Feasibility of a Novel Geriatric Rehabilitation Program for People With COPD-induced Malnutrition and Muscle Wasting: A Qualitative Study.

Background and Purpose: Patients with COPD-induced malnutrition and muscle wasting are often frail. Consequently, traditional rehabilitation may be even counterproductive due to energy costs and there is a need for specialized rehabilitation programs, which are lacking for these patients. We developed such a program, which includes resistance training, following Nonlinear Periodized Exercise principles and physical energy management, in combination with a restriction of physical activities. The purpose of the study was to investigate the feasibility and the potential effects of this program. Methods: Patients who are eligible for the program are those with COPD gold III/IV and a fat free mass index below standard. We conducted a qualitative feasibility study and interviewed both patients and healthcare professionals (HCPs), using a deductive approach. The open interviews were qualitatively analyzed focussing on six areas of Bowens' feasibility model: acceptability, demand, implementation, practicality, limited efficacy, and integration. Results and discussions: Seven patients and seven HCPs were interviewed. For patients, key factors that helped to adhere to the program were knowledge about energy management, alternative skills to cope with COPD, and social support. They found the program beneficial. However, several patients considered a limitation of walking and ADL activities challenging. HCPs considered the program feasible and beneficial especially for those patients who accept they need a behavior change and who adhere to the program. For HCPs, key factors were the consistent approach and coaching skills of the multidisciplinary team members, and the monitoring role of the nurses. The limitation of physical activity and endurance training deviates from existing geriatric rehabilitation programs which propagate functional activity and training. Still, evidence from the current study suggests that our tailored approach for these patients might be more appropriate and also potentially effective without harm for physical function. Conclusions: Our novel, multidisciplinary rehabilitation program is considered feasible and clinically relevant by both patients and healthcare professionals. The next step is to explore its effects on muscle strength, physical functioning, and quality of life.

Nursing home residents with Huntington's disease: Heterogeneity in characteristics and functioning.

BACKGROUND: In Huntington's disease (HD), admission to a nursing home (NH) is required in advanced disease stages. To gain insight in care needs, more knowledge is needed on the functioning of this group. OBJECTIVE: Describing patient and disease characteristics, their functioning, and gender differences. METHODS: A cross-sectional descriptive design was used to collect data of 173 patients living in eight Dutch HD-specialized NHs. Data were collected on characteristics and functioning. We tested for gender differences. RESULTS: Mean age was 58.3 years and 49.7% were men. Activities of daily living and cognition varied from 46 to 49% mildly impaired to 22-23% severely impaired. Communication was severely impaired in 24%. Social functioning was low in 31% and high in 34%. A majority of patients used psychotropic medications (80.3%) and showed neuropsychiatric signs (74%). Women were on average more dependent in ADL (severely impaired 33.3% vs 12.8%), more often depressed (26.4% vs 11.6%), and prescribed antidepressant medications more often (64.4% vs 48.8%) than men. CONCLUSIONS: The population of HD patients in NHs is heterogeneous in terms of patient and disease characteristics, and functioning. As a consequence, care needs are complex leading to implications for the required expertise of staff to provide adequate care and treatment.

Impaired Awareness in People with Severe Alcohol-Related Cognitive Deficits Including Korskoff's Syndrome: A Network Analysis.

BACKGROUND: Impaired awareness of one's own functioning is highly common in people with Korsakoff's syndrome (KS). However, it is currently unclear how awareness relates to impairments in daily functioning and quality of life (QoL). METHODS: We assessed how impaired awareness relates to cognitive, behavioral, physical, and social functioning and QoL by applying a network analysis. We used cross-sectional data from 215 patients with KS or other severe alcohol-related cognitive deficits living in Dutch long-term care facilities (LTCFs). RESULTS: Apathy has the most central position in the network. Higher apathy scores relate positively to reduced cognition and to a greater decline in activities of daily living and negatively to social participation and the use of antipsychotic drugs. Impaired awareness is also a central node. It is positively related to a higher perceived QoL, reduced cognition and apathy, and negatively to social participation and length of stay in the LTCF. Mediated through apathy and social participation, impaired awareness is indirectly related to other neuropsychiatric symptoms. CONCLUSIONS: Impaired awareness is closely related to other domains of daily functioning and QoL of people with KS or other severe alcohol-related cognitive deficits living in LTCFs. Apathy plays a central role. Network analysis offers interesting insights to evaluate the interconnection of different symptoms and impairments in brain disorders such as KS.

The Disability Paradox? Trajectories of Well-Being in Older Adults With Functional Decline.

Objectives: The 'disability paradox' (DP) suggests that most older adults maintain subjective well-being (SWB) despite functional decline. However, this may depend the SWB component: positive affect (PA), negative/depressed affect (NA/DA) or life satisfaction (LS). We assessed trajectories of these components in older adults with substantial functional decline. Methods: Data originated from the Longitudinal Aging Study Amsterdam (N = 2545) observed during 1992-2008. Using latent class growth analysis, we distinguished a group with substantial functional decline and examined their SWB trajectories and individual characteristics. Results: The DP occurred more frequently for DA (Men:73%, Women:77%) and LS (Men:14%, Women:83%) than for PA (Men:26%, Women:17%). Higher perceived control (mastery) emerged as the most consistent factor associated with higher odds of the DP. Discussion: We provide a nuanced view of the DP, shifting the question from whether it exists to for which dimension of SWB and for whom it is more or less apparent.

Risk of Death in Nursing Home Residents After COVID-19 Vaccination.

OBJECTIVES: In the first months of 2021, the Dutch COVID-19 vaccination campaign was disturbed by reports of death in Norwegian nursing homes (NHs) after vaccination. Reports predominantly concerned persons >65 years of age with 1 or more comorbidities. Also, in the Netherlands adverse events were reported after COVID-19 vaccination in this vulnerable group. Yet, it was unclear whether a causal link between vaccination and death existed. Therefore, we investigated the risk of death after COVID-19 vaccination in Dutch NH residents compared with the risk of death in NH residents prior to the COVID-19 pandemic. DESIGN: Population-based longitudinal cohort study with electronic health record data. SETTING AND PARTICIPANTS: We studied Dutch NH residents from 73 NHs who received 1 or 2 COVID-19 vaccination(s) between January 13 and April 16, 2021 (n = 21,762). As a historical comparison group, we included Dutch NH residents who were registered in the same period in 2019 (n = 27,591). METHODS: Data on vaccination status, age, gender, type of care, comorbidities, and date of NH entry and (if applicable) discharge or date of death were extracted from electronic health records. Risk of death after 30 days was evaluated and compared between vaccinated residents and historical comparison residents with Kaplan-Meier and Cox regression analyses. Regression analyses were adjusted for age, gender, comorbidities, and length of stay. RESULTS: Risk of death in NH residents after one COVID-19 vaccination (regardless of whether a second vaccination was given) was decreased compared with historical comparison residents from 2019 (adjusted HR 0.77, 95% CI 0.69-0.86). The risk of death further decreased after 2 vaccinations compared with the historical comparison group (adjusted HR 0.57, 95% CI 0.50-0.64). CONCLUSIONS AND IMPLICATIONS: We found no indication that risk of death in NH residents is increased after COVID-19 vaccination. These results indicate that COVID-19 vaccination in NH residents is safe and could reduce fear and resistance toward vaccination.

Parkinson rehabilitation in nursing homes: a qualitative exploration of the experiences of patients and caregivers.

PURPOSE: Worldwide, an increasing number of people are diagnosed with atypical Parkinsonism or idiopathic Parkinson's disease (PD). Periods of acute functional decline, triggered by acute disease, are common. Rehabilitation is often necessary to restore functioning. Skilled nursing facilities (SNFs) in the Netherlands have developed evidence-based geriatric rehabilitation for Parkinson (GR-P) programs. However, data on the experiences and needs of patients and their caregivers are lacking. This study aims to address these, in order to propose recommendations for improvement. METHODS: We performed a qualitative study, using semi-structured interviews in two Dutch SNFs offering GR-P. Nine patients with PD and six informal caregivers were included. We subjected verbatim transcripts of 15 interviews to qualitative analysis. RESULTS: Data saturation was reached after 15 interviews. Three overarching themes emerged: (1) autonomy, (2) sharing information and (3) contact with others. Loss of autonomy was linked to the underlying disease and the rehabilitation environment itself. Patients and caregivers felt overwhelmed by events before and during rehabilitation, expressing a need to receive information and discuss prior experiences. They considered communication between hospitals and SNFs to be poor. Patients did not always appreciate contact with peers. Both patients and caregivers appreciated empathic healthcare personnel with a firm knowledge on PD. CONCLUSIONS: Autonomy, sharing information and contact with others are central themes for patients and caregivers during GR-P in SNFs. We recommend actively exploring these three central themes with every patient and caregiver entering a GR-P program and offering staff continuing education on PD, in order to improve care.

The Recovery After COVID-19 in Nursing Home Residents.

Introduction: Many nursing homes (NHs) are affected by COVID-19 and 30-day mortality is high. Knowledge on recovery of NH residents after COVID-19 is limited. Therefore, we investigated the trajectory in the first three months after a COVID-19 infection in NH residents. Methods: Retrospective observational cohort study of Dutch NH residents with COVID-19 between 1 September 2020 and 1 March 2021. Prevalence of COVID-19 symptoms and functioning was determined using interRAI (ADL-Hierarchy Scale (ADL-HS), Cognitive Performance Scale (CPS) and Revised Index of Social Engagement (RISE)) at four time points. Descriptive and pattern analyses were performed. Results: Eighty-six residents were included. Symptom prevalences after three months were higher than at baseline. At group level, functioning on all domains deteriorated and was followed by recovery towards baseline, except for ADL functioning. There were four trajectories; 9.3% had no deterioration. Total and partial recovery occurred in respectively 30.2% and 55.8% of the residents. In 4.7% there was no recovery. Conclusion: In 86% of NH residents surviving three months after COVID-19, occurrence of COVID-19 symptoms and deterioration in functioning was followed by recovery. COVID-19 symptoms fatigue and sleeping behaviour were significantly more prevalent, and ADL functioning was significantly lower, at three months compared to baseline.

The course of neuropsychiatric symptoms and psychotropic drug use in Dutch nursing home patients with dementia during the first wave of COVID-19: A longitudinal cohort study.

OBJECTIVE: To describe the course of neuropsychiatric symptoms in nursing home residents with dementia during the step-by-step lifting of restrictions after the first wave of the COVID-19 pandemic in the Netherlands, and to describe psychotropic drug use (PDU) throughout the whole first wave. METHODS: Longitudinal cohort study of nursing home residents with dementia. We measured neuropsychiatric symptoms using the Neuropsychiatric Inventory-Questionnaire (NPI-Q). From May to August 2020, the NPI-Q was filled in monthly. Psychotropic drug use was retrieved from the electronic prescription system, retrospectively for the months February to April and prospectively for the months May to August. RESULTS: We followed 252 residents with dementia in 19 Dutch nursing homes. Agitation was the most prevalent type of neuropsychiatric symptom at each assessment. Overall, the prevalence and severity of agitation and depression significantly decreased over time. When considering more in detail, we observed that in some residents specific neuropsychiatric symptoms resolved (resolution) while in others specific neuropsychiatric symptoms developed (incidence) during the study period. For the majority of the residents, neuropsychiatric symptoms persisted over time. Psychotropic drug use remained stable over time throughout the whole first wave of the pandemic. CONCLUSIONS: At group level, lifting the measures appeared to have beneficial effects on the prevalence and severity of agitation and depression in residents with dementia. Nevertheless, on an individual level we observed high heterogeneity in the course of neuropsychiatric symptoms over time. Despite the pressure of the pandemic and the restrictions in social contact imposed, PDU remained stable.

Clinical evaluation of single-swab sampling for rapid COVID-19 detection in outbreak settings in Dutch nursing homes.

PURPOSE: To assess whether one swab can be used to perform both the antigen-detection rapid diagnostic test (Ag-RDT) and reverse transcriptase polymerase chain reaction (RT-PCR) for COVID-19 detection during an outbreak in the nursing home (NH) setting. METHODS: The single-swab method (SSM), where the Ag-RDT is performed with the transport medium used for RT-PCR, was evaluated in three Dutch NHs and compared to the laboratory setting. We collected Ag-RDT and RT-PCR results, NH resident characteristics and symptomatology. In addition, two focus groups were held with the involved care professionals to gain insight into the feasibility of the SMM in the NH setting. RESULTS: In the NH setting, the SSM had a sensitivity of 51% and a specificity of 89% compared to RT-PCR. These were lower than in the laboratory setting (69% and 100% respectively). Yet, when stratified for cycle threshold values, the sensitivity became comparable between the settings. Symptoms occurred more frequent in the Ag-RDT+ group than Ag-RDT- group. Resident characteristics did not differ between these groups. Based on the focus groups, the SSM was feasible to perform if certain requirements, such as availability of staff, equipment and proper training, were met. However, the rapid availability of the test results were perceived as a dilemma. CONCLUSION: The advantages and disadvantages need to be considered before implementation of the SSM can be recommended in the NH setting. For the vulnerable NH residents, it is important to find the right balance between effective testing policy and the burden this imposes.

Symptom- and Prevention-Based Testing of COVID-19 in Nursing Home Residents: A Retrospective Cohort Study.

Nursing homes (NH) residents with COVID-19 can either be tested because of presence of core symptoms (S-based) or because of transmission prevention (TP-based). The investigated study sample included all NH residents who underwent SARS-CoV-2 RT-PCR testing between March 16, 2020 and May 31, 2020 (n = 380). Clinical symptoms, temperature, and oxygen saturation were extracted from medical records, 7 days before to 14 days after testing. COVID-19 was confirmed in 81 (21%) residents; 36 (44%) S-based and 45 (56%) TP-based: 45. Cycle threshold (CT) values did not differ between the groups. In the 7 days prior to the test falling (32%), somnolence (25%) and fatigue (21%) occurred in both groups. Two days before the test, we observed a stronger decrease in oxygen saturation and an increase in temperature for the S-based group compared to the T-based group that remained up to 10 days after testing. Residents within the S-based group were 2.5 times more likely to increased mortality within 30 days than residents in the TP-based group (HR, 2.56; 95% 1.3-5.2). Although, 73% of the T-based group did eventually develop core symptoms. Thus, attention to falling and daily measures of temperature and oxygen saturation can contribute to earlier detection.

Dementia and Parkinson's Disease: Risk Factors for 30-Day Mortality in Nursing Home Residents with COVID-19.

BACKGROUND: The COVID-19 pandemic has led to high mortality rates in nursing homes (NHs) in Europe. For adequate risk management and good prognostications, it is essential to identify mortality risk factors. OBJECTIVE: This study aimed to determine whether previously identified risk factors for 30-day mortality in Dutch NH residents with COVID-19 are unique to COVID-19. METHODS: In this cohort study, we included 1,294 NH residents with COVID-19 (cases) and 17,999 NH residents without COVID-19 (controls, from the pre-COVID-19 period). We used descriptive statistics and Cox proportional hazard models to compare mortality rates in residents with and without COVID-19, categorized by risk factors. RESULTS: Cases had a more than 18 times higher hazard of death within 30 days compared to controls (HR 18, 95%CI: 16-20). For residents with COVID-19, being male, having dementia, and having Parkinson's disease (PD) were all associated with a higher 30-day mortality (HR 1.8 versus 1.3 versus 1.7). Being male was also associated with a higher mortality (HR 1.7) in the control group, whereas having dementia and PD were not. COVID-19 symptomatology was very similar for residents with and without dementia or PD, except for delirium and malaise which was more frequent in residents with dementia. CONCLUSION: Dementia and PD were significant additional risk factors for mortality in Dutch NH residents with COVID-19, whereas male gender was not unique to residents with COVID-19. The frailty of PD and dementia in NH residents with COVID-19 are relevant to consider in prognostication, communication, and care planning with residents and their families.

Content or status: Frontal and posterior cortical representations of object category and upcoming task goals in working memory.

To optimize task sequences, the brain must differentiate between current and prospective goals. We previously showed that currently and prospectively relevant object representations in working memory can be dissociated within object-selective cortex. Based on other recent studies indicating that a range of brain areas may be involved in distinguishing between currently relevant and prospectively relevant information in working memory, here we conducted multivoxel pattern analyses of fMRI activity in additional posterior areas (specifically early visual cortex and the intraparietal sulcus) as well as frontal areas (specifically the frontal eye fields and lateral prefrontal cortex). We assessed whether these areas represent the memory content, the current versus prospective status of the memory, or both. On each trial, participants memorized an object drawn from three different categories. The object was the target for either a first task (currently relevant), a second task (prospectively relevant), or for neither task (irrelevant). The results revealed a division of labor across brain regions: While posterior areas preferentially coded for content (i.e., the category), frontal areas carried information about the current versus prospective relevance status of the memory, irrespective of the category. Intraparietal sulcus revealed both strong category- and status-sensitivity, consistent with its hub function of combining stimulus and priority signals. Furthermore, cross-decoding analyses revealed that while current and prospective representations were similar prior to search, they became dissimilar during search, in posterior as well as frontal areas. The findings provide further evidence for a dissociation between content and control networks in working memory.

Clinical Suspicion of COVID-19 in Nursing Home Residents: Symptoms and Mortality Risk Factors.

OBJECTIVES: To describe the symptomatology, mortality, and risk factors for mortality in a large group of Dutch nursing home (NH) residents with clinically suspected COVID-19 who were tested with a reverse transcription-polymerase chain reaction (RT-PCR) test. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: Residents of Dutch NHs with clinically suspected COVID-19 and who received RT-PCR test. METHODS: We collected data of NH residents with clinically suspected COVID-19 via electronic health records between March 18 and May 13, 2020. Registration was performed on diagnostic status [confirmed (COVID-19+)/ruled out (COVID-19-)] and symptomatology (typical and atypical symptoms). Information on mortality and risk factors for mortality were extracted from usual care data. RESULTS: In our sample of residents with clinically suspected COVID-19 (N = 4007), COVID-19 was confirmed in 1538 residents (38%). Although symptomatology overlapped between residents with COVID-19+ and COVID-19-, those with COVID-19+ were 3 times more likely to die within 30 days [hazard ratio (HR), 3.1, 95% confidence interval (CI) 2.7-3.6]. Within this group, mortality was higher for men than for women (HR 1.8, 95% CI 1.5-2.2), and we observed a higher mortality for residents with dementia, reduced kidney function, and Parkinson's disease, even when corrected for age, gender, and comorbidities. CONCLUSIONS AND IMPLICATIONS: About 40% of the residents with clinically suspected COVID-19 actually had COVID-19, based on the RT-PCR test. Despite an overlap in symptomatology, mortality rate was 3 times higher for residents with COVID-19+. This emphasizes the importance of using low-threshold testing in NH residents, which is an essential prerequisite to using limited personal protective equipment and isolation measures efficiently.

Current and future goals are represented in opposite patterns in object-selective cortex.

Adaptive behavior requires the separation of current from future goals in working memory. We used fMRI of object-selective cortex to determine the representational (dis)similarities of memory representations serving current and prospective perceptual tasks. Participants remembered an object drawn from three possible categories as the target for one of two consecutive visual search tasks. A cue indicated whether the target object should be looked for first (currently relevant), second (prospectively relevant), or if it could be forgotten (irrelevant). Prior to the first search, representations of current, prospective and irrelevant objects were similar, with strongest decoding for current representations compared to prospective (Experiment 1) and irrelevant (Experiment 2). Remarkably, during the first search, prospective representations could also be decoded, but revealed anti-correlated voxel patterns compared to currently relevant representations of the same category. We propose that the brain separates current from prospective memories within the same neuronal ensembles through opposite representational patterns.

Pupil Dilation Reflects Task Relevance Prior to Search.

When observers search for a specific target, it is assumed that they activate a representation of the task relevant object in visual working memory (VWM). This representation - often referred to as the template - guides attention towards matching visual input. In two experiments we tested whether the pupil response can be used to differentiate stimuli that match the task-relevant template from irrelevant input. Observers memorized a target color to be searched for in a multi-color visual search display, presented after a delay period. In Experiment 1, one color appeared at the start of the trial, which was then automatically the search template. In Experiments 2, two colors were presented, and a retro-cue indicated which of these was relevant for the upcoming search task. Crucially, before the search display appeared, we briefly presented one colored probe stimulus. The probe could match either the relevant-template color, the non-cued color (irrelevant), or be a new color not presented in the trial. We measured the pupil response to the probe as a signature of task relevance. Experiment 1 showed significantly smaller pupil size in response to probes matching the search template than for irrelevant colors. Experiment 2 replicated the template matching effect and allowed us to rule out that it was solely due to repetition priming. Taken together, we show that the pupil responds selectively to participants' target template prior to search.

Oculomotor measures reveal the temporal dynamics of preparing for search.

Theories of visual search assume that selection is driven by an active template representation of the target object. Earlier studies suggest that template activation occurs prior to search, but the temporal dynamics of such preactivation remain unclear. Two experiments employed microsaccades to track both general preparation (i.e., anticipation of the search task as such) and template-specific preparation (i.e., anticipation of target selection) of visual search. Participants memorized a target color (i.e., the template) for an upcoming search task. During the delay period, we presented an irrelevant rapid serial visual presentation (RSVP) of lateralized colored disks. Crucially, at different time points into the RSVP, the template color was inserted, allowing us to measure attentional biases toward the template match as a function of time. Results showed a general suppression of saccades: the closer in time to the search display, the less saccades were produced. This suppression was stronger when a template-matching color was present compared to when absent. However, when microsaccades occurred, they were biased toward the template-matching color and more so just prior to the search display. We conclude that observers adapt search template activation to the anticipated moment of search, and that microsaccades reflect general as well as target-specific preparation effects.

Subtle eye movement metrics reveal task-relevant representations prior to visual search.

Visual search is thought to be guided by an active visual working memory (VWM) representation of the task-relevant features, referred to as the search template. In three experiments using a probe technique, we investigated which eye movement metrics reveal which search template is activated prior to the search, and distinguish it from future relevant or no longer relevant VWM content. Participants memorized a target color for a subsequent search task, while being instructed to keep central fixation. Before the search display appeared, we briefly presented two task-irrelevant colored probe stimuli to the left and right from fixation, one of which could match the current target template. In all three experiments, participants made both more and larger eye movements towards the probe matching the target color. The bias was predominantly expressed in microsaccades, 100-250 ms after probe onset. Experiment 2 used a retro-cue technique to show that these metrics distinguish between relevant and dropped representations. Finally, Experiment 3 used a sequential task paradigm, and showed that the same metrics also distinguish between current and prospective search templates. Taken together, we show how subtle eye movements track task-relevant representations for selective attention prior to visual search.

Auditory and visual scene analysis: an overview.

We perceive the world as stable and composed of discrete objects even though auditory and visual inputs are often ambiguous owing to spatial and temporal occluders and changes in the conditions of observation. This raises important questions regarding where and how 'scene analysis' is performed in the brain. Recent advances from both auditory and visual research suggest that the brain does not simply process the incoming scene properties. Rather, top-down processes such as attention, expectations and prior knowledge facilitate scene perception. Thus, scene analysis is linked not only with the extraction of stimulus features and formation and selection of perceptual objects, but also with selective attention, perceptual binding and awareness. This special issue covers novel advances in scene-analysis research obtained using a combination of psychophysics, computational modelling, neuroimaging and neurophysiology, and presents new empirical and theoretical approaches. For integrative understanding of scene analysis beyond and across sensory modalities, we provide a collection of 15 articles that enable comparison and integration of recent findings in auditory and visual scene analysis.This article is part of the themed issue 'Auditory and visual scene analysis'.

NMDA Receptor Antagonist Ketamine Distorts Object Recognition by Reducing Feedback to Early Visual Cortex.

It is a well-established fact that top-down processes influence neural representations in lower-level visual areas. Electrophysiological recordings in monkeys as well as theoretical models suggest that these top-down processes depend on NMDA receptor functioning. However, this underlying neural mechanism has not been tested in humans. We used fMRI multivoxel pattern analysis to compare the neural representations of ambiguous Mooney images before and after they were recognized with their unambiguous grayscale version. Additionally, we administered ketamine, an NMDA receptor antagonist, to interfere with this process. Our results demonstrate that after recognition, the pattern of brain activation elicited by a Mooney image is more similar to that of its easily recognizable grayscale version than to the pattern evoked by the identical Mooney image before recognition. Moreover, recognition of Mooney images decreased mean response; however, neural representations of separate images became more dissimilar. So from the neural perspective, unrecognizable Mooney images all "look the same", whereas recognized Mooneys look different. We observed these effects in posterior fusiform part of lateral occipital cortex and in early visual cortex. Ketamine distorted these effects of recognition, but in early visual cortex only. This suggests that top-down processes from higher- to lower-level visual areas might operate via an NMDA pathway.

Pupil size tracks perceptual content and surprise.

Changes in pupil size at constant light levels reflect the activity of neuromodulatory brainstem centers that control global brain state. These endogenously driven pupil dynamics can be synchronized with cognitive acts. For example, the pupil dilates during the spontaneous switches of perception of a constant sensory input in bistable perceptual illusions. It is unknown whether this pupil dilation only indicates the occurrence of perceptual switches, or also their content. Here, we measured pupil diameter in human subjects reporting the subjective disappearance and re-appearance of a physically constant visual target surrounded by a moving pattern ('motion-induced blindness' illusion). We show that the pupil dilates during the perceptual switches in the illusion and a stimulus-evoked 'replay' of that illusion. Critically, the switch-related pupil dilation encodes perceptual content, with larger amplitude for disappearance than re-appearance. This difference in pupil response amplitude enables prediction of the type of report (disappearance vs. re-appearance) on individual switches (receiver-operating characteristic: 61%). The amplitude difference is independent of the relative durations of target-visible and target-invisible intervals and subjects' overt behavioral report of the perceptual switches. Further, we show that pupil dilation during the replay also scales with the level of surprise about the timing of switches, but there is no evidence for an interaction between the effects of surprise and perceptual content on the pupil response. Taken together, our results suggest that pupil-linked brain systems track both the content of, and surprise about, perceptual events.