Cognitive assessments for the early diagnosis of dementia after stroke

Myoelectric Pattern Recognition Performance Enhancement Using Nonlinear Features

The multichannel electrode array used for electromyogram (EMG) pattern recognition provides good performance, but it has a high cost, is computationally expensive, and is inconvenient to wear. Therefore, researchers try to use as few channels as possible while maintaining improved pattern recognition performance. However, minimizing the number of channels affects the performance due to the least separable margin among the movements possessing weak signal strengths. To meet these challenges, two time-domain features based on nonlinear scaling, the log of the mean absolute value (LMAV) and the nonlinear scaled value (NSV), are proposed. In this study, we validate the proposed features on two datasets, the existing four feature extraction methods, variable window size, and various signal-to-noise ratios (SNR). In addition, we also propose a feature extraction method where the LMAV and NSV are grouped with the existing 11 time-domain features. The proposed feature extraction method enhances accuracy, sensitivity, specificity, precision, and F1 score by 1.00%, 5.01%, 0.55%, 4.71%, and 5.06% for dataset 1, and 1.18%, 5.90%, 0.66%, 5.63%, and 6.04% for dataset 2, respectively. Therefore, the experimental results strongly suggest the proposed feature extraction method, for taking a step forward with regard to improved myoelectric pattern recognition performance.

Degree of cognitive impairment in patients with carotid stenosis in relation to cerebral ischemic lesions

Background/Aim. Carotid stenosis is a risk factor for cognitive impairment. The aim of the study was to evaluate the degree of cognitive impairment in patients with asymp-tomatic and symptomatic carotid stenosis and correlate it with the presence, location, and extent of cerebral ischemic lesions. Methods. A prospective analysis of 180 patients aged 50?70 years, divided into three groups (asymptomatic carotid stenosis, symptomatic carotid stenosis, and controls) was made. We assessed demographic characteristics, vascu-lar risk factors, ultrasound examination of the carotid arter-ies, computerized tomography (CT), magnetic resonance imaging (MRI) of the brain, and neuropsychological testing. Results. The brain CT findings on admission showed is-chemic lesions in the left hemisphere in 13.3% of patients in the asymptomatic group and in 41% of those in the symp-tomatic group. In the right hemisphere, lesions were regis-tered in 10% of the asymptomatic patients and in 46.7% of the symptomatic patients. The difference between groups was statistically significant. The lesion volumes measured on CT and MRI scans were significantly different (p < 0.001) between groups with asymptomatic and symptomatic carot-id stenosis. The degree of cognitive impairment, measured by the Addenbrooke's Cognitive Examination Revised (ACE-R), was significantly different between the groups (p < 0.05), with the most severe deficit in the symptomatic group. Conclusion. Our study has shown that cognitive impairment was more severe in patients with symptomatic carotid stenosis, compared to the patients with asymptomat-ic carotid stenosis.

Post-stroke Cognitive Impairment and Malnutrition in the Elderly (PCIME): study design and protocol

Purpose

Stroke and dementia are burdensome non communicable diseases but preventable. A joint prevention of stroke and dementia requires a comprehensive approach by controlling common risk factors. Little is known about the role of malnutrition in post-stroke cognitive impairments. The main aim of this study is to evaluate the presence of cognitive impairment after stroke and its association with malnutrition.

Methods

Post-stroke Cognitive Impairment and Malnutrition in the Elderly (PCIME) is a prospective hospital-based cohort study, started on January 2nd, 2018 at Ziaeian Hospital, a referral center for elderly, Tehran, Iran, Middle East. We have used a battery of neuropsychiatric tests, including the Montreal Cognitive Assessment and Mini-Mental State Examination. We have assessed malnutrition using the Mini Nutritional Assessment and Geriatric Nutritional Risk Index.

Conclusion

PCIME will enable us to assess the role of malnutrition in development of post stroke dementia. This study will help clinicians and researchers develop preventive measures to reduce the burden of stroke and dementia.

Stroke disease-specific quality of life trajectories after rehabilitation discharge and their sociodemographic and clinical associations: A longitudinal, multicentre study

AIM

To investigate the longitudinal growth trajectories of disease-specific quality of life (QoL) dimensions and their associations over 1 year.

DESIGN

A longitudinal design. Data were collected between February 2015-May 2017.

METHODS

Four hundred and fifteen stroke survivors (mean age 70.6 years; 81% ischaemic stroke) were recruited after discharge from rehabilitation hospitals and were followed up every 3 months for 1 year. Changes in Stroke Impact Scale (SIS) dimension scores were evaluated using hierarchical linear models (HLMs) and linear, logarithmic, quadratic, and cubic time slope.

RESULTS

We observed a significant linear and quadratic increase in most SIS dimensions from the baseline to 12-month follow-up, especially in physical dimensions. The communication dimension was stable over time, while the memory dimension increased only linearly. Higher physical dimension scores were significantly associated with lower age, hypercholesterolaemia, and better physical functioning at baseline, while higher communication was associated with lower age, better physical functioning, and a diagnosis of peripheral vascular disease. Better memory was associated with lower age, married status, better physical functioning, and left-hemisphere stroke. Better participation was associated with lower age and better physical functioning. No significant associations were observed for emotion.

CONCLUSIONS

This study provides important information about the trajectories of stroke survivors' specific QoL and their associated variables.

IMPACT

Stroke has a great impact on stroke survivors' QoL. Disease-specific QoL significantly increases from the baseline to 12-month follow-up, especially in physical dimensions. Lower age, hypercholesterolaemia, better physical functioning, and diagnosis of peripheral vascular disease seem to be associated with better QoL. Through the analyses of associated variables, we identified stroke survivors who are more at risk and who need more tailored interventions to improve their physical, psychological, emotional, and social dimensions.

Functional limitations and cognitive impairment predict the outcome of dysphagia in older patients after an acute neurologic event

BACKGROUND

Dysphagia prevalence increases with age and a significant contribution is given by stroke survivors; its treatment is mainly based on rehabilitation, but outcome cannot be easily predicted.

OBJECTIVE

The aim of this study is to detect possible predictors of the outcome of dysphagia in patients beginning rehabilitation after a major Central Nervous System injury.

METHODS

Dysphagia severity was measured in 95 consecutive patients (71 with ischemic or hemorrhagic stroke) upon admission to our neurorehabilitation unit and at discharge, during the year 2017. The initial evaluation included also demographic data, functional and geriatric multidimensional assessment, laboratory test results and comorbidities. Their possible predictive value on the degree of recovery of the swallowing process at discharge has been analyzed.

RESULTS

Poor functional conditions and the presence of cognitive impairment on admission appear to be associated with a worse outcome of dysphagia at discharge. A significant correlation exists between scores at functional scales at the beginning of rehabilitation and dysphagia score at discharge. Patients with cognitive impairment at the beginning (n = 60) showed a significantly lower degree of recovery of dysphagia at discharge.

CONCLUSION

Other factors, beside the degree of dysphagia itself, are important to predict its outcome. Their knowledge not only allows an initial prognostic assessment; it can also be useful to decide which aspects should receive greater attention when treating patients with dysphagia.

Prevalence and factors associated with memory disturbance and dementia after acute ischemic stroke

Prevalence and risk factors associated with memory disturbance and dementia were determined in acute ischemic stroke (AIS) patients in hospitals before discharge, three and six months after stroke. A prospective cohort study was conducted during January-December 2017 with 401 AIS patients admitted to Srinagarind Hospital, Khon Kaen Hospital and Chum Phae Hospital, Khon Kaen, Thailand. The demographics and clinical characteristics, previous illness and past medical history, and laboratory test results of the patients were collected from the medical records, while depression screening, NIH stroke scale (NIHSS) scoring and mini mental state examination (MMSE) were performed using particular medical record forms. The prevalence of memory disturbance and dementia was 56.6, 41.6 and 38.2% before discharge, three and six months after stroke, respectively. Based on logistic regression analysis, age, education and stroke severity were the risk factors associated with the studied disorders before discharge and three months after stroke. Meanwhile, age and education were the risk factors for six months after stroke. Our findings suggested that the prevalence of memory disturbance and dementia remained high at all study periods.

Memory Alterations and White Matter Hyperintensities in Elderly Patients With Hypertension: The ADELAHYDE-2 Study

OBJECTIVES

The longitudinal ADELAHYDE-2 study aims to identify the factors associated with cognitive impairment/decline and white matter hyperintensities burden.

METHODS

Longitudinal single-center study comprising two visits separated by approximately 7 years. A total of 131 patients completed the two visits. The primary outcome was global memory composite scale, while the secondary outcome was white matter hyperintensities (WMH/Fazekas scale) load.

RESULTS

Global memory at visit 2 (V2) was largely influenced by age, smoking status, glycated hemoglobin, and history of stroke already present at visit 1 (V1). These variables accounted for ∼51% of the memory alterations at V2. WMH at V2 was likely influenced by age, left ventricular hypertrophy, diabetes mellitus, carotid intima-media thickness, and body mass index at V1. These findings accounted for ∼37% of the WMH changes at V2. Increase in pulse wave velocity from V1 to V2 showed a trend for association with memory deterioration (adjusted estimates = 0.06; P = .067), whereas smoking and increase in systolic blood pressure (trend) were associated with an increment in WMH (adjusted estimates = 0.49; P = .047 and adjusted estimates = 0.01; P = .08, respectively). On the other hand, angiotensin-converting enzyme inhibitor/angiotensin receptor blockers and statins (trend) were likely to be protective (adjusted estimates for angiotensin-converting enzyme inhibitor/angiotensin receptor blockers = -0.49; P = .049, and adjusted estimates for statins = -0.46; P = .055).

CONCLUSIONS

Several readily identifiable factors are associated with memory deterioration and WMH, many of which are potentially modifiable. Interventions aimed to control these risk factors need to be tested prospectively in order to assess their cognitive protective value.

Paeoniflorin improves regional cerebral blood flow and suppresses inflammatory factors in the hippocampus of rats with vascular dementia

OBJECTIVE

To explore the delayed neuroprotection induced by paeoniflorin (PF), the principal component of Paeoniae radix prescribed in Chinese medicine, and its underlying mechanisms in rats subjected to vascular dementia (VD).

METHODS

A rat model of VD was induced by bilateral common carotid arteries occlusion (BCCAO). Low-dose or high-dose PF (20 or 40 mg/kg once per day) was administrated for 28 days after VD. The behavioral analysis of rat was measured by water morris. Regional cerebral blood volume (rCBV), regional cerebral blood flflow (rCBF) and mean transit time (MTT) were measured in the bilateral hippocampus by perfusion-weighted imaging (PWI). The levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were measured by commercially available enzyme-linked immunosorbent assay kits. Protein levels were evaluated by western blot analysis. mRNA levels were evaluated by real time-polymerase chain reaction. Western blotting was used to estimate p65 translocation.

RESULTS

The behavioral analysis showed that PF could decrease the escape latency time (P<0.05), and increase the residence time of the original platform quadrant and the across platform frequency in water maze in VD rats (P<0.05). Likewise, PF remarkably promoted the rCBV (P<0.05), rCBF and decreased per minute MTT (P<0.05) in hippocampus of VD rats. Furthermore, PF decreased the release of IL-1β, IL-6 and TNF-α as well as inhibited the mRNA expression of IL-1β, IL-6 and TNF-α in the hippocampus of VD rats (P<0.05 or P<0.01). PF also could decrease the protein expressions of inducible nitric oxide synthase and cyclooxygenase-2 in the hippocampus of VD rats (P<0.05 or P<0.01). In addition, PF signifificantly inhibited the nuclear factor κB (NF-κB) pathway in the hippocampus of VD rats.

CONCLUSIONS

PF signifificantly attenuates cognitive impairment, improves hippocampus perfusion and inhibits inflflammatory response in VD rats. In addition, the anti-inflflammatory effects of PF might be due to inhibiting the NF-κB pathway. PF may be a potential clinical application in improving VD.

Are we providing the best possible care for dementia patients?

SUMMARY 

Healthcare for patients with dementia is often reactive, poorly organized and fragmented. We discuss opportunities for improvements in the care of individuals living with dementia at home that can be implemented by physicians in their practices today. In particular, we argue that systematic identification and diagnosis of cognitive impairment and dementia in their early stages, coupled with a coherent, evidence-informed management framework, would benefit patients with dementia substantially and ease the burden of their caregivers. We emphasize that dementia influences all aspects of patient care, and each medical decision must be passed through the filter of knowledge that patients with dementia have special needs that can be identified and addressed.

Neuropsychological and neuroimaging markers in prediction of cognitive impairment after ischemic stroke: a prospective follow-up study

BACKGROUND

There are few longitudinal studies with controversial results examining delayed changes in cognition after ischemic stroke and predictive values of neuropsychological and neuroimaging markers.

OBJECTIVE

The objectives of this study were to evaluate the delayed changes in cognition in poststroke patients and their relationship to the neuropsychological and neuroimaging markers measured during the acute poststroke phase.

METHODS

Eighty-five first-ever stroke inpatients (mean age 65.6±5.6 years) without previous cognitive complaints were prospectively evaluated with a comprehensive neuropsychological battery at the 5th day and the 1st, 6th, and 12th months. A wide range of clinical, radiological, and neuropsychological variables were examined.

RESULTS

Our results showed significantly poorer performance on mini-mental state examination, memory, attention/executive functions, and processing speed in patients with stroke in comparison with stroke-free cognitively intact controls. Multiple regression analysis revealed that hippocampal atrophy is the strongest predictor of delayed cognitive impairment. Secondary divided subgroups according to Isaacs Set Test (IST) score showed that patients with IST score ≤28 had different patterns of cognitive and neurological impairment after 1 year. Baseline impairments in attention/executive functions and memory were associated with development of dementia in poststroke patients.

CONCLUSION

Executive functioning deficit appears to have a predictive power for cognitive impairment progression. The study suggests that IST as a screening test has a potential to be a reliable and quick tool for poststroke cognitive impairment evaluation and delayed cognitive and neurological outcome. Hippocampal atrophy was the strongest predictor for cognitive impairment outcome, even in poststroke cognitive impairment. The findings may set the stage for better poststroke management.