The role of processing speed in post-stroke cognitive dysfunction

Why am I overwhelmed by bright lights? The behavioural mechanisms of post-stroke visual hypersensitivity

After stroke, patients can experience visual hypersensitivity, an increase in their sensitivity for visual stimuli as compared to their state prior to the stroke. Candidate behavioural mechanisms for these subjective symptoms are atypical bottom-up sensory processing and impaired selective attention, but empirical evidence is currently lacking. In the current study, we aimed to investigate the relationship between post-stroke visual hypersensitivity and sensory thresholds, sensory processing speed, and selective attention using computational modelling of behavioural data. During a whole/partial report task, participants (51 stroke patients, 76 orthopedic patients, and 77 neurotypical adults) had to correctly identify a single target letter that was presented alone (for 17-100 ms) or along a distractor (for 83ms). Performance on this task was used to estimate the sensory threshold, sensory processing speed, and selective attention abilities of each participant. In the stroke population, both on a group and individual level, there was evidence for impaired selective attention and -to a lesser extent- lower sensory thresholds in patients with post-stroke visual hypersensitivity as compared to neurotypical adults, orthopedic patients, or stroke patients without post-stroke sensory hypersensitivity. These results provide a significant advancement in our comprehension of post-stroke visual hypersensitivity and can serve as a catalyst for further investigations into the underlying mechanisms of sensory hypersensitivity after other types of acquired brain injury as well as post-injury hypersensitivity for other sensory modalities.

The impact of incident stroke on cognitive trajectories in later life

BACKGROUND

Cognitive impairment is common after stroke, and a large proportion of stroke patients will develop dementia. However, there have been few large prospective studies which have assessed cognition both prior to and after stroke. This study aims to determine the extent to which incident stroke impacts different domains of cognitive function in a longitudinal cohort of older community-dwelling individuals.

METHODS

19,114 older individuals without cardiovascular disease or major cognitive impairment were recruited and followed over a maximum 11 years. Stroke included ischaemic and haemorrhagic stroke and was adjudicated by experts. Cognitive function was assessed regularly using Modified Mini-Mental State Examination (3MS), Hopkins Verbal Learning Test-Revised (HVLT-R), Symbol Digit Modalities Test (SDMT), and Controlled Oral Word Association Test (COWAT). Linear mixed models were used to investigate the change in cognition at the time of stroke and decline in cognitive trajectories following incident stroke.

RESULTS

During a median follow-up period of 8.4 [IQR: 7.2, 9.6] years, 815 (4.3%) participants experienced a stroke. Over this time, there was a general decline observed in 3MS, HVLT-R delayed recall, and SDMT scores across participants. However, for individuals who experienced a stroke, there was a significantly greater decline across all cognitive domains immediately after the event immediately after the event (3MS: -1.03 [95%CI: -1.45, -0.60]; HVLT-R: -0.47 [-0.70, -0.24]; SDMT: -2.82 [-3.57, -2.08]; COWAT: -0.67 [-1.04, -0.29]) and a steeper long-term decline for three of these domains (3MS -0.62 [-0.88, -0.35]; COWAT: -0.30 [-0.46, -0.14]); HVLT-R: -0.12 [95%CI, -0.70, -0.24]). However individuals with stroke experienced no longer-term decline in SDMT compared to the rest of the participants.

CONCLUSIONS

These findings highlight the need for comprehensive neuropsychology assessments for ongoing monitoring of cognition following incident stroke; and potential early intervention.

VasCog Screen test: sensitive in detecting cognitive impairment in patients who had a stroke or with heart failure

INTRODUCTION

Vascular diseases, such as stroke and heart failure (HF), are associated with cognitive decline. Vascular cognitive impairment (CI) is commonly found in patients who had a stroke and with HF, ranging from mild CI to dementia. Early detection of CI is crucial for effective management and rehabilitation. This study aimed to develop the VasCog Screen test, a screening tool to detect CI in patients who had a stroke and with HF.

METHOD

427 patients who had a stroke and with HF were assessed using cognitive measures including Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and a formal neuropsychological battery. The short-MoCA was derived and combined with Symbol Digit Modalities Test (SDMT) to create the VasCog Screen. The discriminatory ability of different tests for CI was compared, establishing optimal cut-off points. Variants of short-MoCA including the SDMT were also evaluated.

RESULTS

Similar prevalence rates of CI were found in stroke and HF cohorts. The most prevalent neuropsychological impairment was visuomotor speed, followed by visual memory and visuoconstruction. More than half of the patients were found to have CI. The VasCog Screen outperformed MMSE, MoCA and short-MoCA in detecting CI. The addition of SDMT to variants of the short-MoCA increased diagnostic accuracy.

CONCLUSION

The VasCog Screen test offers a cognitive screening tool, which is sensitive to cognitive deficits characteristically found in patients who had a stroke and with HF. It was found to have good sensitivity, specificity and classification accuracy. It is easy to administer in busy clinics, enabling early detection of CI and facilitating appropriate interventions.

Insights into neuroinflammatory mechanisms of deep brain stimulation in Parkinson's disease

Parkinson's disease, a progressive neurodegenerative disorder, involves gradual degeneration of the nigrostriatal dopaminergic pathway, leading to neuronal loss within the substantia nigra pars compacta and dopamine depletion. Molecular factors, including neuroinflammation, impaired protein homeostasis, and mitochondrial dysfunction, contribute to the neuronal loss. Deep brain stimulation, a form of neuromodulation, applies electric current through stereotactically implanted electrodes, effectively managing motor symptoms in advanced Parkinson's disease patients. Deep brain stimulation exerts intricate effects on neuronal systems, encompassing alterations in neurotransmitter dynamics, microenvironment restoration, neurogenesis, synaptogenesis, and neuroprotection. Contrary to initial concerns, deep brain stimulation demonstrates antiinflammatory effects, influencing cytokine release, glial activation, and neuronal survival. This review investigates the intricacies of deep brain stimulation mechanisms, including insertional effects, histological changes, and glial responses, and sheds light on the complex interplay between electrodes, stimulation, and the brain. This exploration delves into understanding the role of neuroinflammatory pathways and the effects of deep brain stimulation in the context of Parkinson's disease, providing insights into its neuroprotective capabilities.

The effect of processing speed on verbal and visual memory of adults with a chronic acquired brain injury

OBJECTIVE

Memory problems are among the most frequently reported cognitive complaints by individuals with an acquired brain injury (ABI). Processing speed and working memory deficits are often the result of ABI. These cognitive deficits significantly impact the acquisition and retention of information necessary for memory formation. This study investigated the influence of processing speed and working memory on immediate and delayed recall for verbal and visual memory, as well as overall memory recall in adults living with a chronic ABI.

METHODS

Sixty-three participants living with a chronic ABI, who were at least one-year post-injury, were cognitively assessed with the CNS-Vital Signs (CNS-VS) computerized cognitive battery and Wechsler Test of Adult Reading.

RESULTS

The CNS-VS Processing Speed significantly predicted delayed recall for verbal memory and overall memory performance. The CNS-VS Working Memory was not a significant predictor of memory recall.

CONCLUSIONS

Processing speed deficits negatively impact memory in individuals with a chronic ABI. These findings suggest the memory recall of adults with a chronic ABI is associated with poor processing speed and poor acquisition of information. Therefore, cognitive rehabilitation that improves processing speed should be the focus for individuals with ABI to improve memory performance as well as impaired processing speed.

Processing Speed and Attentional Shift/Mental Flexibility in Patients with Stroke: A Comprehensive Review on the Trail Making Test in Stroke Studies

The Trail Making Test (TMT) is one of the most commonly administered tests in clinical and research neuropsychological settings. The two parts of the test (part A (TMT-A) and part B (TMT-B)) enable the evaluation of visuoperceptual tracking and processing speed (TMT-A), as well as divided attention, set-shifting and cognitive flexibility (TMT-B). The main cognitive processes that are assessed using TMT, i.e., processing speed, divided attention, and cognitive flexibility, are often affected in patients with stroke. Considering the wide use of TMT in research and clinical settings since its introduction in neuropsychological practice, the purpose of our review was to provide a comprehensive overview of the use of TMT in stroke patients. We present the most representative studies assessing processing speed and attentional shift/mental flexibility in stroke settings using TMT and applying scoring methods relying on conventional TMT scores (e.g., time-to-complete part A and part B), as well as derived measures (e.g., TMT-(B-A) difference score, TMT-(B/A) ratio score, errors in part A and part B). We summarize the cognitive processes commonly associated with TMT performance in stroke patients (e.g., executive functions), lesion characteristics and neuroanatomical underpinning of TMT performance post-stroke, the association between TMT performance and patients' instrumental activities of daily living, motor difficulties, speech difficulties, and mood statue, as well as their driving ability. We also highlight how TMT can serve as an objective marker of post-stroke cognitive recovery following the implementation of interventions. Our comprehensive review underscores that the TMT stands as an invaluable asset in the stroke assessment toolkit, contributing nuanced insights into diverse cognitive, functional, and emotional dimensions. As research progresses, continued exploration of the TMT potential across these domains is encouraged, fostering a deeper comprehension of post-stroke dynamics and enhancing patient-centered care across hospitals, rehabilitation centers, research institutions, and community health settings. Its integration into both research and clinical practice reaffirms TMT status as an indispensable instrument in stroke-related evaluations, enabling holistic insights that extend beyond traditional neurological assessments.

Correlating Eye-Tracking Fixation Metrics and Neuropsychological Assessment after Ischemic Stroke

Background and Objectives: Stroke survivors commonly experience cognitive deficits, which significantly impact their quality of life. Integrating modern technologies like eye tracking into cognitive assessments can provide objective and non-intrusive measurements. Materials and Methods: This study aimed to evaluate the cognitive and visual processing capabilities of stroke patients using eye-tracking metrics and psychological evaluations. A cohort of 84 ischemic stroke patients from the N-PEP-12 clinical study was selected for secondary analysis, based on the availability of eye-tracking data collected during a visual search task using an adapted Trail Making Test. Standardized cognitive assessments, including the Montreal Cognitive Assessment (MoCA) and digit span tasks, were also conducted. Results: Correlation analyses revealed some notable relationships between eye-tracking metrics and cognitive measures, such as a positive correlation between Symbol Search performance and the number of fixations. Anxiety levels were found to be positively correlated with first fixation duration, while longer first fixation durations were associated with poorer cognitive performance. However, most correlations were not statistically significant. Nonparametric ANOVA showed no significant differences in fixation metrics across the visits. Conclusions: These findings suggest a complex relationship between cognitive status, gaze fixation behavior, and psychological well-being in stroke patients. Further research with larger sample sizes and analysis of saccadic eye movements is needed to better understand these relationships and inform effective interventions for stroke rehabilitation.

Stroke damages attentional maintenance in working memory

Stroke is the main cause of acquired disability in adults, and specific deficits in working memory (WM) are among the most common cognitive consequences. In neuropsychological routine, WM is most of the time investigated in the framework of the multicomponent model (Baddeley & Hitch, 1974, The psychology of learning and motivation, 47). Using a more recent theoretical WM model, the time-based resource-sharing (TBRS) model (Barrouillet et al., 2011, Psychol. Rev., 118, 175), the aim of the present study was to investigate in young post-stroke patients to which extent attentional maintenance is impaired in WM. To address this question, we discarded other factors known to directly influence WM performance, that is processing speed and short-term memory span. We proposed to 53 post-stroke patients and to 63 healthy controls a complex span paradigm in which participants were asked to alternate between the memorization of a series of images and a concurrent parity judgement task of a series of digits. To investigate the attentional maintenance processes, we manipulated the cognitive load (CL) of the concurrent task. CL effect is typically interpreted as the involvement of attentional maintenance processes. The task was adapted to each participant according to their processing speed and memory span. As expected, the results showed higher recall performance in healthy controls compared with post-stroke patients. Consistent with the literature, we also observed higher performance when the CL was low compared with high. However, the improvement in recall at low CL was smaller for post-stroke patients compared with controls, suggesting that post-stroke WM deficit could be in part due to a deficit of the attentional maintenance processes.

Effect of RehaCom cognitive rehabilitation software on working memory and processing speed in chronic ischemic stroke patients

Stroke survivors need assistance to overcome cognitive impairments. Working memory (WM) and processing speed (PS) as two critical cognitive functions are disrupted by stroke. The goal of this study was to investigate the effect of RehaCom rehabilitation software on WM and PS in participants with chronic ischemic stroke with hemiplegia (right/left side). Participants were selected among stroke patients who were referred to our special rehabilitation clinic. Fifty participants were assigned to control (n = 25) and experimental (n = 25) groups. The results of the experimental group were compared with the control group before and after the treatment with RehaCom (ten 45-min sessions across five weeks, two sessions per week). The results showed a significant improvement in WM and PS in the experimental group in comparison with the control group after a 5-week training with RehaCom. In conclusion, our findings indicate that treatment with RehaCom software improves WM and PS in chronic ischemic stroke participants with hemiplegia. The exact mechanism of RehaCom is largely unknown and further studies are needed, but its effects on the function of brain regions involved in modulating cognitive functions such as the prefrontal cortex, cingulate cortex, and parietal cortex may be mechanisms of interest.

Subjective and objective assessments are associated for physical function but not cognitive function in community-dwelling stroke survivors

PURPOSE

To investigate the relation between subjectively and objectively assessed cognitive and physical functioning among community-dwelling stroke survivors, and to examine the association of stroke severity with subjectively and objectively assessed cognitive and physical impairments.

MATERIALS AND METHODS

Secondary data analysis was conducted with 127 community-dwelling stroke survivors. For cognitive functioning, objective measures included the NIH Toolbox Cognition Battery and the Executive Function Performance Test; subjective measures included the Quality of Life in Neurological Disorders Applied Cognition. Objective and subjective physical functioning was measured by the NIH Toolbox 2-Minute Walk Test and the Patient-Reported Outcomes Measurement Information System Physical Function, respectively.

RESULTS

A positive correlation was observed between subjective and objective physical functioning, whereas the correlation between subjective and objective cognitive functioning was nonsignificant. Stroke severity was associated with objective cognitive impairment and objective and subjective physical impairment, but not subjective cognitive impairment.

CONCLUSIONS

The lack of association between objective and subjective cognitive functioning challenges the conventional assumption that perceived functioning reflects actual performance. We recommend using both objective and subjective measures to accurately identify cognitive and physical impairment following stroke.Implications for RehabilitationSubjective cognitive functioning is not associated with objective cognitive functioning, suggesting that solely relying on stroke patients' reports is inadequate and may inaccurately estimate patients' actual deficits.Both objective and subjective measures should be used to accurately identify cognitive and physical impairment following stroke.Practitioners should be cognizant of stroke patients' behavioral signs associated with underlying cognitive problems that warrant further evaluation.

Vascular Cognitive Impairment After Mild Stroke: Connectomic Insights, Neuroimaging, and Knowledge Translation

Contemporary stroke assessment protocols have a limited ability to detect vascular cognitive impairment (VCI), especially among those with subtle deficits. This lesser-involved categorization, termed mild stroke (MiS), can manifest compromised processing speed that negatively impacts cognition. From a neurorehabilitation perspective, research spanning neuroimaging, neuroinformatics, and cognitive neuroscience supports that processing speed is a valuable proxy for complex neurocognitive operations, insofar as inefficient neural network computation significantly affects daily task performance. This impact is particularly evident when high cognitive loads compromise network efficiency by challenging task speed, complexity, and duration. Screening for VCI using processing speed metrics can be more sensitive and specific. Further, they can inform rehabilitation approaches that enhance patient recovery, clarify the construct of MiS, support clinician-researcher symbiosis, and further clarify the occupational therapy role in targeting functional cognition. To this end, we review relationships between insult-derived connectome alterations and VCI, and discuss novel clinical approaches for identifying disruptions of neural networks and white matter connectivity. Furthermore, we will frame knowledge translation efforts to leverage insights from cutting-edge structural and functional connectomics research. Lastly, we highlight how occupational therapists can provide expertise as knowledge brokers acting within their established scope of practice to drive substantive clinical innovation.

Multidomain cognitive dysfunction after minor stroke suggests generalized disruption of cognitive networks

OBJECTIVE

Although small strokes typically result in "good" functional outcomes, significant cognitive impairment can occur. This longitudinal study examined a cohort of patients with minor stroke to determine the pattern of deficits, evolution over time, and factors associated with outcome.

METHODS

Patients admitted to the hospital with their first clinical minor stroke (NIH Stroke Scale [NIHSS] ≤ 10, absence of severe hemiparesis, aphasia, or neglect) were assessed at 1 month post-infarct, and a subset were followed over time (with 6- and 12-month evaluations). Composite scores at each time point were generated for global cognition, verbal memory, spatial memory, motor speed, processing speed, and executive function. Paired t-tests evaluated change in scores over time. Regression models identified factors associated with initial performance and better recovery.

RESULTS

Eighty patients were enrolled, evaluated at 1 month, and prospectively followed. The average age of the participants was 62.3 years, and mean education was 13.5 years. The average stroke volume was 6.6 cc; mean NIHSS score was 2.8. At 1 month, cognitive scores were below the normative range and > 1 standard deviation below the patient's peak ("recovery") score for every cognitive domain, strongly suggesting that they were well below patients' prestroke baselines. Forty-eight patients followed up at 6 months, and 39 at 12 months. Nearly all (98%) patients significantly improved in global cognition (averaged across domains) between 1 and 6 months. Between 6 and 12 months, recovery was variable. Higher education, occupational class, and Caucasian race were associated with higher recovery scores for most domains.

CONCLUSIONS

Cognitive impairment across multiple domains is common following minor stroke regardless of infarct location, suggesting a global process such as network dysfunction that improves over 6 months. Degree of recovery can be predicted using baseline factors.

Can subjective cognitive complaints at three months post stroke predict alteration in information processing speed during the first year?

Cognitive impairment, particularly slowing of information processing speed (IPS), is prevalent after stroke. However, the link between subjective cognitive complaints (SCC) and cognitive deficit remains unclear. This study evaluated the link between SCC at three months post stroke and deficit as well as objective alterations in IPS in the first year post stroke. Patients (N = 200) and healthy controls (N = 105) took part in the COMPlaints After Stroke study (COMPAS). SCC, IPS and depression were evaluated at 3 months, 1 and 2 years post stroke. The Reliable Change Index was used to assess change in IPS in the first year post. Approximately one out of three patients showed deficit in IPS irrespective of time post stroke, while a change in IPS (N = 117) over time was relatively uncommon. SCC at three months post stroke did not predict change in IPS between three months and one year post stroke, where depressive symptoms did show a link. Cross sectional data showed a deficit in IPS in a substantial number of stroke patients irrespective of the point in time. Longitudinal data revealed a further decline in a small subgroup in the first year post stroke, which was not predicted by SCC at three months post stroke. The findings show that, irrespective of time post stroke and even when stroke is relatively mild, impairment in IPS is prevalent, but cannot be predicted by the complaints patients express. The link with depressive symptoms needs more exploration.

Memory Trajectories Before and After First and Recurrent Strokes

BACKGROUND AND OBJECTIVES

Evidence on timing of memory change after first and recurrent strokes is limited and inconsistent. We investigated memory trajectories before and after first and recurrent strokes in 18 European countries and tested whether the country-level acute stroke care was associated with memory change after stroke.

METHODS

Data were from the Survey of Health, Ageing and Retirement in Europe (2004-2019). Incident first and recurrent strokes were identified among baseline stroke-free individuals. Within each country, each participant with incident stroke (case group) was matched with a stroke-free individual (control group) using propensity score matching. We applied multilevel segmented linear regression to quantify acute and accelerated memory changes (measured by the sum score of immediate and delayed word recall tests; 0-20 words) before and after first and recurrent strokes in both groups. Associations between stroke and memory were compared between countries with different levels of acute stroke care indicators.

RESULTS

The final analytical sample included 35,164 participants who were stroke-free at baseline (≥50 years). A total of 2,362 incident first and 341 recurrent strokes between 2004 and 2019 were identified. In case groups, mean acute decreases in memory scores were 0.48 (95% confidence interval [CI] 0.31, 0.65) and 1.14 (95% CI 0.80, 1.48) words after first and recurrent stroke, respectively, independent of a range of confounders. No such acute decreases were observed in the control group after a hypothetical nonstroke onset date. In both groups, memory declined over time but decline rates were similar (-0.07 [95% CI -0.10, -0.05] vs -0.06 [95% CI -0.08, -0.05] words per year). The mean acute decreases in memory scores after first and recurrent strokes were smaller in countries with better access to endovascular treatment.

DISCUSSION

We found acute decreases but not accelerated declines in memory after first and recurrent strokes. Improved endovascular therapy might be associated with smaller memory loss after stroke but more evidence based on individual-level data is needed. More effort should be made in early assessment and intensive prevention of stroke among the ageing population and promoting access to and delivery of acute stroke care among patients with stroke.

Current Update on the Clinical Utility of MMSE and MoCA for Stroke Patients in Asia: A Systematic Review

Objective: Primary care clinicians in Asia employed the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) to aid dementia diagnosis post-stroke. Recent studies questioned their clinical utility in stroke settings for relying on verbal abilities and education level, as well as lack of consideration for aphasia and neglect. We aimed to review the clinical utility of the MMSE and MoCA for stroke patients in Asia and provide recommendations for clinical practice. Methods: PubMed, Scopus, Web of Science, and Science Direct were searched for relevant articles. Included studies were assessed for risk of bias. RevMan 5.4 was used for data synthesis (sensitivity and specificity) and covariates were identified. Results: Among the 48 full-text articles reviewed, 11 studies were included with 3735 total subjects; of these studies, 7 (77%) were conducted in China, 3 (27%) in Singapore, and 1 (9%) in South Korea. Both the MMSE and MoCA generally showed adequate sensitivity and specificity. Education was identified as a covariate that significantly affected detection accuracy. Due to heterogeneity in cutoff scores, methodologies, and languages, it was not feasible to suggest a single cutoff score. One additional point is recommended for MoCA for patients with <6 years of education. Conclusion: Clinicians in Asia are strongly recommended to consider the education level of stroke patients when interpreting the results of the MMSE and MoCA. Further studies in other Asian countries are needed to understand their clinical value in stroke settings.

Cognitive function is an important determinant of employment amongst young ischaemic stroke survivors with good physical recovery

BACKGROUND AND PURPOSE

This cross-sectional cohort study aims at investigating young ischaemic stroke survivors with good physical recovery 7 years post-stroke in order to analyze the relation between late cognitive ability and employment.

METHODS

Consecutive ischaemic stroke survivors participating in the Sahlgrenska Academy Study on Ischemic Stroke, <55 years of age at stroke onset, and with no or minimal persisting neurological deficits corresponding to a score ≤2 on the National Institutes of Health Stroke Scale at long-term follow-up 7 years post-stroke were included. At this follow-up, the participants were assessed with respect to general cognitive function, processing speed, executive functions, cardiovascular risk factors, self-reported employment, cognitive difficulties, fatigue, depressive symptoms, anxiety and physical function.

RESULTS

Seven years post-stroke 112/142 (79%) had part-time or full-time work and 30/142 (21%) had full-time disability pension or sick leave. Compared to those with full-time disability pension or sick leave, participants with current employment demonstrated significantly better performance with respect to general cognitive function and processing speed, and significantly lower self-ratings for cognitive difficulties, physical limitations, fatigue and depressed mood. Multivariable logistic regression selected self-rated memory (odds ratio [OR] 2.61, 95% confidence interval [CI] 1.61-4.21), processing speed (OR 3.50, 95% CI 1.67-7.33) and self-rated communication skills (OR 3.46, 95% CI 1.75-6.85) as most important correlates (area under the curve 0.83-0.87) of having current employment.

CONCLUSION

This study indicates that cognitive dysfunction is an important contributor to long-term work disability amongst young stroke survivors with good physical recovery.

The Role of Processing Speed and Cognitive Control on Word Retrieval in Aging and Aphasia

Purpose When speakers retrieve words, they do so extremely quickly and accurately-both speed and accuracy of word retrieval are compromised in persons with aphasia (PWA). This study examined the contribution of two domain-general mechanisms: processing speed and cognitive control on word retrieval in PWA. Method Three groups of participants, neurologically healthy young and older adults and PWA (n = 15 in each group), performed processing speed, cognitive control, lexical decision, and word retrieval tasks on a computer. The relationship between word retrieval speed and other tasks was examined for each group. Results Both aging and aphasia resulted in slower processing speed but did not affect cognitive control. Word retrieval response time delays in PWA were eliminated when processing speed was accounted for. Word retrieval speed was predicted by individual differences in cognitive control in young and older adults and additionally by processing speed in older adults. In PWA, word retrieval speed was predicted by severity of language deficit and cognitive control. Conclusions This study shows that processing speed is compromised in aphasia and could account for their slowed response times. Individual differences in cognitive control predicted word retrieval speed in healthy adults and PWA. These findings highlight the need to include nonlinguistic cognitive mechanisms in future models of word retrieval in healthy adults and word retrieval deficits in aphasia.

Generalized neurocognitive impairment in individuals at ultra-high risk for psychosis: The possible key role of slowed processing speed

OBJECTIVE

Widespread neurocognitive impairment is well-established in individuals at ultra-high risk (UHR) for developing psychoses, but it is unknown whether slowed processing speed may underlie impairment in other neurocognitive domains, as found in schizophrenia. The study delineated domain functioning in a UHR sample and examined if neurocognitive slowing might account for deficits across domains.

METHODS

The cross-sectional study included 50 UHR individuals with no (n = 38) or minimal antipsychotic exposure (n = 12; mean lifetime dose of haloperidol equivalent = 17.56 mg; SD = 13.04) and 50 matched healthy controls. Primary analyses compared group performance across neurocognitive domains before and after covarying for processing speed. To examine the specificity of processing speed effects, post hoc analyses examined the impact of the other neurocognitive domains and intelligence as covariates.

RESULTS

UHR individuals exhibited significant impairment across all neurocognitive domains (all ps ≤ .010), with medium to large effect sizes (Cohen's ds = -0.53 to -1.12). Only processing speed used as covariate eliminated significant between-group differences in all other domains, reducing unadjusted Cohen's d values with 68% on average, whereas the other domains used as covariates averagely reduced unadjusted Cohen's d values with 20% to 48%. When covarying each of the other domains after their shared variance with speed of processing was removed, all significant between-group domain differences remained (all ps ≤ .024).

CONCLUSION

Slowed processing speed may underlie generalized neurocognitive impairment in UHR individuals and represent a potential intervention target.

The relationship between neuropsychological dispersion, processing speed and memory after electrical injury

Introduction: Previous studies of neuropsychological performance in electrical injury (EI) patients have produced evidence of deficits in various cognitive domains, but studies have yet to investigate relationships among performance in cognitive domains post-EI. This study examined whether dispersion among neuropsychological test scores was associated with injury parameters and neuropsychological performance in EI patients. Additionally, we examined whether dispersion, processing speed and/or executive abilities explain variance in episodic verbal and visual memory performance among EI patients.Method: Data from 52 post-acute EI patients undergoing outpatient evaluation with objectively-verified valid neuropsychological test performance were examined. Tests included measures of verbal and visual memory, processing speed, and executive functioning. Dispersion was calculated from executive functioning and processing speed scores.Results: Dispersion was not related to mean performance or injury characteristics, but was significantly negatively correlated with performance on a test of processing speed, suggesting that increased dispersion is associated with reduced cognitive efficiency post-EI. Delayed visual memory was related to both dispersion scores and processing speed. Stepwise regression equations predicting delayed memory determined that processing speed most significantly predicted delayed visual memory, even after controlling for immediate visual memory. No significant relationships emerged between verbal memory and non-memory neuropsychological scores.Conclusions: This is the first study to examine neuropsychological dispersion and relationships among domains of cognitive functioning in EI. Current results suggested that neuropsychological dispersion is not a marker of general functioning or severity of injury in EI patients, but may represent more specific processing speed abilities. Processing speed predicts delayed visual memory performance in EI patients, which should be considered in interpreting test scores during evaluations.

In Search for the Meaning of Illness: Content of Narrative Discourse Is Related to Cognitive Deficits in Stroke Patients

Stroke survivors undergo a thorough cognitive diagnosis that often involves administration of multiple standardized tests. However, patient’s narrative discourse can provide clinicians with additional knowledge on patient’s subjective experience of illness, attitude toward current situation, and motivation for treatment. We evaluated the methods of analyzing thematic content and story types in relationship to cognitive impairment in stroke survivors with no aphasia (including 9 left hemisphere damage – LHD patients, and 16 right hemisphere damage – RHD patients). Cognitive impairment was evaluated in comparison to a group of 25 patients with orthopaedic injury not involving the brain. Our findings primarily show that higher elaboration on own cognitive problems, physical ailments or coping strategies in LHD patients and cognitive problems, emotional issues and circumstances of illness onset in RHD patients is related to deficits in executive functions and retrieval of information from memory. Furthermore, RHD patients who use more chaos story type show lower executive functioning. However, these results did not survive the significance threshold of p < 0.05 after Bonferroni adjustment for multiple comparisons. In conclusion, this study provides preliminary evidence that stroke survivor’s narrative can constitute an additional source of clinically-relevant information regarding patient’s experience of illness and attitude toward recovery. This knowledge can aid clinicians and nurses in everyday interactions with the patients and support individualized strategy to treatment. Still, the current results need be confirmed with future studies in a larger cohort of stroke patients.

The Oxford digital multiple errands test (OxMET): Validation of a simplified computer tablet based multiple errands test

Impairments in executive functioning are common following Acquired Brain Injury, though there are few screening tools which present a time efficient and ecologically valid approach to assessing the consequences of executive impairments. We present the Oxford Digital Multiple Errands Test (OxMET), a novel and simplified computer-tablet version of a Multiple Errands Test. We recruited 124 neurologically healthy controls and 105 stroke survivors to complete the OxMET task. Normative data and internal consistency were established from the healthy control data. Convergent and divergent validation was assessed in a mixed subset of 158 participants who completed the OxMET and OCS-Plus. Test-retest reliability was examined across a mixed subset of 39 participants. Finally, we investigated the known-group discriminability of the OxMET. The OxMET demonstrated very high internal consistency, and stable group level test-retest performance as well as good convergent and divergent validity. The OxMET demonstrated high sensitivity and good specificity in overall differentiation of stroke survivors from controls. The Oxford Digital Multiple Errands Test is a brief, easy to administer tool, designed to quickly screen for potential consequences of executive impairments in a virtual environment shopping task on a computer tablet. Initial normative data and validation within a chronic stroke cohort is presented.

Prestroke Physical Activity and Poststroke Cognitive Performance

INTRODUCTION

Physical activity (PA) is associated with a lower risk of stroke and stroke mortality as well as a favorable stroke outcome. PA may also prevent general cognitive decline. Poststroke cognitive impairment is both common and disabling, and focusing on all possible preventive measures is important. Studies on the effect of PA on poststroke cognitive performance are sparse, however. We therefore aimed to examine the association between prestroke PA and poststroke cognitive performance.

METHODS

We studied the correlation between prestroke PA and poststroke cognitive performance in a prespecified analysis in The Efficacy of Citalopram Treatment in Acute Ischemic Stroke (TALOS) trial. We used the Physical Activity Scale for the Elderly (PASE) to collect information on PA during the 7-day period before stroke. PA was quantified, and patients were stratified into quartiles based on their PASE score. Cognitive performance was measured using the Symbol Digit Modalities Test (SDMT) at 1 and 6 months and the Mini-Mental State Examination (MMSE) at 6 months. The functional outcome was assessed using the modified Rankin Scale (mRS).

RESULTS

In total, 625 of 642 patients (97%) completed the PASE questionnaire. The median age was 69 (interquartile range [IQR]: 60-77), and the median PASE score was 137 (82-205). Higher prestroke PASE quartiles (2nd, 3rd, and 4th, each compared to the 1st) were independently associated with a higher SDMT score at 1 month in the both the univariable and multivariable analyses (2nd: 3.99 points, 95% confidence interval [CI]: 1.01-6.97; 3rd: 3.6, CI: 0.6-6.61; 4th: 4.1, CI: 0.95-7.24). This association remained at 6 months. PA was not statistically associated with the MMSE score or mRS.

CONCLUSION

Higher prestroke PA was associated with a better cognitive performance as measured by the SDMT at 1 and 6 months poststroke. We found no significant association between prestroke PA and functional outcome. Our results are encouraging and support further investigations of PA as a protective measure against poststroke cognitive impairment.

Competition Enhances the Effectiveness and Motivation of Attention Rehabilitation After Stroke. A Randomized Controlled Trial

Attention deficits are among the most common cognitive impairments observed after experiencing stroke. However, a very limited number of studies have investigated the effectiveness of interventions that specifically focus on the rehabilitation of attention deficits among subjects with impaired attention. Although several interventions have included the use of computerized programs to provide dynamic stimuli, real-time performance feedback, and motivating tasks, existing studies have not exploited the potential benefits of multi-user interactions. Group-based and competitive interventions have been reported to be more enjoyable and motivating, depending on individual traits, and may potentially be more demanding, which may increase their effectiveness. This study investigated the effectiveness and motivating abilities of an intervention specifically designed to address attention deficits. This intervention combined paper-and-pencil tasks and interactive, computerized, multi-touch exercises, which were administered, either non-competitively or competitively, to a group of 43 individuals with chronic stroke. The mediating effects of competitiveness were evaluated for both intervention effectiveness and motivation. Participants were randomly sorted into two groups and underwent 20 one-hour group-based sessions, during which they either worked individually or competed with peers, according to their group allocation. Participants were assessed before and after the intervention, using the Conners' Continuous Performance Test, the d2 Test of Attention, the Color Trail Test, the Digit Span Test, and the Spatial Span Test. The competitiveness and subjective experiences of the participants after the intervention were investigated with the Revised Competitiveness Index and the Intrinsic Motivation Inventory, respectively. The results showed that participants who competed demonstrated significantly greater improvements in all cognitive abilities, except for divided attention, and reported greater enjoyment than their non-competitive peers. Both groups reported comparable levels of perceived competence, pressure, and usefulness. Interestingly, the competitiveness of the participants did not alter either the effectiveness or the subjective experience of the intervention. These findings suggest that competition might enhance the effectiveness and enjoyment of rehabilitation interventions designed to address attention deficits in individuals post-stroke, regardless of their level of competitiveness and without having a negative effect on their perceived pressure and competence.

Spatial navigation ability is associated with the assessment of smoothness of driving during changing lanes in older drivers

Background

Age-related changes affect driving ability, including the smoothness of driving. This operation requires the use of both allocentric strategies (based on world-centered representations) and egocentric strategies (based on self-centered representations); however, with age, a greater preference for egocentric strategies is evident when driving. Furthermore, an age-related decline occurs in both driving ability and spatial navigation. We therefore assessed the relationship between spatial navigation and driving smoothness and tested whether a driving simulator can be used to evaluate smooth lane changes in older drivers.

Methods

A total of 34 healthy older drivers (mean age: 68.2 ± 5.4 years old) and 20 younger drivers (mean age = 20.2 ± 5.4 years old) participated in this study. The smoothness of driving was assessed using a driving simulator and spatial navigation was assessed using the Card-Placing Test-A/B. We also assessed visual perception and general intellectual function using standard neuropsychological tests.

Results

Older drivers had significantly worse spatial navigation and exhibited less smooth driving than younger drivers. Furthermore, we found a negative correlation between the smoothness of driving and spatial navigation within both groups. These results suggest that the deterioration in spatial navigation in older people may underlie the observed decrease in driving smoothness, and that spatial navigation and smooth driving deteriorate with age.

Conclusions

Considering these results, we found a significant correlation in the older group between the smoothness of vehicle movement and spatial navigation, in the smoothness of vehicle movement between the young and old groups. The smoothness values, which indices thoroughly derived from the driving simulator are indeed showing some evidence in ego/allocentric cognitions, which may change by age. The driving simulator could aid the development of intervention programs or assessment measures for drivers with a decreased function.

Normative Data for the Symbol Digit Modalities Test in Older White Australians and Americans, African-Americans, and Hispanic/Latinos

Background

Processing speed, which can be assessed using the Symbol Digit Modalities Test (SDMT), is central to many brain functions. Processing speed declines with advanced age but substantial impairments are indicative of brain injury or disease.

Objective

The purpose of this study was to provide SDMT normative data for older community-dwelling individuals in the U.S. and Australia.

Methods

The ASPREE trial recruited 19,114 relatively healthy older men and women in Australia and the U.S. from the general community. All participants were without a diagnosis of dementia and with a Modified Mini-Mental State examination score of 78 or more at enrolment. The SDMT was administered at baseline as part of a neuropsychological test battery.

Results

The median age of participants was 74 years (range 65-99), and 56% were women. The median years of education was 12. Ethno-racial differences in SDMT performance were observed and normative data were thus presented separately for 16,289 white Australians, 1,082 white Americans, 891 African-Americans, and 316 Hispanic/Latinos. There were consistent positive associations found between SDMT and education level, and negative associations between SDMT and age. Mean scores for women were consistently higher than men with the exception of Hispanic/Latinos aged ≥70 years.

Conclusion

This study provides comprehensive SDMT normative data for whites (Australian and U.S.), Hispanic/Latinos, and African-Americans, according to gender, age, and education level. These norms can be used clinically as reference standards to screen for cognitive impairments in older individuals.

The presence and prediction of lateralized inattention 7 years post-stroke

OBJECTIVE

Lateralized inattention is a typical sign of neglect and related to poor functional outcome. Knowledge of the long-term course of this phenomenon is limited. The purpose of this study was to investigate presence and predictors for signs of lateralized inattention 7 years after stroke.

METHODS

From a cohort of acute ischemic stroke patients, aged 18-69 years (n = 297), a consecutive series of 188 survivors without recurrent stroke at follow-up 7 years later were included. Within the first week after stroke onset, stroke severity was assessed according to the Scandinavian Stroke Scale. Target omissions, asymmetry of omissions, and perceptual speed according to Star- and Letter Cancellation Tests were also assessed. Presence of lateralized inattention at the 7-year follow-up was investigated with the Star- and Letter Cancellation Tests and with the neglect item in the National Institutes of Health Stroke Scale.

RESULTS

At the follow-up, 22 (11.7%) participants had lateralized inattention and the multivariable regression showed that independent significant baseline predictors were total omissions in target cancellations (P < .001) and inferior baseline performance on visual processing speed (P = .008).

CONCLUSION

About one of ten individuals exhibited signs of lateralized inattention 7 years after stroke. Baseline performance in perceptual processing speed and target omissions independently predicted presence of late signs of lateralized inattention. This is the first time processing speed is recognized as a significant predictor of lateralized inattention several years after the stroke incidence, indicating that the longitudinal course of processing speed following stroke is a critical subject for future research.

How Much Time Do People With Aphasia Need to Respond During Picture Naming? Estimating Optimal Response Time Cutoffs Using a Multinomial Ex-Gaussian Approach

Purpose Aphasia is a language disorder caused by acquired brain injury, which generally involves difficulty naming objects. Naming ability is assessed by measuring picture naming, and models of naming performance have mostly focused on accuracy and excluded valuable response time (RT) information. Previous approaches have therefore ignored the issue of processing efficiency, defined here in terms of optimal RT cutoff, that is, the shortest deadline at which individual people with aphasia produce their best possible naming accuracy performance. The goals of this study were therefore to (a) develop a novel model of aphasia picture naming that could accurately account for RT distributions across response types; (b) use this model to estimate the optimal RT cutoff for individual people with aphasia; and (c) explore the relationships between optimal RT cutoff, accuracy, naming ability, and aphasia severity. Method A total of 4,021 naming trials across 10 people with aphasia were scored for accuracy and RT onset. Data were fit using a novel ex-Gaussian multinomial RT model, which was then used to characterize individual optimal RT cutoffs. Results Overall, the model fitted the empirical data well and provided reliable individual estimates of optimal RT cutoff in picture naming. Optimal cutoffs ranged between approximately 5 and 10 s, which has important implications for assessment and treatment. There was no direct relationship between aphasia severity, naming RT, and optimal RT cutoff. Conclusion The multinomial ex-Gaussian modeling approach appears to be a promising and straightforward way to estimate optimal RT cutoffs in picture naming in aphasia. Limitations and future directions are discussed.

Slowed Information Processing Speed at Four Years Poststroke: Evidence and Predictors from a Population-Based Follow-up Study

BACKGROUND AND PURPOSE

Slowed Information Processing Speed (IPS) is a commonly reported cognitive deficit following stroke, affecting up to 50% to 70 % of stroke survivors. IPS has a major influence on poststroke cognitive dysfunction, affecting quality of life and increasing dependence on others. Few studies have examined predictors of slow IPS after stroke, and there is a paucity of data in terms of long-term prevalence. This study examined baseline predictors associated with long-term slow IPS in a population-based stroke incidence cohort, 4 years after stroke onset.

METHODS

Adults with stroke (n = 133, m = 71.1 ± 13.5 years) completed the Symbol Digit Modalities Test (SDMT) at 4 years poststroke. Baseline predictors were obtained within 2 weeks of the acute event. Multivariate regression linear and logistic models were used to identify baseline predictors (reported as OR with 95%CI) and prevalence of impaired IPS at 4-years.

RESULTS

51% of people with stroke had low scores on the SDMT as indicated by a score of -1.0 SD to -2.5 SD (ranging from low to very low respectively). There were significant associations between slow IPS at 4-years after controlling for age and education level and the following baseline factors: older age (>75 years) (OR 3.03, 95% CI .9-9.3,P = .05), previous stroke (OR 2.74, 95% CI 1.0-7.4,P = .05), high cholesterol (OR 2.72, 95% CI 1.3-5.4,p = .01), hypertension (OR 1.82, 95% CI 0.9-3.6,p = .05), and presence of coronary artery disease (OR 3.35, 95% CI 1.6-9.6,P = .01), or arrhythmia (OR 4.40, 95% CI 1.5-12.4,P = .01).

CONCLUSIONS

Even after 4-years poststroke, slowed IPS is highly prevalent, with comorbid vascular risk factors significantly contributing to persistent impaired IPS. Early identification of adults who are at higher risk of deficits in IPS is vital to targeting the timely delivery of cognitive rehabilitation interventions, improving overall outcomes.

Cerebellar fastigial nucleus is involved in post-stroke depression through direct cerebellar-hypothalamic GABAergic and glutamatergic projections

The present study aimed to investigate whether the cerebellar fastigial nucleus (FN) is involved in post-stroke depression (PSD), and to observe the effect of direct cerebellar-hypothalamic γ-aminobutyric acid (GABA)ergic and glutamatergic projections on PSD, in order to understand the mechanisms underlying the cerebellar modulation of mood and emotion. Healthy Sprague-Dawley rats were randomly divided into five groups: Sham-operated, Stroke, PSD, FN lesion, and decussation of superior cerebellar peduncle (XSCP) lesion groups. Sham surgery was performed in animals of the Sham group (n=6). The rats in the other four groups (n=6 for each group) underwent middle cerebral artery occlusion. The rats were examined twice a week in an open field test. In addition, the expression of cytokines in hippocampal tissues, and the content of glutamate and GABA in the lateral hypothalamic area (LHA) were measured. The results showed that scores corresponding to the behavioral signs of depression were decreased in the PSD, FN lesion and XSCP lesion groups. In addition, the mRNA levels of tumor necrosis factor-α, interleukin (IL)-6, and IL-1β in the hippocampus of the PSD, FN lesion and XSCP lesion groups were significantly increased. The GABA and glutamate content in the LHA were also decreased significantly in the PSD, FN lesion and XSCP lesion groups. Taken together, the findings of the present study indicated that the cerebellar FN may be involved in PSD through the direct cerebellar-hypothalamic glutamatergic and GABAergic projections.

Cerebellar Fastigial Nucleus Stimulation in a Chronic Unpredictable Mild Stress Rat Model Reduces Post-Stroke Depression by Suppressing Brain Inflammation via the microRNA-29c/TNFRSF1A Signaling Pathway

Background

We previously reported that cerebellar fastigial nucleus stimulation reduced post-stroke depression in a rat model by reducing inflammation. This study aimed to investigate the molecular inflammatory signaling pathways associated with cerebellar fastigial nucleus stimulation in an established rat model of post-stroke depression.

Material/Methods

Twenty-four Sprague-Dawley rats included a sham group (N=6), an untreated stroke group (N=6), an untreated post-stroke depression model group (PSD) (N=6), and the model group treated with cerebellar fastigial nucleus stimulation (FNS) (N=6). The rat stroke model involved occlusion of the middle cerebral artery occlusion (MCAO). Post-stroke depression model was established using chronic unpredictable mild stress treatment and was verified using an open field test. Real-time polymerase chain reaction (PCR) and Western blot compared expression levels of microRNA-29c (miR-29c), miR-676, TNFRSF1A, tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1β in cerebellar tissue. U251 human glioblastoma cells and SH-SY5Y human neuroblastoma cells were studied in vitro.

Results

Cerebellar fastigial nucleus stimulation reduced behaviors associated with depression in the rat model, upregulated the expression of miR-29c, and reduced the expression of TNFRSF1A and inflammatory cytokines, and mildly reduced neuronal apoptosis. Bioinformatics data analysis identified a regulatory relationship between miR-29c and TNFRSF1A. SH-SY5Y cells treated with a miR-29c mimic, or TNFRSF1A short interfering RNA (siRNA), identified a negative regulatory relationship between TNFRSF1A and miR-29c.

Conclusions

In a rat model, cerebellar fastigial nucleus stimulation reduced the expression of TNFRSF1A by upregulating miR-29c expression, which suppressed the expression of inflammatory cytokines, resulting in reduced severity of post-stroke depression.

Hazard perception of stroke drivers in a video-based Japanese hazard perception task

Objective: Hazard perception (HP) is the ability to identify a hazardous situation while driving. Though HP has been well studied among neurologically intact populations, little is known about the HP of neurologically impaired populations (in this study, stroke patients). The purpose of this study is, first, to investigate the HP of stroke patients and, second, to verify the effect of lesion side (right or left hemisphere) on HP, from the viewpoint of hazard types. Methods: Sixty-seven neurologically intact age-matched older drivers and 63 stroke patients with valid driver's licenses conducted a video-based Japanese HP task. Participants were asked to indicate the hazardous events in the driving scenario. These events were classified into 3 types: (1) behavioral prediction hazards (BP), which are those where the cause is visible before it becomes a hazard; (2) environmental prediction hazards (EP), which are those where the ultimate hazard may be hidden from view; and (3) dividing and focusing attention hazards (DF), which are those where there is more than one potential hazard to monitor on approach．Participants also took part in the Trail Making Test (TMT) to evaluate visual information processing speed. Results: The results showed that the number of responses was significantly fewer for stroke patients than for age-matched drivers for all hazard types (P < .001), and this difference was not affected by lesion side (P > .05). It was also found that stroke patients showed a slower response time than age-matched drivers only for BP (P < .001). The lesion side did not affect response latency (P > .05). Results of the TMT revealed that age-matched drivers completed the task significantly faster than stroke patients (P < .001) and that neither TMT-A nor TMT-B differentiated between patients with left hemisphere damage and patients with right hemisphere damage (P > .05). Conclusions: Firstly, HP in stroke patients is low compared to age-matched drivers. Secondly, even if stroke patients notice hazards, their response may be delayed in a BP situation, due to a slower visual information processing speed. Thirdly, the lesion side does not appear to affect HP.

Cognitive deficits in acute mild ischemic stroke and TIA and effects of rt-PA

Introduction

It is unknown if treatment with rt-PA in mild acute ischemic stroke (MIS) is associated with improvement in long term cognition.

Methods

Forty-five patients with suspected acute mild stroke or transient ischemic attacks with NIHSS ≤6 were enrolled in a prospective cohort. Cognitive testing was performed within 24 h of symptom onset. Follow-up assessment was performed at Day 90 on 25 patients. Prestroke baseline cognition was based on age, years of education (YrE), history of cognitive impairment, and the Fazekas score.

Results

Eighty-five percent patients with suspected MIS or TIA showed cognitive abnormalities within 24 h of onset. There was no significant difference in age, sex, Fazekas score, or YrE between rt-PA versus No-rt-PA groups (N = 8 vs. 17).Two sample t-test for change in performance in the WMS-III sub-tests (follow-up - baseline) ± SD, indicated a difference between rt-PA 0.74 ± 0.77 and no-rt-PA groups -0.02 ± 0.83 (P = 0.044). Logistic regression for predicting normal status using the mental control subtest, at follow-up showed an OR 8.96, CI 0.98-82.12 (P = 0.05) favoring the rt-PA group. Improvement in Mental Control at 90 days occurred in patients with low white matter disease compared to high white matter disease, 0.60 ± 0.46 (P = 0.048). A statistical trend was observed and suggested an improvement on SDMT and Trail Making tests, 1.43 ± 0.8 (P = 0.077).

Conclusion

Suspected MIS and TIA patients have cognitive impairment within 24 h of onset. rt-PA administration might be associated with improvement on some cognitive tests at 90 days.

What specifically contributes to disturbed non-verbal fluency in patients with bipolar disorder: Ineffective performance initiation, slowed processing or lack of the execution strategy?

The study aimed at identifying the cognitive and clinical determinants of impaired design fluency in bipolar patients, with special reference to processing speed and performance strategy. A sample of bipolar disorder patients (BD, n = 45) and matched healthy controls (HC, n = 42) underwent the assessment of figural fluency, cognitive and manual speed, cognitive effort and affective state. An electronic version of design fluency test was applied, enabling assessment of performance speed, execution strategy and spontaneous fluctuations in production efficiency. Additional clinical variables were also controlled. BD patients produced significantly less unique designs, performed slower, utilized less effective strategy, their ability to concentrate designs production in the initial phase of performance was significantly reduced compared with HC. Regression analysis revealed that in BD patients design fluency main outcome was significantly predicted by slowed creation of designs and the number of hospitalizations, while in the HC group, the main fluency result was predicted only by the executive strategy indicators. Our study showed that non-verbal fluency in BD group was determined by essentially different neuropsychological functions than in healthy controls. Obtained findings confirm that cognitive slowdown should be an important goal of cognitive remediation and pharmacological interventions in bipolar disorder.

Construct validity of the NIH Toolbox Cognition Battery in individuals with stroke

OBJECTIVE

The National Institutes of Health (NIH) Toolbox (NIHTB) for the Assessment of Behavior and Neurological Function Cognition Battery (NIHTB-CB) provides a brief assessment (approximately 30 min) of key components of cognition. This article examines construct validity to support the clinical utility of the NIHTB-CB in individuals with stroke.

RESEARCH METHOD

A total of 131 individuals with stroke (n = 71 mild stroke; n = 60 moderate/severe stroke) completed the NIHTB-CB. Univariate analyses were conducted to examine the cognitive profiles of the two different stroke groups (mild vs. moderate/severe stroke) on NIHTB-CB measures and composite scores. Pearson correlations were conducted between NIHTB-CB and established measures to examine convergent and discriminant validity. Effect sizes and clinical impairment rates for the different NIHTB-CB measures and composite scores were also examined.

RESULTS

Participants experiencing moderate to severe stroke had poorer performance than did individuals with mild stroke on several of the NIHTB cognition measures. Evidence of convergent validity was provided by moderate to strong correlations between the NIHTB measures and the corresponding standard neuropsychological test (Pearson rs ranged from 0.31 to 0.88; median = .60). Evidence of discriminant validity was provided by smaller correlations between different cognitive domains than correlations of measures within the same domain. Effect sizes for composite and subtest scores regarding stroke severity were generally moderate-to-large. In addition, 42% of the sample were exhibiting mild cognitive impairment (i.e., ≥2 low scores on fluid tests).

CONCLUSIONS

Findings provide support for the construct validity of the NIHTB-CB in individuals with stroke. (PsycINFO Database Record

Clinical Predictors of Engagement in Inpatient Rehabilitation Among Stroke Survivors With Cognitive Deficits: An Exploratory Study

OBJECTIVES

The purpose of this exploratory study was to identify clinical predictors that could distinguish clients' level of engagement in inpatient rehabilitation following stroke.

METHODS

This is a secondary analysis of pooled data from three randomized controlled trials that examined the effects of a behavioral intervention. The sample (n=208) consisted of clients with stroke who had cognitive deficits (Quick-EXIT≥3) and were admitted to inpatient rehabilitation facilities associated with a university medical center. Individuals with pre-morbid dementia, aphasia and mood disorders were excluded. The Pittsburgh Rehabilitation Participation Scale was used to measure engagement. Clinical predictors were measured using the Functional Independence Measure, National Institutes of Health Stroke Scale, Repeatable Battery for the Assessment of Neuropsychological Status, selected subtests of the Delis-Kaplan Executive Function System, Patient Health Questionnaire-9, and Chedoke McMaster Stroke Assessment. Simple logistic regression identified individual clinical predictors associated with engagement. Hierarchical logistic regression identified the strongest predictors of engagement.

RESULTS

Impairments in executive functions [mean D-KEFS, odds ratio (OR)=4.062; 95% confidence interval (CI)=.866, 19.051], impairments in visuospatial skills (RBANS Visuospatial Index Score, OR=3.940; 95% CI=1.317, 11.785), impairments in mood (Patient Health Questionnaire-9, OR=2.059, 95% CI=.953, 4.449), and male gender (OR=2.474; 95% CI=1.145, 5.374) predicted levels of engagement in inpatient rehabilitation after controlling for study intervention group, baseline stroke severity, and baseline disability.

CONCLUSIONS

Executive functions, visuospatial skills, mood, and gender distinguished individuals with high or low engagement in inpatient rehabilitation following stroke. Further studies should examine additional factors that may influence engagement (therapist-client relationship, treatment expectancy). (JINS, 2018, 24, 572-583).

The clinical utility of a 30-minute neuropsychological assessment battery in inpatient stroke rehabilitation

Cognitive assessment is an important component of inpatient stroke rehabilitation. Few studies have empirically evaluated the clinical utility of specific neuropsychological measures in this setting. We investigated the psychometric properties and clinical utility of a 30-minute neuropsychological battery developed by the National Institute of Neurologic Disorders and Stroke (NINDS) and the Canadian Stroke Network (CSN). Clinical data were analyzed from 100 individuals with mild-moderate stroke severity on an acute inpatient rehabilitation unit who completed the NINDS-CSN battery at admission. The battery comprised the Symbol-Digit Modalities Test (SDMT), Trail Making Test, Controlled Oral Word Association Test, Animal Naming, and the Hopkins Verbal Learning Test-Revised. We evaluated the battery's distribution of scores, frequency of impaired performance, internal consistency, and ability to predict rehabilitation gain and independence in cognitively-based instrumental activities of daily living (IADL) at discharge. Results indicated that the NINDS-CSN battery was sensitive to cognitive impairment, demonstrated moderately strong internal consistency, and predicted discharge IADL. The SDMT demonstrated the strongest sensitivity to impairment and predictive validity. The NINDS-CSN battery is a clinically useful assessment battery in acute inpatient stroke rehabilitation. Complex attention and processing speed performance may be most informative in predicting amount of rehabilitation gain and IADL functioning at discharge.

Computerized Cognitive Rehabilitation of Attention and Executive Function in Acquired Brain Injury: A Systematic Review

OBJECTIVE

Comprehensive review of the use of computerized treatment as a rehabilitation tool for attention and executive function in adults (aged 18 years or older) who suffered an acquired brain injury.

DESIGN

Systematic review of empirical research.

MAIN MEASURES

Two reviewers independently assessed articles using the methodological quality criteria of Cicerone et al. Data extracted included sample size, diagnosis, intervention information, treatment schedule, assessment methods, and outcome measures.

RESULTS

A literature review (PubMed, EMBASE, Ovid, Cochrane, PsychINFO, CINAHL) generated a total of 4931 publications. Twenty-eight studies using computerized cognitive interventions targeting attention and executive functions were included in this review. In 23 studies, significant improvements in attention and executive function subsequent to training were reported; in the remaining 5, promising trends were observed.

CONCLUSIONS

Preliminary evidence suggests improvements in cognitive function following computerized rehabilitation for acquired brain injury populations including traumatic brain injury and stroke. Further studies are needed to address methodological issues (eg, small sample size, inadequate control groups) and to inform development of guidelines and standardized protocols.

Compromised Motor Dexterity Confounds Processing Speed Task Outcomes in Stroke Patients

Most conventional measures of information processing speed require motor responses to facilitate performance. However, although not often addressed clinically, motor impairment, whether due to age or acquired brain injury, would be expected to confound the outcome measure of such tasks. The current study recruited 29 patients (20 stroke and 9 transient ischemic attack) with documented reduction in dexterity of the dominant hand, and 29 controls, to investigate the extent to which 3 commonly used processing speed measures with varying motor demands (a Visuo-Motor Reaction Time task, and the Wechsler Adult Intelligence Scale-IV Symbol Search and Coding subtests) may be measuring motor-related speed more so than cognitive speed. Analyses include correlations between indices of cognitive and motor speed obtained from two other tasks (Inspection Time and Pegboard task, respectively) with the three speed measures, followed by hierarchical regressions to determine the relative contribution of cognitive and motor speed indices toward task performance. Results revealed that speed outcomes on tasks with relatively high motor demands, such as Coding, were largely reflecting motor speed in individuals with reduced dominant hand dexterity. Thus, findings indicate the importance of employing measures with minimal motor requirements, especially when the assessment of speed is aimed at understanding cognitive rather than physical function.

Validation of the NIH Toolbox in Individuals with Neurologic Disorders

OBJECTIVE

Individuals with spinal cord injury (SCI), traumatic brain injury (TBI), and stroke experience a variety of neurologically related deficits across multiple domains of function. The NIH Toolbox for the Assessment of Neurological and Behavioral Function (NIHTB) examines motor, sensation, cognition, and emotional functioning. The purpose of this paper is to establish the validity of the NIHTB in individuals with neurologic conditions.

METHODS

Community-dwelling individuals with SCI (n = 209), TBI (n = 184), or stroke (n = 211) completed the NIHTB. Relative risks for impaired performance were examined relative to a matched control groups.

RESULTS

The largest group differences were observed on the Motor domain and for the Fluid Cognition measures. All groups were at increased risk for motor impairment relative to normative standards and matched controls. Fluid cognitive abilities varied across groups such that individuals with stroke and TBI performed more poorly than individuals with SCI; increased relative risks for impaired fluid cognition were seen for individuals in the stroke and TBI groups, but not for those in the SCI group. All three neurologic groups performed normally on most measures in the Sensation Battery, although TBI participants evidenced increased risk for impaired odor identification and the stroke group showed more vision difficulties. On the Emotion Battery, participants in all three groups showed comparably poor psychological well-being, social satisfaction, and self-efficacy, whereas the TBI group also evidenced slightly increased negative affect.

CONCLUSIONS

Data provide support for the validity of the NIHTB in individuals with neurologic conditions.

Development of a Tablet-based symbol digit modalities test for reliably assessing information processing speed in patients with stroke

PURPOSE

To develop a Tablet-based Symbol Digit Modalities Test (T-SDMT) and to examine the test-retest reliability and concurrent validity of the T-SDMT in patients with stroke.

METHODS

The study had two phases. In the first phase, six experts, nine college students and five outpatients participated in the development and testing of the T-SDMT. In the second phase, 52 outpatients were evaluated twice (2 weeks apart) with the T-SDMT and SDMT to examine the test-retest reliability and concurrent validity of the T-SDMT.

RESULTS

The T-SDMT was developed via expert input and college student/patient feedback. Regarding test-retest reliability, the practise effects of the T-SDMT and SDMT were both trivial (d=0.12) but significant (p≦0.015). The improvement in the T-SDMT (4.7%) was smaller than that in the SDMT (5.6%). The minimal detectable changes (MDC%) of the T-SDMT and SDMT were 6.7 (22.8%) and 10.3 (32.8%), respectively. The T-SDMT and SDMT were highly correlated with each other at the two time points (Pearson's r=0.90-0.91).

CONCLUSIONS

The T-SDMT demonstrated good concurrent validity with the SDMT. Because the T-SDMT had a smaller practise effect and less random measurement error (superior test-retest reliability), it is recommended over the SDMT for assessing information processing speed in patients with stroke. Implications for Rehabilitation The Symbol Digit Modalities Test (SDMT), a common measure of information processing speed, showed a substantial practise effect and considerable random measurement error in patients with stroke. The Tablet-based SDMT (T-SDMT) has been developed to reduce the practise effect and random measurement error of the SDMT in patients with stroke. The T-SDMT had smaller practise effect and random measurement error than the SDMT, which can provide more reliable assessments of information processing speed.