plans. Compared with conventional pen-and-paper tests, computerized tasks borrowed from the field of experimental psychology bring many benefits, but lab-based experimental setups cannot be easily incorporated in clinical practice. Light-weight and portable mobile tablet devices may facilitate the translation of computerized tasks to clinical settings. One such task is based on the Theory of Visual Attention (TVA), a mathematical model of visual attention. TVA-based paradigms have been widely used to investigate several aspects of visual attention in both fundamental and clinical research, and include measures for general processing capacity as well as stimulus-specific attentional parameters. METHODS: This article discusses the benefits of TVA-based assessments compared with frequently used neuropsychological tests of visual attention, and examines the reliability of a tablet-based TVA-based assessment in 59 neurologically healthy participants. RESULTS: Pearson's correlations indicate that the tablet-based TVA assessment and the conventional lab-based TVA assessment have a comparable parallel-form (range: .67-.93), test-retest (range: .61-.78), and internal reliability (range: .56-.97). CONCLUSION: Our results suggest that tablet-based TVA assessment may be a promising tool to acquire clinical measures of visual attention at low cost at the bedside of the patient.