A short add-on sleep intervention in the rehabilitation of individuals with acquired brain injury: A randomized controlled trial

BACKGROUND

Sleep disturbances are common after acquired brain injury (ABI) and have a negative impact on functioning.

OBJECTIVE

This study examines whether a short add-on therapy for sleep disturbances in individuals with ABI is effective in addition to rehabilitation treatment as usual.

METHODS

In the randomized-controlled study, 54 adults with ABI and self-reported sleep disturbances receiving outpatient rehabilitation services were randomized in two groups: one receiving a sleep intervention (based on cognitive behavioural therapy for insomnia (CBT-I)) in addition to their rehabilitation treatment (CBT-I + TAU group) and one receiving treatment as usual (TAU). The primary outcome was sleep quality, measured with the Pittsburgh Sleep Quality Index (PSQI). Secondary outcomes included measures of anxiety, depression, fatigue and dysfunctional beliefs and attitudes about sleep.

RESULTS

The short add-on sleep therapy resulted in improvements in sleep quality in the CBT-I + TAU group as compared to the TAU group (ES = 0.924). Furthermore, the CBT-I + TAU group reported less dysfunctional beliefs and attitudes about sleep and were better able to cope with fatigue compared to the TAU group.

CONCLUSIONS

The application of this short add-on sleep intervention could be implemented in neuropsychological rehabilitation settings.

Long-term cognitive performance and its relation to anti-inflammatory therapy in a cohort of survivors of severe COVID-19

Background and objectives

Long-term cognitive performance data in former critically ill COVID-19 patients are sparse. Current evidence suggests that cognitive decline is related to neuroinflammation, which might be attenuated by COVID-19 related anti-inflammatory therapies. The objective of this prospective cohort study was to study long term cognitive outcomes following severe COVID-19 and the relation to anti-inflammatory therapies.

Methods

Prospective observational cohort of patients that survived an intensive care unit (ICU) admission due to severe COVID-19. Six months after hospital discharge, we extensively assessed both objective cognitive functioning and subjective cognitive complaints. Furthermore, patients were stratified in cohorts according to their anti-inflammatory treatment (i.e. no immunomodulatory therapy, dexamethasone, or both dexamethasone and interleukin-6 receptor antagonist tocilizumab).

Results

96 patients were included (March 2020–June 2021, median [IQR] age 61 [55–69] years). 91% received invasive mechanical ventilation, and mean ± SD severity-of-disease APACHE–II–score at admission was 15.8 ± 4.1. After 6.5 ± 1.3 months, 27% of patients scored cognitively impaired. Patients that did or did not develop cognitive impairments were similar in ICU-admission parameters, clinical course and delirium incidence. Patients with subjective cognitive complaints (20%) were more likely women (61% vs 26%), and had a shorter ICU stay (median [IQR] 8 [5–15] vs 18 [9–31], p = 0.002). Objective cognitive dysfunction did not correlate with subjective cognitive dysfunction. 27% of the participants received dexamethasone during intensive care admission, 44% received additional tocilizumab and 29% received neither. Overall occurrence and severity of cognitive dysfunction were not affected by anti-inflammatory therapy, although patients treated with both dexamethasone and tocilizumab had worse executive functioning scores (Trail Making Test interference) than patients without anti-inflammatory treatment (T-score 40.3 ± 13.5 vs 49.1 ± 9.3, p = 0.007).

Discussion

A relevant proportion of critically ill COVID-19 patients shows deficits in long-term cognitive functioning. Apart from more pronounced executive dysfunction, overall, anti-inflammatory therapy appeared not to affect long-term cognitive performance. Our findings provide insight in long-term cognitive outcomes in patients who survived COVID-19, that may facilitate health-care providers counseling patients and their caregivers.

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Up to a third of survivors of severe COVID-19 develops long-term cognitive impairment.

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Subjective cognitive complaints six months following severe COVID-19 do not correlate with objective cognitive impairment.

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COVID-19 related immunomodulatory therapy is not associated with the overall incidence of cognitive dysfunction.

Cognitive Function and Uremic Toxins after Kidney Transplantation: An Exploratory Study

BACKGROUND

Cognitive functions are altered in patients with CKD. However, it is suggested that cognitive functions improve after kidney transplantation, at least partially. A possible cause for this improvement could be the reduction of uremic retention solutes after transplantation. This study assessed the association between the changes in uremic toxin concentration with the changes in cognitive function in patients after kidney transplantation.

METHODS

Ten recipients of kidney transplants were compared with 18 controls (nine patients on hemodialysis, and nine patients with CKD stage 4 or 5 [eGFR <30 ml/min per 1.73 m²] who were not on dialysis). An extensive neuropsychological assessment, covering the five major cognitive domains (i.e., memory, attention and concentration, information processing speed, abstract reasoning, and executive function), was done before transplantation, at 1 week post-transplant, and 3 months after transplantation. Similarly, assessments of the 18 matched, control patients were performed longitudinally over a period of 3-5 months. Concentrations of 16 uremic retention solutes (indoxyl glucuronide, p-cresyl glucuronide, phenylglucuronide, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, indoxyl sulfate, p-cresyl sulfate, hippuric acid, phenyl sulfate, kynurenine, tryptophan, kynurenic acid, tyrosine, indole-3-acetic acid, phenylalanine, trimethylamine N-oxide, and phenylacetylglutamine) were measured in serum samples collected at the time of the neuropsychological assessments.

RESULTS

A significant improvement in cognitive function was only found in the processing-speed domain, and this was observed in both patients who received a transplant and patients with CKD. No significant differences between patients who received a transplant and the control groups were seen in the other cognitive domains. As expected, the serum concentration of most uremic toxins decreased significantly within 1 week after kidney transplantation.

CONCLUSIONS

There was no significant improvement in cognitive function that could be specifically related to kidney transplantation in the first 3 months after the procedure. These data do not support the notion that uremic toxins exert an immediate effect on cognitive function.

Information Recall in Pre-Operative Consultation for Glioma Surgery Using Actual Size Three-Dimensional Models

Three-dimensional (3D) technologies are being used for patient education. For glioma, a personalized 3D model can show the patient specific tumor and eloquent areas. We aim to compare the amount of information that is understood and can be recalled after a pre-operative consult using a 3D model (physically printed or in Augmented Reality (AR)) versus two-dimensional (2D) MR images. In this explorative study, healthy individuals were eligible to participate. Sixty-one participants were enrolled and assigned to either the 2D (MRI/fMRI), 3D (physical 3D model) or AR groups. After undergoing a mock pre-operative consultation for low-grade glioma surgery, participants completed two assessments (one week apart) testing information recall using a standardized questionnaire. The 3D group obtained the highest recall scores on both assessments (Cohen’s d = 1.76 and Cohen’s d = 0.94, respectively, compared to 2D), followed by AR and 2D, respectively. Thus, real-size 3D models appear to improve information recall as compared to MR images in a pre-operative consultation for glioma cases. Future clinical studies should measure the efficacy of using real-size 3D models in actual neurosurgery patients.

Development of memory clinics in the Netherlands over the last 20 years

OBJECTIVES

Memory clinics (MCs) have been established to improve diagnosis and treatment of cognitive disorders, including dementia. The aim of this study was to determine the characteristics and working methods of MCs in the Netherlands in 2016. More insight into different working methods can be used to improve the quality of care in Dutch MCs. Additionally, the findings will be compared with earlier results to investigate the development of MCs since 1998.

METHODS

A survey was sent in 1998, 2004, 2009, and 2017 to all operational Dutch MCs with questions about organization, collaboration, patients, and diagnostic procedures.

RESULTS

From 1998 to 2016, the number of MCs increased substantially from 12 to 91. The capacity increased from 1560 patients to 24,388. In 1998, most patients received a dementia diagnosis (85%), while in 2016, half of the patients were diagnosed with milder cognitive problems. MCs are more often part of regional care chains and are better embedded within regional care organizations. Diagnostic tools, such as blood tests (97%), neuropsychological assessment (NPA) (95%), and neuroimaging (92%), were used in nearly all MCs. The number of patients in whom these tools were used differed greatly between MCs (NPA: 5%-100%, neuroimaging: 10%-100%, and CSF: 0.5%-80%). There was an increase in the use of NPA, while the use of neuroimaging, CSF, and EEG/ECG decreased by 8% to 15% since 2009.

CONCLUSIONS

Since 1998, MCs have developed substantially and outgrown the primarily research-based university settings. They are now accepted as regular care facilities for people with cognitive problems.

Implicit learning seems to come naturally for children with autism, but not for children with specific language impairment: Evidence from behavioral and ERP data

Autism spectrum disorder (ASD) and specific language impairment (SLI) are two neurodevelopmental disorders characterized by deficits in verbal and nonverbal communication skills. These skills are thought to develop largely through implicit-or automatic-learning mechanisms. The aim of the current paper was to investigate the role of implicit learning abilities in the atypical development of communication skills in ASD and SLI. In the current study, we investigated Response Times (RTs) and Event Related Potentials (ERPs) during implicit learning on a Serial Reaction Time (SRT) task in a group of typically developing (TD) children (n = 17), a group of autistic children (n = 16), and a group of children with SLI (n = 13). Findings suggest that learning in both ASD and SLI are similar to that in TD. However, electrophysiological findings suggest that autistic children seem to rely mainly on more automatic processes (as reflected by an N2b component), whereas the children with SLI seem to rely on more controlled processes (as reflected by a P3 component). The TD children appear to use a combination of both learning mechanisms. These findings suggest that clinical interventions should aim at compensating for an implicit learning deficit in children with SLI, but not in children with ASD. Future research should focus on developmental differences in implicit learning and related neural correlates in TD, ASD, and SLI. Autism Res 2018, 11: 1050-1061. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc.

LAY SUMMARY

Autism and Specific Language Impairment (SLI) are two disorders characterized by problems in social communication and language. Social communication and language are believed to be learned in an automatic way. This is called "implicit learning." We have found that implicit learning is intact in autism. However, in SLI there seems different brain activity during implicit learning. Maybe children with SLI learn differently, and maybe this different learning makes it more difficult for them to learn language.

Remote Lower White Matter Integrity Increases the Risk of Long-Term Cognitive Impairment After Ischemic Stroke in Young Adults

Background and Purpose—

Poststroke cognitive impairment occurs frequently in young patients with ischemic stroke (18 through 50 years of age). Accumulating data suggest that stroke is associated with lower white matter integrity remote from the stroke impact area, which might explain why some patients have good long-term cognitive outcome and others do not. Given the life expectancy of decades in young patients, we therefore investigated remote white matter in relation to long-term cognitive function.

Methods—

We included all consecutive first-ever ischemic stroke patients, left/right hemisphere, without recurrent stroke or transient ischemic attack during follow-up, aged 18 through 50 years, admitted to our university medical center between 1980 and 2010. One hundred seventeen patients underwent magnetic resonance imaging scanning including a T1-weighted scan, a diffusion tensor imaging scan, and completed a neuropsychological assessment. Patients were compared with a matched stroke-free control group (age, sex, and education matched). Cognitive impairment was defined as >1.5 SD below the mean cognitive index score of controls and no cognitive impairment as ≤1 SD. Tract-Based Spatial Statistics was used to assess the white matter integrity (fractional anisotropy and mean diffusivity).

Results—

About 11 years after ischemic stroke, lower remote white matter integrity was associated with a worse long-term cognitive performance. A lower remote white matter integrity, even in the contralesional hemisphere, was observed in cognitively impaired patients (n=25) compared with cognitively unimpaired patients (n=71).

Conclusions—

These findings indicate that although stroke has an acute onset, it might have long lasting effects on remote white matter integrity and thereby increases the risk of long-term cognitive impairment.

Perception of emotions in mild cognitive impairment and Alzheimer's dementia: does intensity matter?

Background

To provide a review of the literature on the perception of emotion in Alzheimer’s dementia (AD) and Mild cognitive impairment (MCI), and to evaluate if emotion intensity matters.

Methodology

A systematic literature search of PubMed database was carried out using combinations or truncated versions of the keywords “MCI”, ”Alzheimer”, “emotion recognition”, “facial emotion recognition”, “social cognition” or “emotion perception”. Twenty-eight articles were found to meet the inclusion criteria.

Results

Overall, AD patients performed worse on emotion perception than MCI patients and healthy controls. Half of the studies found an emotion-specific deficit for MCI patients on the emotions anger, sadness and fear. However, studies taking emotion intensity into account are still scarce.

Conclusions

An emotion-intensity based approach may be more sensitive to detect subtle impairments in facial emotion recognition. Future studies need to take emotion intensity into account and also consider confounding factors such as overall cognition and mood.

Diffusion tensor imaging of the hippocampus and verbal memory performance: the RUN DMC study

BACKGROUND

Cerebral small vessel disease (SVD) and hippocampal atrophy are related to verbal memory failures and may ultimately result in Alzheimer's disease. However, verbal memory failures are often present before structural changes on conventional MRI appear. Changes in microstructural integrity of the hippocampus, which cannot be detected with conventional MRI, may be the underlying pathological substrate. With diffusion tensor imaging (DTI), we investigated the relation between the microstructural integrity of the hippocampus and verbal memory performance in 503 nondemented elderly with SVD.

METHODS

The Radboud University Nijmegen Diffusion tensor and Magnetic resonance imaging Cohort study is a prospective cohort study among 503 nondemented elderly with cerebral SVD aged between 50 and 85 years. All participants underwent T1 MPRAGE, fluid-attenuated inversion recovery, DTI scanning and the Rey Auditory Verbal Learning Test. After manual segmentation of the hippocampi, we calculated the mean diffusivity (MD) and fractional anisotropy in both hippocampi. The relation between memory performance and hippocampal DTI parameters was adjusted for age, sex, education, depressive symptoms, hippocampal, and white-matter lesions volume and lacunar infarcts.

RESULTS

We found inverse relations between hippocampal MD and verbal memory performance (β = -0.22; P < 0.001), immediate recall (β = -0.22; P < 0.001), delayed recall (β = -0.20; P < 0.001), and forgetting rate (β = -0.13; P = 0.025), most pronounced in participants with a normal hippocampal volume.

CONCLUSION

Microstructural integrity of the hippocampus assessed by DTI is related to verbal memory performance in elderly with SVD, also in participants with an intact appearing hippocampus. Changes in hippocampal microstructure may be an early marker of underlying neurodegenerative disease, before macrostructural (i.e., volumetric) changes occur.

The Corsi Block-Tapping Task: standardization and normative data

This article describes a standardized administration and scoring procedure for the widely used Corsi Block-Tapping Task, designed to assess the visual memory span. This method was applied in a group of healthy participants (n = 70) and a group of patients with cerebral lesions (n = 70), that were categorized on the basis of lesion location (left or right hemisphere, bilateral or subcortical). The percentile distribution as well as cutoff points on the basis of the control data are provided. It was found that 20% of the patients perform in the borderline range on this task, and over 8% have an impaired performance ("retarded"). In addition, right hemisphere patients performed worse than left hemisphere patients. These data show that the Corsi Block-Tapping Task can be effectively used to assess visuospatial short-term memory in patients with brain damage, and is selective for the side of the lesion.

Varieties of human spatial memory: a meta-analysis on the effects of hippocampal lesions

The current meta-analysis included 27 studies on spatial-memory dysfunction in patients with hippocampal damage. Each study was classified on the basis of the task that was used, i.e., maze learning, working memory, object-location memory, or positional memory. The overall results demonstrated impairments on all spatial-memory tasks. Clear differences in effect size were found between positional memory on the one hand and maze learning, object-location memory, and working memory on the other hand. Lateralization was found only on maze learning and object-location memory. These findings clearly indicate that specific aspects of spatial memory can be affected in various degrees in patients with hippocampal lesions. Moreover, these results strongly support the notion that the hippocampus is important in the processing of metric positional information, probably in the form of an allocentric cognitive map.

Spatial memory impairment in patients after tumour resection: evidence for a double dissociation

Human spatial memory can be divided into multiple, partly separate cognitive processes. In this study, object location memory was studied using a set of tasks that assessed three different spatial memory aspects: positional memory, object location binding, and a combined process. Also, maze learning and spatial span memory were measured. Ten patients who had undergone intracranial tumour resection participated, and their individual results were compared with control data from 24 healthy subjects. Four patients showed selective spatial memory impairments; two patients were impaired at positional memory, and two other patients were impaired on object location binding and the combined process. This double dissociation provides further evidence for the notion that object location memory is not a unitary system, but consists of at least two separate mechanisms. In addition, spatial memory problems were predominantly present in the patients with lesions in either the right hemisphere or in the parietal lobe. These results are in agreement with previous findings on the involvement of the right hemisphere and the posterior parietal cortices in spatial processing.

Effects of testosterone administration on selective aspects of object-location memory in healthy young women

Previous work has indicated that object-location memory is sensitive to sex differences as well as variations in the menstrual cycle. The goal of the present study was to further examine the hormonal basis of human spatial memory by assessing the effects of a single dose of exogenous testosterone in healthy young women on three recall conditions: positional reconstruction; object-to-position-assignment; and the combined condition in which subjects both have to reconstruct the precise locations and to link the different objects to the correct places. In the latter condition, delayed recall (3 min delay) improved with testosterone. Although the effects were only small and need further substantiation, they support the idea that testosterone may have an activational effect on selective aspects of cognitive functioning.

Spatial working memory performance after high-frequency repetitive transcranial magnetic stimulation of the left and right posterior parietal cortex in humans

The effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) at the left or right posterior parietal cortex were studied using a spatial working memory task. Eight subjects were stimulated over the P3 and P4 electrode site at 115% of the motor threshold (frequency 25 Hz, trains of 200 ms) during the 1000-ms delay of the spatial working memory task, or received sham stimulation. It was found that the reaction times were slower during right-parietal rTMS than during left-parietal rTMS. No differences were found between the percentages correct responses. These results are in line with recent neuroimaging findings and data from patients with cerebral lesions, suggesting that the posterior parietal cortex is especially involved in spatial processing, and provide converging evidence for recent theories on hemispheric specialization.

Frontal-lobe involvement in spatial memory: evidence from PET, fMRI, and lesion studies

Many studies have identified the prefrontal cortex as the brain area that is critical for spatial memory, both in humans and in other primates. Other studies, however, have failed to establish this relation. Therefore, the aim of this paper was to review the literature regarding the role of the human prefrontal lobe in spatial memory. This was done by examining the evidence obtained from neuropsychological patients and from studies using brain-imaging techniques (PET and fMRI). Evidence supporting the notion that the prefrontal cortex is extensively involved in spatial working memory was found. The majority of these studies, however, suggests that frontal-lobe involvement is not related to the type of material that is being processed (e.g., spatial vs. nonspatial), but to process-specific functions, such as encoding and retrieval. Theoretically, these functions could be linked to the central executive within Baddeley's working-memory model, or to recent theories that emphasize the various processes that play a role in working memory. Also, methodological issues were discussed. Further research is needed to enhance our understanding of the precise interaction of domain-specific and general processes.

Cognitive functioning after whiplash injury: a meta-analysis

Complaints on cognitive functioning are often reported in patients suffering from whiplash syndrome, although objective neuropsychological test results do not always support these. In addition, radiological abnormalities and anatomical lesions are found only in a minority of these patients. This has led to a controversy about its existence in the literature. In this systematic review, the results of 22 neuropsychological studies on whiplash were quantitatively analyzed, focusing on working memory, attention, immediate and delayed recall, visuomotor tracking, and cognitive flexibility. Our findings suggest that a consistent overall pattern of cognitive dysfunction can be demonstrated after whiplash injury through neuropsychological testing, both compared to healthy and to asymptomatic controls. Six months after the accident, improvement is found in working memory, attention, immediate recall, and visuomotor tracking. The results are discussed in the light of recent findings on the effect of cerebral dysfunction, malingering, pain-related factors, and the role of coping strategies and posttraumatic stress on neuropsychological test performance.

Memory for object locations in Korsakoff's amnesia

Deficits in spatial context memory are an important characteristic of Korsakoff's amnesia. In memory for spatial context information, there is evidence for a functional dissociation of three separate processes: (1) binding of object information to locations (i.e. binding complex memories), (2) exact, metric processing of Euclidean co-ordinates, and (3) an integration mechanism. In the present study, these sub-mechanisms were assessed experimentally in a group of Korsakoff patients (N = 20) and compared to healthy controls (N = 20) to see whether selective deficits can be demonstrated. It was found that Korsakoff patients display deficits on all three spatial-memory conditions, which are not the primary result of deficits in visuo-spatial construction and memory for object identity. No evidence for selective impairments could be observed. These impairments can be linked to damage of diencephalic regions and perhaps the parietal cortex.

P and M channel-specific interference in the what and where pathway

It was the purpose of this experiment to study interference effects of colour or luminance peripheral flicker (in order to saturate either the parvocellular or the magnocellular stream) on object identity and spatial location memory. Colour flicker interfered with object identity recognition, whereas luminance flicker affected memory for spatial location. Moreover, overall performance was worse if coloured rather than grey-scaled objects were used in the stimulus display. There was no selective effect of coloured flicker affecting coloured objects and chromatic flicker affecting chromatic objects. These results provide strong evidence for the theoretical position that the what pathway relies heavily on information derived from the P stream and the where pathway on the M stream.

Object Relocation: a program for setting up, running, and analyzing experiments on memory for object locations

Object Relocation is a computer program for Windows 95, with which experiments on spatial memory for object locations can be designed, run, and analyzed. Because of its clear graphical user interface, no long and complex command syntax is needed. Basically, a stimulus consists of a frame that contains a chosen number of locations (i.e., the actual spatial layout) to which objects can be assigned. When the experiment is run, these stimuli are presented to the subject for a variable period of time. Subsequently (either with or without a delay), the objects are presented in a row above the frame and have to be relocated to the correct positions. Finally, the raw data can be analyzed efficiently, using various error scores, and an SPSS-ready output file can be produced. Object Relocation is a very flexible program: New objects and positions can easily be added, and various options for presentation and relocation are present.

The whiplash syndrome: a psychophysiological and neuropsychological study towards attention

Whiplash patients often have physical, psychosomatic and cognitive complaints, although clear neurological and neuropsychological signs of damage are absent. However, in some studies a functional loss of attention was found. In order to compare attentional dysfunctions in whiplash patients with age-matched controls, attention was measured neuropsychologically with the aid of the PASAT, and psychophysiologically with the aid of the prepulse inhibition paradigm. In addition, the reactivity for intense acoustic stimulation was investigated. The POMS and the SCL-90 were used to evaluate psychological and somatic signs. The results showed that whiplash patients (n=24) had lower scores on the PASAT and higher scores on the questionnaires compared to healthy controls (n=21). However, no group differences could be determined on the psychophysiological variables. Furthermore, the PASAT and prepulse inhibition data did not correlate. The lower PASAT scores indicate that whiplash patients seem to have deteriorated divided attention, but an attention deficit as measured with the prepulse inhibition paradigm is not disclosed. Finally, there were no signs of a heightened reactivity of the auditory system, which casts doubts on a presumed heightened sensitivity for sound in whiplash patients.