[Atypical clinical picture of COVID-19 in older patients]. / Atypisch beeld van COVID-19 bij oudere patiënten.

Clinical characteristics and outcomes among older patients with a SARS-CoV-2 infection differ greatly from those seen in younger patients. Here we highlight atypical presentations of this fulminant infectious disease COVID-19, based on a clinical case and a cohort of 19 patients admitted to a geriatric ward. The degree of frailty, resilience and number of co-morbidities caused COVID-19 to present as acute geriatric syndrome events such as falls, delirium and dehydration in these patients. Clinical laboratory results considered typical for COVID-19 were present less often in this frail older population. As in other countries, morbidity and mortality is most severe among frail male patients; therefore, assessment of changes suggestive of typical acute geriatric syndromes in frail older patients with chronic diseases should lead to a careful clinical examination for a SARS-CoV-2 infection. Protocols for diagnosis, and contact isolation measures, should take these atypical presentations into account.

Drug dispensings among elderly in the year before colon cancer diagnosis versus matched cancer-free controls.

WHAT IS KNOWN AND OBJECTIVE: The concomitant use of multiple drugs is common among the general population of elderly. The aim of this study was to provide an overview of which drugs are dispensed to elderly in the year before colon cancer diagnosis and to compare this with cancer-free controls. METHODS: Data from the Eindhoven Cancer Registry were linked to the PHARMO Database Network. Patients with colon cancer aged ≥70 years were included and matched with controls on gender, year of birth and postal code. Proportions of cases and controls with ≥1 dispensing of each WHO ATC-2-level drug during the total year and during each quarter of the year were calculated and differences between cases and controls tested. RESULTS AND DISCUSSION: Proportion of cases with ≥1 drug dispensing was highest for drugs for constipation (cases vs. controls 58% vs. 10%), antithrombotics (42% vs. 33%), drugs for acid-related disorders (35% vs. 22%), antibacterials (34% vs. 24%), agents acting on the renin-angiotensin system (33% vs. 27%), beta-blockers (33% vs. 23%), lipid-modifying agents (29% vs. 22%), diuretics (29% vs. 21%), psycholeptics (25% vs. 18%) and antianaemics (23% vs. 6%). The proportion of cases with ≥1 drug dispensing increased from the first to the last quarter of the year for drugs for constipation (7%-53%), drugs for acid-related disorders (16%-27%), antibacterials (12%-16%), beta-blockers (26%-28%), psycholeptics (15%-19%) and antianaemics (6%-18%). Elevated proportions of cases with ≥1 drug dispensing for several drugs are mostly related to comorbidity, although increasing proportions of cases with ≥1 drug dispensing for certain drugs during the year can be attributed to the incidence of colon cancer. WHAT IS NEW AND CONCLUSION: We have provided insight into which drugs are commonly used in the year preceding colon cancer diagnosis. This may trigger general practitioners and medical specialists to further evaluate the patient.

Fusion of visual and vestibular tilt cues in the perception of visual vertical.

We investigated the effect of visual and vestibular body-tilt cues on the subjective visual vertical (SVV) in six human observers at roll tilts of 0, 60, and 120 degrees . Subjects adjusted a small luminous test line parallel to the perceived direction of gravity, in the presence of a large peripheral visual frame line. These settings, referred to as the frame SVV, were compared with the SVV in complete darkness (dark SVV). The frame SVV was virtually identical to the dark SVV for frame lines parallel or orthogonal to the dark SVV. Away from these neutral positions, the frame induced a periodic SVV modulation, which was small in upright observers, but became quite pronounced when subjects were tilted. For upright, where the dark SVV was very accurate, the frame SVV showed errors in both directions, following a roughly symmetrical pattern. At 120 degrees tilt, where the dark SVV invariably showed tilt undercompensation (A-effect), the frame effect became asymmetrical, with a stronger tendency to improve than to worsen accuracy. We tested whether our findings could be explained by two spatial orientation models: Mittelstaedt's idiotropic model and a Bayesian scheme with a stage for the processing of visual cues. Both models show a periodic frame effect that becomes stronger with increasing body tilt and can explain why frame lines parallel or perpendicular to the dark SVV are ineffective. Based on their performance, we conclude that perception of the visual vertical is based on a centrally weighted fusion of visual, vestibular, and egocentric references.

Body-tilt and visual verticality perception during multiple cycles of roll rotation.

To assess the effects of degrading canal cues for dynamic spatial orientation in human observers, we tested how judgments about visual-line orientation in space (subjective visual vertical task, SVV) and estimates of instantaneous body tilt (subjective body-tilt task, SBT) develop in the course of three cycles of constant-velocity roll rotation. These abilities were tested across the entire tilt range in separate experiments. For comparison, we also obtained SVV data during static roll tilt. We found that as tilt increased, dynamic SVV responses became strongly biased toward the head pole of the body axis (A-effect), as if body tilt was underestimated. However, on entering the range of near-inverse tilts, SVV responses adopted a bimodal pattern, alternating between A-effects (biased toward head-pole) and E-effects (biased toward feet-pole). Apart from an onset effect, this tilt-dependent pattern of systematic SVV errors repeated itself in subsequent rotation cycles with little sign of worsening performance. Static SVV responses were qualitatively similar and consistent with previous reports but showed smaller A-effects. By contrast, dynamic SBT errors were small and unimodal, indicating that errors in visual-verticality estimates were not caused by errors in body-tilt estimation. We discuss these results in terms of predictions from a canal-otolith interaction model extended with a leaky integrator and an egocentric bias mechanism. We conclude that the egocentric-bias mechanism becomes more manifest during constant velocity roll-rotation and that perceptual errors due to incorrect disambiguation of the otolith signal are small despite the decay of canal signals.

Verticality perception during off-vertical axis rotation.

During prolonged rotation about a tilted yaw axis, often referred to as off-vertical axis rotation (OVAR), a percept of being translated along a conical path slowly emerges as the sense of rotation subsides. Recently, we found that these perceptual changes are consistent with a canal-otolith interaction model that attributes the illusory translation percept to improper interpretation of the ambiguous otolith signals. The model further predicts that the illusory translation percept must be accompanied by slowly worsening tilt underestimates. Here, we tested this prediction in six subjects by measuring the time course of the subjective visual vertical (SVV) during OVAR stimulation at three different tilt-rotation speed combinations, in complete darkness. Throughout the 2-min run, at each left-ear-down and right-ear-down position, the subject indicated whether a briefly flashed line deviated clockwise or counterclockwise from vertical to determine the SVV with an adaptive staircase procedure. Typically, SVV errors indicating tilt underestimation were already present at rotation onset and then increased exponentially to an asymptotic value, reached at about 60 s after rotation onset. The initial error in the SVV was highly correlated to the response error in a static tilt control experiment. The subsequent increase in error depended on both rotation speed and OVAR tilt angle, in a manner predicted by the canal-otolith interaction model. We conclude that verticality misjudgments during OVAR reflect a dynamic component linked to canal-otolith interaction, superimposed on a tilt-related component that is also expressed under stationary conditions.

Time course and magnitude of illusory translation perception during off-vertical axis rotation.

Human spatial orientation relies on vision, somatosensory cues, and signals from the semicircular canals and the otoliths. The canals measure rotation, whereas the otoliths are linear accelerometers, sensitive to tilt and translation. To disambiguate the otolith signal, two main hypotheses have been proposed: frequency segregation and canal-otolith interaction. So far these models were based mainly on oculomotor behavior. In this study we investigated their applicability to human self-motion perception. Six subjects were rotated in yaw about an off-vertical axis (OVAR) at various speeds and tilt angles, in darkness. During the rotation, subjects indicated at regular intervals whether a briefly presented dot moved faster or slower than their perceived self-motion. Based on such responses, we determined the time course of the self-motion percept and characterized its steady state by a psychometric function. The psychophysical results were consistent with anecdotal reports. All subjects initially sensed rotation, but then gradually developed a percept of being translated along a cone. The rotation percept could be described by a decaying exponential with a time constant of about 20 s. Translation percept magnitude typically followed a delayed increasing exponential with delays up to 50 s and a time constant of about 15 s. The asymptotic magnitude of perceived translation increased with rotation speed and tilt angle, but never exceeded 14 cm/s. These results were most consistent with predictions of the canal-otolith-interaction model, but required parameter values that differed from the original proposal. We conclude that canal-otolith interaction is an important governing principle for self-motion perception that can be deployed flexibly, dependent on stimulus conditions.

[The Beers List as an aid to prevent adverse drug reactions in elderly patients]. / De beers-lijst als hulpmiddel om ernstige geneesmiddelbijwerkingen bij ouderen te voorkomen.

Elderly patients are highly susceptible for developing adverse drug reactions (ADR) that can lead to hospitalisation or death. Most of these ADR can be prevented if doctors adjust their prescriptions. Beers et al. have developed a list of drugs that should not be prescribed to elderly patients since they are known for their association with serious ADR. In The Netherlands, 20% of elderly patients receive drugs that are in the so-called Beers list. Although the Beers list has not been adjusted to the Dutch situation, avoidance of these drugs may reduce drug-related hospital admittance. Development of an improved list of drugs that should not be prescribed to elderly patients is needed that is applicable to The Netherlands.

Effect of a program of diverse activities on disturbed behavior in three severely demented patients.

The effects of a daily program of various activities on disturbed behavior were studied prospectively in three patients with severe dementia. Prior to the study, patients had not responded to treatment with benzodiazepines and/or neuroleptics. The study consisted of three periods, each lasting for 4 weeks: i.e., baseline, intervention, and follow-up. During each period, behavior was assessed by means of observation scales: GIP, SDAS, and CGI. Psychotropic medication was held as constant as possible. During intervention, the patients took part in a program of activities, including group, musical, physical, and social activities. During baseline and follow-up, patients followed the regular ward activities. The patients showed different responses, probably related to personal interests. Possible implications for the treatment of patients with dementia, complicated by disturbed behavior, and suggestions for future research are discussed. The enthusiasm of the nursing staff dealing with these patients was a promising result.

In vivo wound healing activity of Dragon's Blood (Croton spp.), a traditional South American drug, and its constituents.

The wound healing activity of dragon'sblood (Croton spp.), in Spanish 'sangre de drago? or 'sangre de grado?, a traditional South American drug, and some of its constituents, including the alkaloid taspine (1), the dihydrobenzufuran lignan 3',4-O-dimethylcedrusin (2) and proantho-cyanidins, was evaluated in vivo on rats, and compared with the wound healing actitivy of synthetic proanthocyanidins. The beneficial effect of dragon's blood on wound healing was confirmed. Dragon's blood stimulated contraction of the wound, formation of a crust, formation of new collagen, and regeneration of the epithelial layer. 3',4-O-Dimethylcedrusin also improved wound healing in vivo by stimulating the formation of fibroblasts and collagen, but crude dragon's blood was more effective. This was due to the proanthocyanidins, present in dragon's blood, which stimulate contraction of the wound and precipitate with proteins forming a dark crust covering the wound, but which delay wound repair by a decreased formation of new fibroblasts.