Joint impact on attention, alertness and inhibition of lesions at a frontal white matter crossroad.

In everyday life, information from different cognitive domains-such as visuospatial attention, alertness and inhibition-needs to be integrated between different brain regions. Early models suggested that completely segregated brain networks control these three cognitive domains. However, more recent accounts, mainly based on neuroimaging data in healthy participants, indicate that different tasks lead to specific patterns of activation within the same, higher-order and 'multiple-demand' network. If so, then a lesion to critical substrates of this common network should determine a concomitant impairment in all three cognitive domains. The aim of the present study was to critically investigate this hypothesis, i.e. to identify focal stroke lesions within the network that can concomitantly affect visuospatial attention, alertness and inhibition. We studied an unselected sample of 60 first-ever right-hemispheric, subacute stroke patients using a data-driven, bottom-up approach. Patients performed 12 standardized neuropsychological and oculomotor tests, four per cognitive domain. A principal component analysis revealed a strong relationship between all three cognitive domains: 10 of 12 tests loaded on a first, common component. Analysis of the neuroanatomical lesion correlates using different approaches (i.e. voxel-based and tractwise lesion-symptom mapping, disconnectome maps) provided convergent evidence on the association between severe impairment of this common component and lesions at the intersection of superior longitudinal fasciculus II and III, frontal aslant tract and, to a lesser extent, the putamen and inferior fronto-occipital fasciculus. Moreover, patients with a lesion involving this region were significantly more impaired in daily living cognition, which provides an ecological validation of our results. A probabilistic functional atlas of the multiple-demand network was performed to confirm the potential relationship between patients' lesion substrates and observed cognitive impairments as a function of the multiple-demand network connectivity disruption. These findings show, for the first time, that a lesion to a specific white matter crossroad can determine a concurrent breakdown in all three considered cognitive domains. Our results support the multiple-demand network model, proposing that different cognitive operations depend on specific collaborators and their interaction, within the same underlying neural network. Our findings also extend this hypothesis by showing (i) the contribution of superior longitudinal fasciculus and frontal aslant tract to the multiple-demand network; and (ii) a critical neuroanatomical intersection, crossed by a vast amount of long-range white matter tracts, many of which interconnect cortical areas of the multiple-demand network. The vulnerability of this crossroad to stroke has specific cognitive and clinical consequences; this has the potential to influence future rehabilitative approaches.

A Transferable Lidar-Based Method to Conduct Contactless Assessments of Gait Parameters in Diverse Home-like Environments.

Gait abnormalities in older adults are linked to increased risks of falls, institutionalization, and mortality, necessitating accurate and frequent gait assessments beyond traditional clinical settings. Current methods, such as pressure-sensitive walkways, often lack the continuous natural environment monitoring needed to understand an individual's gait fully during their daily activities. To address this gap, we present a Lidar-based method capable of unobtrusively and continuously tracking human leg movements in diverse home-like environments, aiming to match the accuracy of a clinical reference measurement system. We developed a calibration-free step extraction algorithm based on mathematical morphology to realize Lidar-based gait analysis. Clinical gait parameters of 45 healthy individuals were measured using Lidar and reference systems (a pressure-sensitive walkway and a video recording system). Each participant participated in three predefined ambulation experiments by walking over the walkway. We observed linear relationships with strong positive correlations (R2>0.9) between the values of the gait parameters (step and stride length, step and stride time, cadence, and velocity) measured with the Lidar sensors and the pressure-sensitive walkway reference system. Moreover, the lower and upper 95% confidence intervals of all gait parameters were tight. The proposed algorithm can accurately derive gait parameters from Lidar data captured in home-like environments, with a performance not significantly less accurate than clinical reference systems.

An Overview of Wearable Haptic Technologies and Their Performance in Virtual Object Exploration.

We often interact with our environment through manual handling of objects and exploration of their properties. Object properties (OP), such as texture, stiffness, size, shape, temperature, weight, and orientation provide necessary information to successfully perform interactions. The human haptic perception system plays a key role in this. As virtual reality (VR) has been a growing field of interest with many applications, adding haptic feedback to virtual experiences is another step towards more realistic virtual interactions. However, integrating haptics in a realistic manner, requires complex technological solutions and actual user-testing in virtual environments (VEs) for verification. This review provides a comprehensive overview of recent wearable haptic devices (HDs) categorized by the OP exploration for which they have been verified in a VE. We found 13 studies which specifically addressed user-testing of wearable HDs in healthy subjects. We map and discuss the different technological solutions for different OP exploration which are useful for the design of future haptic object interactions in VR, and provide future recommendations.

Eigenbehaviour as an Indicator of Cognitive Abilities.

With growing use of machine learning algorithms and big data in health applications, digital measures, such as digital biomarkers, have become highly relevant in digital health. In this paper, we focus on one important use case, the long-term continuous monitoring of cognitive ability in older adults. Cognitive ability is a factor both for long-term monitoring of people living alone as well as a relevant outcome in clinical studies. In this work, we propose a new potential digital biomarker for cognitive abilities based on location eigenbehaviour obtained from contactless ambient sensors. Indoor location information obtained from passive infrared sensors is used to build a location matrix covering several weeks of measurement. Based on the eigenvectors of this matrix, the reconstruction error is calculated for various numbers of used eigenvectors. The reconstruction error in turn is used to predict cognitive ability scores collected at baseline, using linear regression. Additionally, classification of normal versus pathological cognition level is performed using a support-vector machine. Prediction performance is strong for high levels of cognitive ability but grows weaker for low levels of cognitive ability. Classification into normal and older adults with mild cognitive impairment, using age and the reconstruction error, shows high discriminative performance with an ROC AUC of 0.94. This is an improvement of 0.08 as compared with a classification with age only. Due to the unobtrusive method of measurement, this potential digital biomarker of cognitive ability can be obtained entirely unobtrusively-it does not impose any patient burden. In conclusion, the usage of the reconstruction error is a strong potential digital biomarker for binary classification and, to a lesser extent, for more detailed prediction of inter-individual differences in cognition.

Usability of Two New Interactive Game Sensor-Based Hand Training Devices in Parkinson's Disease.

This pilot cross-sectional study aimed to evaluate the usability of two new interactive game sensor-based hand devices (GripAble and Smart Sensor Egg) in both healthy adults as well as in persons with Parkinson's Disease (PD). Eight healthy adults and eight persons with PD participated in this study. Besides a standardised usability measure, the state of flow after one training session and the effect of cognitive abilities on flow were evaluated. High system usability scores (SUS) were obtained both in healthy participants (72.5, IQR = 64.375-90, GripAble) as well as persons with PD (77.5, IQR = 70-80.625, GripAble; 77.5, IQR = 75-82.5, Smart Sensor Egg). Similarly, high FSSOT scores were achieved after one training session (42.5, IQR = 39.75-50, GripAble; 50, IQR = 47-50, Smart Sensor Egg; maximum score 55). Across both groups, FSSOT scores correlated significantly with SUS scores (r = 0.52, p = 0.039). Finally, MoCA did not correlate significantly with FSSOT scores (r = 0.02, p = 0.9). The present study shows high usability for both interactive game sensor-based hand training devices, for persons with PD and healthy participants.

An Instrumented Apartment to Monitor Human Behavior: A Pilot Case Study in the NeuroTec Loft.

For patients suffering from neurodegenerative disorders, the behavior and activities of daily living are an indicator of a change in health status, and home-monitoring over a prolonged period of time by unobtrusive sensors is a promising technology to foster independent living and maintain quality of life. The aim of this pilot case study was the development of a multi-sensor system in an apartment to unobtrusively monitor patients at home during the day and night. The developed system is based on unobtrusive sensors using basic technologies and gold-standard medical devices measuring physiological (e.g., mobile electrocardiogram), movement (e.g., motion tracking system), and environmental parameters (e.g., temperature). The system was evaluated during one session by a healthy 32-year-old male, and results showed that the sensor system measured accurately during the participant's stay. Furthermore, the participant did not report any negative experiences. Overall, the multi-sensor system has great potential to bridge the gap between laboratories and older adults' homes and thus for a deep and novel understanding of human behavioral and neurological disorders. Finally, this new understanding could be utilized to develop new algorithms and sensor systems to address problems and increase the quality of life of our aging society and patients with neurological disorders.

Getting into a "Flow" state: a systematic review of flow experience in neurological diseases.

BACKGROUND: Flow is a subjective psychological state that people report when they are fully involved in an activity to the point of forgetting time and their surrounding except the activity itself. Being in flow during physical/cognitive rehabilitation may have a considerable impact on functional outcome, especially when patients with neurological diseases engage in exercises using robotics, virtual/augmented reality, or serious games on tablets/computer. When developing new therapy games, measuring flow experience can indicate whether the game motivates one to train. The purpose of this study was to identify and systematically review current literature on flow experience assessed in patients with stroke, traumatic brain injury, multiple sclerosis and Parkinson's disease. Additionally, we critically appraised, compared and summarized the measurement properties of self-reported flow questionnaires used in neurorehabilitation setting. DESIGN: A systematic review using PRISMA and COSMIN guidelines. METHODS: MEDLINE Ovid, EMBASE Ovid, CINAHL EBSCO, SCOPUS were searched. Inclusion criteria were (1) peer-reviewed studies that (2) focused on the investigation of flow experience in (3) patients with neurological diseases (i.e., stroke, traumatic brain injury, multiple sclerosis and/or Parkinson's disease). A qualitative data synthesis was performed to present the measurement properties of the used flow questionnaires. RESULTS: Ten studies out of 911 records met the inclusion criteria. Seven studies measured flow in the context of serious games in patients with stroke, traumatic brain injury, multiple sclerosis and Parkinson's disease. Three studies assessed flow in other activities than gaming (song-writing intervention and activities of daily living). Six different flow questionnaires were used, all of which were originally validated in healthy people. None of the studies presented psychometric data in their respective research population. CONCLUSION: The present review indicates that flow experience is increasingly measured in the physical/cognitive rehabilitation setting in patients with neurological diseases. However, psychometric properties of used flow questionnaires are lacking. For exergame developers working in the field of physical/cognitive rehabilitation in patients with neurological diseases, a valid flow questionnaire can help to further optimize the content of the games so that optimal engagement can occur during the gameplay. Whether flow experiences can ultimately have positive effects on physical/cognitive parameters needs further study.

Contactless Gait Assessment in Home-like Environments.

Gait analysis is an important part of assessments for a variety of health conditions, specifically neurodegenerative diseases. Currently, most methods for gait assessment are based on manual scoring of certain tasks or restrictive technologies. We present an unobtrusive sensor system based on light detection and ranging sensor technology for use in home-like environments. In our evaluation, we compared six different gait parameters, based on recordings from 25 different people performing eight different walks each, resulting in 200 unique measurements. We compared the proposed sensor system against two state-of-the art technologies, a pressure mat and a set of inertial measurement unit sensors. In addition to test usability and long-term measurement, multi-hour recordings were conducted. Our evaluation showed very high correlation (r>0.95) with the gold standards across all assessed gait parameters except for cycle time (r=0.91). Similarly, the coefficient of determination was high (R2>0.9) for all gait parameters except cycle time. The highest correlation was achieved for stride length and velocity (r≥0.98,R2≥0.95). Furthermore, the multi-hour recordings did not show the systematic drift of measurements over time. Overall, the unobtrusive gait measurement system allows for contactless, highly accurate long- and short-term assessments of gait in home-like environments.

Theta burst stimulation in neglect after stroke: functional outcome and response variability origins.

Spatial neglect is a strong and negative predictor of general functional outcome after stroke, and its therapy remains a challenge. Whereas inhibitory non-invasive brain stimulation over the contralesional, intact hemisphere has generally been shown to ameliorate neglect on a group level, a conspicuous variability of the effects at the individual level is typically observed. We aimed to assess the characteristics and determinants of the effects of inhibitory non-invasive brain stimulation in neglect, identifying which patients would respond to this therapeutic approach and which not. To this end, we prospectively included 60 patients with a subacute right-hemispheric stroke. In 30 patients with spatial neglect, continuous theta burst stimulation (cTBS) was applied over the left posterior parietal cortex in a randomized clinical trial, either in eight or 16 trains, or as sham stimulation. Thirty patients without neglect served as a control group. Neglect severity was measured with a neuropsychological test battery and the Catherine Bergego Scale, at admission to and at discharge from inpatient neurorehabilitation, as well as at 3 months follow-up. General functional outcome was assessed by means of the Functional Independence Measure and the Lucerne ICF-based Multidisciplinary Observation Scale. The impact of clinical and demographic factors was evaluated, and the influence of lesion location and extension was assessed by means of voxel-based lesion-symptom mapping. On a group level, both cTBS protocols (i.e. eight and 16 trains) significantly reduced neglect severity in both the Catherine Bergego Scale and the neuropsychological tests, at discharge and 3 months later. Furthermore, cTBS significantly improved general functional outcome. On an individual level, hierarchical cluster and voxel-based lesion-symptom mapping analyses revealed that the variability in the responses to cTBS is determined by the integrity of interhemispheric connections within the corpus callosum, in particular parieto-parietal connections. In cTBS responders, in whom neglect and general functional outcome were significantly improved, the corpus callosum was intact, whereas this was not the case in cTBS non-responders. Moreover, analyses based on the proportional recovery rule and the Maugeri predictive stroke recovery model showed that the recovery of neglect and of the activities of daily living was accelerated only in cTBS responders. Furthermore, the level of activities of daily living recovery of these neglect patients was brought close to the one of right-hemispheric control patients without neglect. Hence, in neglect patients with intact interhemispheric connectivity, cTBS over the contralesional posterior parietal cortex significantly improves and accelerates neglect recovery and, associated with it, general functional outcome.

Re-fixation and perseveration patterns in neglect patients during free visual exploration.

The literature suggests that neglect patients not only show impairments in directing attention toward the left, contralesional space, but also present with perseverative behavior. Moreover, previous studies described re-fixations during visual search tasks, and interpreted this finding as an impairment of spatial working memory. The aim of the present study was to study re-fixations and perseverations (i.e., recurrent re-fixations to same locations) during free visual exploration, a task with high ecological validity. We hypothesized that: (1) neglect patient would perform re-fixations more frequently than healthy controls within the right hemispace; and, (2) the re-fixation behavior of neglect patients would be characterized by perseverative fixations. To test these hypotheses, we assessed 22 neglect patients and 23 healthy controls, measuring their eye movements during free exploration of naturalistic pictures. The results showed that neglect patients tend to re-fixate locations within the ipsilesional hemispace when they freely explore naturalistic pictures. Importantly, the saliency of discrete locations within the pictures has a stronger influence on fixation behavior within the contralesional than within the ipsilesional hemispace in neglect patients. Finally, the results indicated that, for re-fixations, saliency plays a more important role within the contralesional than the ipsilesional hemispace. Moreover, we found evidence that re-fixation behavior of neglect patients is characterized by frequent recurrent re-fixations back to the same spatial locations which may be interpreted as perseverations. Hence, with the present study, we could better elucidate the mechanism leading to re-fixations and perseverative behavior during free visual exploration in neglect patients.

Optimization and Technical Validation of the AIDE-MOI Fall Detection Algorithm in a Real-Life Setting with Older Adults.

Falls are the primary contributors of accidents in elderly people. An important factor of fall severity is the amount of time that people lie on the ground. To minimize consequences through a short reaction time, the motion sensor "AIDE-MOI" was developed. "AIDE-MOI" senses acceleration data and analyzes if an event is a fall. The threshold-based fall detection algorithm was developed using motion data of young subjects collected in a lab setup. The aim of this study was to improve and validate the existing fall detection algorithm. In the two-phase study, twenty subjects (age 86.25 ± 6.66 years) with a high risk of fall (Morse > 65 points) were recruited to record motion data in real-time using the AIDE-MOI sensor. The data collected in the first phase (59 days) was used to optimize the existing algorithm. The optimized second-generation algorithm was evaluated in a second phase (66 days). The data collected in the two phases, which recorded 31 real falls, was split-up into one-minute chunks for labelling as "fall" or "non-fall". The sensitivity and specificity of the threshold-based algorithm improved significantly from 27.3% to 80.0% and 99.9957% (0.43) to 99.9978% (0.17 false alarms per week and subject), respectively.

Long-Term Home-Monitoring Sensor Technology in Patients with Parkinson's Disease-Acceptance and Adherence.

Parkinson's disease (PD) is characterized by a highly individual disease-profile as well as fluctuating symptoms. Consequently, 24-h home monitoring in a real-world environment would be an ideal solution for precise symptom diagnostics. In recent years, small lightweight sensors which have assisted in objective, reliable analysis of motor symptoms have attracted a lot of attention. While technical advances are important, patient acceptance of such new systems is just as crucial to increase long-term adherence. So far, there has been a lack of long-term evaluations of PD-patient sensor adherence and acceptance. In a pilot study of PD patients (N = 4), adherence (wearing time) and acceptance (questionnaires) of a multi-part sensor set was evaluated over a 4-week timespan. The evaluated sensor set consisted of 3 body-worn sensors and 7 at-home installed ambient sensors. After one month of continuous monitoring, the overall system usability scale (SUS)-questionnaire score was 71.5%, with an average acceptance score of 87% for the body-worn sensors and 100% for the ambient sensors. On average, sensors were worn 15 h and 4 min per day. All patients reported strong preferences of the sensor set over manual self-reporting methods. Our results coincide with measured high adherence and acceptance rate of similar short-term studies and extend them to long-term monitoring.

[New healthcare technologies to support home care of older people]. / De nouvelles technologies au service du maintien à domicile des personnes âgées.

The ageing of the Swiss population is increasing the healthcare needs and costs. Both frailty and chronic diseases affecting older people reduce their ability to live independently. However, the vast majority of older people want to continue living at home, while having a quality of life and receiving the best healthcare services. In this context, new connected healthcare technologies can be a relevant solution to facilitate home care of older people. In this article, we present the issues related to these technologies and, more particularly, to what extent they could contribute to home care of older people and be a benefit for patients and family caregivers, but also for physicians and other healthcare professionals. Finally, the fears and risks associated with these technologies, and the importance of scientifically assessing their usefulness are discussed.

Le vieillissement de la population suisse augmente les besoins et les coûts liés à la santé. La fragilité et les maladies chroniques touchant les personnes âgées diminuent leur capacité à vivre de façon autonome. Cependant, la grande majorité d'entre eux souhaitent continuer à vivre chez eux, tout en ayant une qualité de vie et en recevant les meilleures prestations de soins. Dans ce contexte, de nouvelles technologies de santé connectée peuvent être une solution pertinente pour faciliter le maintien à domicile des personnes âgées. Nous présentons, dans cet article, les enjeux en lien avec ces technologies et, plus particulièrement, dans quelle mesure pourraient-elles contribuer au maintien à domicile des personnes âgées et être une plus-value pour les patients et les proches, mais aussi pour les médecins et les autres professionnels de santé. Enfin, les craintes et les risques associés à ces technologies et l'importance d'évaluer scientifiquement leur utilité sont discutés.

The Influence of Alertness on the Spatial Deployment of Visual Attention is Mediated by the Excitability of the Posterior Parietal Cortices.

With a reduced level of alertness, healthy individuals typically show a rightward shift when deploying visual attention in space. The impact of alertness on the neural networks governing visuospatial attention is, however, poorly understood. By using a transcranial magnetic stimulation twin-coil approach, the present study aimed at investigating the effects of an alertness manipulation on the excitability of the left and the right posterior parietal cortices (PPCs), crucial nodes of the visuospatial attentional network. Participants' visuospatial attentional deployment was assessed with a free visual exploration task and concurrent eye tracking. Their alertness level was manipulated through the time of the day, that is, by testing chronotypically defined evening types both during their circadian on- and off-peak times. The results revealed an increased excitability of the left compared with the right PPC during low alertness. On the horizontal dimension, these results were accompanied by a significant rightward shift in the center and a bilateral narrowing in the periphery of the visual exploration field, as well as a central upward shift on the vertical dimension. The findings show that the manipulation of non-spatial attentional aspects (i.e., alertness) can affect visuospatial attentional deployment and modulate the excitability of areas subtending spatial attentional control.

Validation of a purpose-built chewing gum and smartphone application to evaluate chewing efficiency.

OBJECTIVES: To validate a purpose-built two-coloured chewing gum (Hue-Check Gum® ), and to test the accuracy of a custom-built smartphone application for a colour-mixing ability test to assess chewing function. METHODS: Fully dentate participants (28D-group) and edentulous participants with implant overdentures (IOD-group) were recruited. They chewed a Hue-Check Gum® for 5, 10, 20, 30 and 50 chewing cycles, respectively. Maximum voluntary bite force (MBF) was assessed with a digital gauge. The specimens were analysed according to their colour mixture (variance of hue, VOH) with a validated software (VOH_scan) and a newly developed smartphone application (VOH_app). RESULTS: Participants segregated by dental state were significantly different regarding the number of occluding pairs of teeth, age and MBF. VOH_scan showed a negative logarithmic association with the number of chewing cycles, and VOH could be predicted from chewing cycles, MBF and gender. The clearest discrimination between the IOD and the 28D groups was observed for n = 20 chewing cycles; at this point, VOH was distinguishably different with a P-value < 0.0001. The VOH_app was a very good predictor for VOH_scan with 0.80 < pseudo-R2  < 0.83, depending on light exposure and measuring distance. There was, however, a systematic error in the accuracy of the app for inadequately chewed specimens. CONCLUSIONS: The use of the two-coloured chewing gum would provide a fast, simple and inexpensive method for the assessment of masticatory performance, which could be used in geriatric wards or in private practices without the requirement of specialised equipment or trained staff.

Spatial Neglect Predicts Upper Limb Use in the Activities of Daily Living.

BACKGROUND AND PURPOSE: Motor tests performed at stroke onset have been shown to predict the recovery of upper limb motor impairment. Less is known about upper limb recovery at the level of functional activity or of participation and how spatial neglect may influence the integration of the upper limb in the activities of daily living (ADL). Our objective was to investigate whether the initial severity of spatial neglect may predict upper limb use in ADL. METHODS: Eighty-two patients with a right-hemispheric stroke (RHS) were prospectively included in the study. They were assessed twice in the acute/subacute and in the subacute/chronic phases (mean time interval of 45 days) after stroke. The Catherine Bergego Scale (CBS) was used to quantify the influence of spatial neglect on the ADL. Contralesional upper limb use in the ADL was evaluated with the Lucerne international classification of function, disability and health-based Multidisciplinary Observation Scale. Hand strength was measured using the Jamar, dexterity with the Nine Hole Peg test, and tactile perception using the stereognosis subtest of the Nottingham Sensory Assessment. Cognitive functions were assessed with the Montreal Cognitive Assessment. RESULTS: Regression analyses revealed that spatial neglect is an independent and a significant predictor of upper limb outcome. A CBS score of ≤5 at the time of admission to neurorehabilitation care was highly predictive for good upper limb use in the ADL 45 days later. CONCLUSIONS: This study demonstrates that spatial neglect severity, as observed in the ADL, is a significant and an independent predictor of upper limb outcome. Neglect therapy is thus needed to further improve contralesional upper limb use in the ADL in RHS patients.

Theta burst stimulation over premotor cortex in Parkinson's disease: an explorative study on manual dexterity.

Dorsal pre-motor cortex (PMd) is thought to play a role in fine motor control. The aim of the present study was to investigate whether inhibitory or excitatory stimulation of PMd would have an impact on manual dexterity in Parkinson's disease (PD). Fifteen patients with PD participated in this study. High resolution structural MRI was used for neuro-navigated TBS. Participants were targeted with one train of TBS in three experimental sessions: sham stimulation over vertex, continuous TBS (cTBS) over PMd and intermittent TBS (iTBS) over PMd, respectively. Dexterity was measured by a coin rotation task (CRT), which is a valid measure to detect limb kinetic apraxia (LKA). Neither cTBS or iTBS significantly interfered with CRT. Post hoc sub-analysis in a group of PD patients (n = 5) with stronger baseline impairment, indicating LKA, revealed further deterioration of dexterous performance for the cTBS condition (p = 0.04). This sham controlled pilot study demonstrates that TBS over PMd does not significantly interfere with dexterity in PD. However, patients with dexterous impairment qualifying for LKA may be more susceptible to TBS.

Visual Hallucinations in Eye Disease and Lewy Body Disease.

OBJECTIVES: Visual hallucinations (VH) most commonly occur in eye disease (ED), Parkinson disease (PD), and Lewy body dementia (LBD). The phenomenology of VH is likely to carry important information about the brain areas within the visual system generating them. METHODS: Data from five controlled cross-sectional VH studies (164 controls, 135 ED, 156 PD, 79 [PDD 48 + DLB 31] LBD) were combined and analyzed. The prevalence, phenomenology, frequency, duration, and contents of VH were compared across diseases and sex. RESULTS: Simple VH were most common in ED patients (ED 65% versus LBD 22% versus PD 9%, χ(2) = 31.43, df = 2, p < 0.001), whereas complex VH were more common in LBD (LBD 76% versus ED 38%, versus PD 28%, χ(2) = 96.80, df = 2, p < 0.001). The phenomenology of complex VH was different across diseases and sex. ED patients reported more "flowers" (ED 21% versus LBD 6% versus PD 0%, χ(2) = 10.04, df = 2, p = 0.005) and "body parts" (ED 40% versus LBD 17% versus PD 13%, χ(2) = 11.14, df = 2, p = 0.004); in contrast, LBD patients reported "people" (LBD 85% versus ED 67% versus PD 63%, χ(2) = 6.20, df = 2, p = 0.045) and "animals/insects" (LBD 50% versus PD 42% versus ED 21%, χ(2) = 9.76, df = 2, p = 0.008). Men reported more "machines" (13% versus 2%, χ(2) = 6.94, df = 1, p = 0.008), whereas women reported more "family members/children" (48% versus 29%, χ(2) = 5.10, df = 1, p = 0.024). CONCLUSIONS: The phenomenology of VH is likely related to disease-specific dysfunctions within the visual system and to past, personal experiences.

Test-retest reliability and four-week changes in cardiopulmonary fitness in stroke patients: evaluation using a robotics-assisted tilt table.

BACKGROUND: Exercise testing devices for evaluating cardiopulmonary fitness in patients with severe disability after stroke are lacking, but we have adapted a robotics-assisted tilt table (RATT) for cardiopulmonary exercise testing (CPET). Using the RATT in a sample of patients after stroke, this study aimed to investigate test-retest reliability and repeatability of CPET and to prospectively investigate changes in cardiopulmonary outcomes over a period of four weeks. METHODS: Stroke patients with all degrees of disability underwent 3 separate CPET sessions: 2 tests at baseline (TB1 and TB2) and 1 test at follow up (TF). TB1 and TB2 were at least 24 h apart. TB2 and TF were 4 weeks apart. A RATT equipped with force sensors in the thigh cuffs, a work rate estimation algorithm and a real-time visual feedback system was used to guide the patients' exercise work rate during CPET. Test-retest reliability and repeatability of CPET variables were analysed using paired t-tests, the intraclass correlation coefficient (ICC), the coefficient of variation (CoV), and Bland and Altman limits of agreement. Changes in cardiopulmonary fitness during four weeks were analysed using paired t-tests. RESULTS: Seventeen sub-acute and chronic stroke patients (age 62.7 ± 10.4 years [mean ± SD]; 8 females) completed the test sessions. The median time post stroke was 350 days. There were 4 severely disabled, 1 moderately disabled and 12 mildly disabled patients. For test-retest, there were no statistically significant differences between TB1 and TB2 for most CPET variables. Peak oxygen uptake, peak heart rate, peak work rate and oxygen uptake at the ventilatory anaerobic threshold (VAT) and respiratory compensation point (RCP) showed good to excellent test-retest reliability (ICC 0.65-0.94). For all CPET variables, CoV was 4.1-14.5 %. The mean difference was close to zero in most of the CPET variables. There were no significant changes in most cardiopulmonary performance parameters during the 4-week period (TB2 vs TF). CONCLUSIONS: These findings provide the first evidence of test-retest reliability and repeatability of the principal CPET variables using the novel RATT system and testing methodology, and high success rates in identification of VAT and RCP: good to excellent test-retest reliability and repeatability were found for all submaximal and maximal CPET variables. Reliability and repeatability of the main CPET parameters in stroke patients on the RATT were comparable to previous findings in stroke patients using standard exercise testing devices. The RATT has potential to be used as an alternative exercise testing device in patients who have limitations for use of standard exercise testing devices.

Patient and Informant Views on Visual Hallucinations in Parkinson Disease.

OBJECTIVE: Visual hallucinations (VHs) are a very personal experience, and it is not clear whether information about them is best provided by informants or patients. Some patients may not share their hallucinatory experiences with caregivers to avoid distress or for fear of being labeled insane, and others do not have informants at all, which limits the use of informant-based questionnaires. The aim of this study was to compare patient and caregiver views about VHs in Parkinson disease (PD), using the North-East Visual Hallucinations Interview (NEVHI). METHODS: Fifty-nine PD patient-informant pairs were included. PD patients and informants were interviewed separately about VHs using the NEVHI. Informants were additionally interviewed using the four-item version of the Neuropsychiatric Inventory. Inter-reliability and concurrent validity of the different measures were compared. RESULTS: VHs were more commonly reported by patients than informants. The inter-rater agreement between NEVHI-patient and NEVHI-informant was moderate for complex VHs (Cohen's kappa = 0.44; 95% confidence interval [CI]: 0.13-0.75; t = 3.43, df = 58, p = 0.001) and feeling of presence (Cohen's kappa = 0.35; 95% CI: 0.00-0.70; t = 2.75, df = 58, p = 0.006), but agreement was poor for illusions (Cohen's kappa = 0.25; 95% CI: -0.07-0.57; t = 2.36, df = 58, p = 0.018) and passage hallucinations (Cohen's kappa = 0.16; 95% CI: -0.04-0.36; t = 2.26, df = 58, p = 0.024). CONCLUSION: When assessing VHs in PD patients, it is best to rely on patient information, because not all patients share the details of their hallucinations with their caregivers.