Cognitive impairment after stroke

Knowledge domain and emerging trends in post-stroke cognitive impairment: a bibliometric analysis

Background

Cognitive impairment is an important cause of disability and death among the elderly. One of the most important risk factors is stroke. Post-stroke cognitive impairment (PSCI) not only diminishes the quality of life for patients but also increases the burden on families and society. But PSCI can be mitigated through early intervention. Cerebral small vessel disease (CSVD) is one of the significant causes of stroke and has garnered considerable attention in PSCI. Therefore, this study aims to identify research priorities and trends in PSCI through bibliometric analysis, and further explore the role played by CSVD in PSCI.

Methods

In this study, we performed a systematic search in the Science Citation Index Expanded (SCI-E) of the Web of Science Core Collection (WoSCC). VOSviewer, CiteSpace and Origin were mainly used to visualize the research focus and trend in PSCI. In addition, we screened the retrieved literature again, and performed keyword analysis on the studies related to CSVD.

Results

A total of 1,943 publications were retrieved in the field of PSCI in this study, with consistent upward trend in annual publications in recent years. Pendlebury was an important leader in PSCI research. Capital Medical University was in the leading position judging from the number of publications. China had the highest number of publications in this field. The journal Stroke had the strongest international influence in this field. Keywords such as "functional connectivity," "tool," "systematic review," and "meta-analysis" have been revealed to have momentous impact on PSCI in recent years. In the further analysis of PSCI and CSVD, "hypertension," "white matter hyperintensities (WMH)," "cerebral microbleeds (CMBs)," and "cerebral amyloid angiopathy (CAA)" received extensive attention.

Conclusion

The study of PSCI is still in the development stage. This study systematically summarizes the progress and development trend in the field of PSCI, and further explores the relationship between CSVD and PSCI through hypertension and magnetic resonance imaging markers. This study is of great significance for researchers to quickly understand the development of PSCI, but also helps them understand future directions, and provides important insights for the prevention and treatment of PSCI.

Altered Corticospinal and Intracortical Excitability After Stroke: A Systematic Review With Meta-Analysis

BACKGROUND

Intracortical inhibitory/faciliatory measures are affected after stroke; however, the evidence is conflicting.

OBJECTIVE

This meta-analysis aimed to investigate the changes in motor threshold (MT), motor evoked potential (MEP), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF), and identify sources of study variability using a machine learning approach.

METHODS

We identified studies that objectively evaluated corticospinal excitability and intracortical inhibition/facilitation after stroke using transcranial magnetic stimulation. Pooled within- (ie, affected hemisphere [AH] vs unaffected hemisphere [UH]) and between-subjects (ie, AH and UH vs Control) standardized mean differences were computed. Decision trees determined which factors accurately predicted studies that showed alterations in corticospinal excitability and intracortical inhibition/facilitation.

RESULTS

A total of 35 studies (625 stroke patients and 328 healthy controls) were included. MT was significantly increased and MEP was significantly decreased (ie, reduced excitability) in the AH when compared with the UH and Control (P < .01). SICI was increased (ie, reduced inhibition) for the AH when compared with the UH, and for the AH and UH when compared with Control (P < .001). ICF was significantly increased (ie, increased facilitation) in the AH when compared with UH (P = .016) and decreased in UH when compared with Control (P < 0.001). Decision trees indicated that demographic and methodological factors accurately predicted (73%-86%) studies that showed alterations in corticospinal and intracortical excitability measures.

CONCLUSIONS

The findings indicate that stroke alters corticospinal and intracortical excitability measures. Alterations in SICI and ICF may reflect disinhibition of the motor cortex after stroke, which is contrary to the notion that stroke increases inhibition of the affected side.

Breathing Exercises for Improving Cognitive Function in Patients with Stroke

Patients with stroke may experience a certain degree of cognitive decline during the period of recovery, and a considerable number of such patients have been reported to show permanent cognitive damage. Therefore, the period of recovery and rehabilitation following stroke is critical for rapid cognitive functional improvements. As dysfunctional breathing has been reported as one of the factors affecting the quality of life post stroke, a number of studies have focused on the need for improving the breathing function in these patients. Numerous breathing exercises have been reported to enhance the respiratory, pulmonary, cognitive, and psychological functions. However, scientific evidence on the underlying mechanisms by which these exercises improve cognitive function is scattered at best. Therefore, it has been difficult to establish a protocol of breathing exercises for patients with stroke. In this review, we summarize the psychological, vascular, sleep-related, and biochemical factors influencing cognition in patients and highlight the need for breathing exercises based on existing studies. Breathing exercises are expected to contribute to improvements in cognitive function in stroke based on a diverse array of supporting evidence. With relevant follow-up studies, a protocol of breathing exercises can be developed for improving the cognitive function in patients with stroke.

Validation of a New Cognitive Screening Method for Stroke Patients

Objective

Two million adults under fifty years of age have a cerebral stroke every year worldwide. Neuropsychological assessment is the best way to identify poststroke cognitive dysfunction, but it is often time-consuming and can be tiring for the patient, and hospitals vary in their availability of neuropsychological expertise. A valid and reliable cognitive screening method could be advantageous in identifying patients who need comprehensive neuropsychological examination. Our purpose in this study was to validate a newly developed cognitive screening method as an identifier of cognitive dysfunction after stroke in working-aged patients.

Methods

We analyzed new cognitive screening method concurrent validity by comparing it in two groups formed on the basis of a comprehensive neuropsychological examination for 77 stroke patients. We identified the best balance of sensitivity and specificity by using receiver operating characteristic curve analysis and investigated the impact of the sociodemographic variables to the screening method total score variation.

Results

We found a significant correlation between the method's total score and performance in neuropsychological examination. The cognitive method's internal consistency was strong; Cronbach's alpha for all items was .818. The best balance of sensitivity (88%) and specificity (50%) was found at a total score cut point of 138. Subjects' age and length of education were each responsible for 10% of total score variation.

Conclusions

This study shows promising results for this new cognitive screening tool's ability to identify poststroke cognitive decline and patients' need for further detailed neuropsychological examination.

Effect of a dual-task program with different cognitive tasks applied to stroke patients: A pilot randomized controlled trial

BACKGROUND

Dual-task training using one walking and one cognitive task is effective in improving post-stroke motor functions.

OBJECTIVE

We aimed to investigate the effectiveness of dual-task training using various cognitive tasks for the assessment of attention, executive function, and motor function in stroke patients.

METHODS

This was a single-center, randomized trial involving 30 stroke patients who were divided into a dual-task (test) group (n = 15) using different cognitive tests, and a conventional occupational therapy (control) group (n = 15). In both groups, interventions were conducted 18 times, at 30 minutes per session, 3 sessions per week, for 6 weeks. Primary outcome measures were the Trail Making Test A&B, the Digit Span Test (DST) Forward and Backward, and the Stroop (ST) Color and Word test. Secondary outcome measures were the Fugl-Meyer Assessment, the Modified Functional Reach Test, and the Berg Balance Scale. Each test was applied pre-and post- intervention.

RESULTS

Post-intervention, the dual-task group showed a significantly stronger effect than the occupational therapy group in the DST-Forward (p = 0.04), DST-Backward (p = 0.001), ST-Color (p = 0.023), and Berg Balance Scale (p = 0.009) assessments.

CONCLUSIONS

Dual-task training using various cognitive tasks had a greater positive effect than conventional occupational therapy on auditory attention, memory span, executive function, and balance.

Risk Factors for Falls in Community Stroke Survivors: A Systematic Review and Meta-Analysis

OBJECTIVE

To identify the risk factors for falls in community stroke survivors.

DATA SOURCES

A comprehensive search for articles indexed in MEDLINE, Embase, CINAHL, PsycINFO, Cochrane Library, and Web of Science databases was conducted.

STUDY SELECTION

Prospective studies investigating fall risk factors in community stroke survivors were included. Reviewers in pair independently screened the articles and determined inclusion through consensus. Studies meeting acceptable quality rating using the Q-Coh tool were included in the meta-analysis.

DATA EXTRACTION

Data extraction was done in duplicate by 4 reviewers using a standardized data extraction sheet and confirmed by another independent reviewer for completeness and accuracy.

DATA SYNTHESIS

Twenty-one articles met the minimum criteria for inclusion; risk factors investigated by ≥3 studies (n=16) were included in the meta-analysis. The following risk factors had a strong association with all fallers: impaired mobility (odds ratio [OR], 4.36; 95% confidence interval [CI], 2.68-7.10); reduced balance (OR, 3.87; 95% CI, 2.39-6.26); use of sedative or psychotropic medications (OR, 3.19; 95% CI, 1.36-7.48); disability in self-care (OR, 2.30; 95% CI, 1.51-3.49); depression (OR, 2.11; 95% CI, 1.18-3.75); cognitive impairment (OR, 1.75; 95% CI, 1.02-2.99); and history of fall (OR, 1.67; 95% CI, 1.03-2.72). A history of fall (OR, 4.19; 95% CI, 2.05-7.01) had a stronger association with recurrent fallers.

CONCLUSIONS

This study confirms that balance and mobility problems, assisted self-care, taking sedative or psychotropic medications, cognitive impairment, depression, and history of falling are associated with falls in community stroke survivors. We recommend that any future research into fall prevention programs should consider addressing these modifiable risk factors. Because the risk factors for falls in community stroke survivors are multifactorial, interventions should be multidimensional.

Electro-acupuncture ameliorates cognitive impairment via improvement of brain-derived neurotropic factor-mediated hippocampal synaptic plasticity in cerebral ischemia-reperfusion injured rats

A previous study by our group found that electro-acupuncture (EA) at the Shenting (DU24) and Baihui (DU20) acupoints ameliorates cognitive impairment in rats with cerebral ischemia-reperfusion (I/R) injury. However, the precise mechanism of action has remained largely unknown. The present study investigated whether brain-derived neurotropic factor (BDNF) mediates hippocampal synaptic plasticity as the underlying mechanism. Rats were randomly divided into three groups: The sham operation control (Sham) group, the focal cerebral ischemia-reperfusion (I/R) group, and the I/R with EA treatment (I/R+EA) group. The I/R+EA group received EA treatment at the Shenting (DU24) and Baihui (DU20) acupoints after the operation. EA treatment was found to ameliorate neurological deficits (P<0.05) and reduce the cerebral infarct volume (P<0.01). In addition, EA improved cognitive function in cerebral I/R-injured rats (P<0.05). Furthermore, EA treatment promoted synaptic plasticity. Simultaneously, EA increased the hippocampal expression of BDNF, its high-affinity tropomyosin receptor kinase B (TrkB) and post-synaptic density protein-95 (PSD-95) in the rats with cerebral I/R injury. Collectively, the findings suggested that BDNF-mediated hippocampal synaptic plasticity may be one mechanism via which EA treatment at the Shenting (DU24) and Baihui (DU20) acupoints improves cognitive function in cerebral I/R injured rats.

Severe carotid artery stenosis evaluated by ultrasound is associated with post stroke vascular cognitive impairment

BACKGROUND

Acute ischemic stroke has been recognized as one key cause of vascular cognitive impairment (VCI). The purpose of this study was to evaluate the correlation between carotid artery stenosis and post VCI in acute ischemic stroke patients.

METHODS

In this study, B-mode ultrasound was applied to measure the degree of carotid artery stenosis. After 1 year, the stroke patients' cognitive function was assessed by the mini-mental state examination (MMSE) score. The relationship between the VCI and degree of carotid artery stenosis was evaluated by multivariate regression analysis.

RESULTS

VCI was observed in 136 (37.2%) of the 365 participants. High degree of carotid artery stenosis was significantly correlated with VCI (p < .01), and this correlation remained unchanged even adjustment for age, gender, education level, stroke features, and vascular risk factors.

CONCLUSIONS

These findings indicate that high-grade stenosis of carotid artery is positively correlated with post stroke VCI in patients with acute ischemic stroke. The evaluation of 1 year post stroke cognitive function may be a potential tool for screening stroke patients at risk of VCI.

Robotic neurorehabilitation in patients with chronic stroke: psychological well-being beyond motor improvement

Although gait abnormality is one of the most disabling events following stroke, cognitive, and psychological impairments can be devastating. The Lokomat is a robotic that has been used widely for gait rehabilitation in several movement disorders, especially in the acute and subacute phases. The aim of this study was to evaluate the effectiveness of gait robotic rehabilitation in patients affected by chronic stroke. Psychological impact was also taken into consideration. Thirty patients (13 women and 17 men) affected by chronic stroke entered the study. All participants underwent neurological examination with respect to ambulation, Ashworth, Functional Independence Measure, and Tinetti scales to assess their physical status, and Hamilton Rating Scale for Depression, Psychological General Well-being Index, and Coping Orientation to Problem Experienced to evaluate the Lokomat-related psychological impact before and after either a conventional treatment or the robotic training. During each rehabilitation period (separated by a no-treatment period), patients underwent a total of 40 1 h training sessions (i.e. five times a week for 8 weeks). After the conventional treatment, the patients did not achieve a significant improvement in the functional status, except balance (P<0.001) and walking ability (P<0.01), as per the Tinetti scale. Indeed, after the robotic rehabilitation, significant improvements were detected in almost all the motor and psychological scales that we investigated, particularly for Psychological General Well-being Index and Coping Orientation to Problem Experienced. Manual and robotic-assisted body weight-supported treadmill training optimizes the sensory inputs relevant to step training, repeated practice, as well as neuroplasticity. Several controlled trials have shown a superior effect of Lokomat treatment in stroke patients' walking ability and velocity in particular. Therefore, our preliminary results proved that active robotic training not only facilitates gait and physical function but also the psychological status, even in patients affected by chronic stroke.

Electroacupuncture improves cognitive ability following cerebral ischemia reperfusion injury via CaM-CaMKIV-CREB signaling in the rat hippocampus

The aim of the present study was to investigate the effect of electroacupuncture (EA) on cognitive deficits, and the underlying mechanism following cerebral ischemia-reperfusion (I/R) via the calmodulin (CaM)-calmodulin-dependent protein kinase type IV (CaMKIV)-cyclic adenosine monophosphate response elements binding protein (CREB) intracellular signaling pathway in the hippocampus. In total, 45 adult female Sprague-Dawley rats were randomly divided into three groups, namely the sham group, the middle cerebral artery occlusion (MCAO) group and the MCAO + EA group. Rats in the MCAO and MCAO + EA groups were modeled for post-stroke cognitive impairment. EA was performed at the Baihui and Shenting acupuncture points for 30 min/day for one week in the MCAO + EA group. Behavioral testing was analyzed using a step-down apparatus, while 2,3,5-triphenyl tetrazolium chloride was used to detect the infarct volume and lesion size. In addition, CaM activity was assessed by cyclic nucleotide-dependent phosphodiesterase analysis, and the protein expression levels of CaM, CaMKIV, phosphorylated (p)-CaMKIV, CREB and p-CREB were analyzed by western blot analysis. The cerebral I/R injured rat model in the MCAO group was established successfully with regard to the infarct volume and neuronal lesion size, as compared with the sham group. EA was demonstrated to effectively improve the cognitive ability, as measured by the step-down apparatus test, and decrease the infarct volume when compared with the MCAO group (P<0.05). The step-down apparatus test for the EA-treated rats revealed improved learning and reduced memory impairment when compared with the MCAO group. Furthermore, CaM activity and CaM protein expression levels in the MCAO + EA group were lower compared with those in the MCAO group (P<0.05). By contrast, the protein expression levels of CaMKIV, p-CaMKIV, CREB and p-CREB were significantly reduced in the MCAO group when compared with the sham group (P<0.05), although the expression levels increased following EA treatment when compared with the MCAO group (P<0.05). Therefore, cognitive repair benefited from EA, and the main intracellular signaling pathway in the hippocampus was mediated by CaM-CaMKIV-CREB. EA effectively inhibited the expression and activity of CaM, while further enhancing the expression of CaMKIV and CREB, and their associated phosphorylated functions.

Correlates of Depressive Symptoms in Older Adults with Diabetes

Investigators examined correlates of depressive symptoms within a sample of older adults with diabetes. Participants completed a structured telephone interview with measures including depressive symptoms, health conditions, cognitive function, and diabetes distress. Correlations and hierarchical linear regression models were utilized to examine bivariate and covariate-adjusted correlates of depressive symptoms. The sample included 246 community-dwelling adults with diabetes (≥ 65 years old). In bivariate analyses, African Americans, individuals with specific health issues (neuropathy, stroke, respiratory issues, arthritis, and cardiac issues), and those with higher levels of diabetes distress reported more depressive symptoms. Older age, higher education, more income, and better cognitive function were inversely associated with depressive symptoms. In the final covariate-adjusted regression model, stroke (B = .22, p < .001), cognitive function (B = -.14, p < .01), and higher levels of diabetes-related distress (B = .49, p < .001) each were uniquely associated with more depressive symptoms. Diabetes distress partially mediated the associations between cardiac issues and depressive symptoms and between cognitive function and depressive symptoms. Findings suggest that interventions targeted at helping older adults manage their diabetes-related distress and reducing the likelihood of experiencing additional health complications may reduce depressive symptoms within this population.

Neuropsychiatric symptoms in patients with vascular dementia in mainland China

Background

Neuropsychiatric deficits can induce marked disability in patients with dementia and increase caregiver distress. Several studies have found that neuropsychiatric symptoms are common both in patients with Alzheimer’s disease (AD) and patients with vascular dementia (VaD). However, there are few studies of the neuropsychiatric disturbances in large clinical samples of patients with mixed (cortical - subcortical) VaD from mainland China. This study aimed to investigate the neuropsychiatric symptoms in VaD patients in mainland China.

Methods

Eighty patients with mixed VaD for over 6 months duration, and their caregivers (VaD group), were recruited for interview in Zhongnan Hospital of Wuhan University, from June 2010 to June 2012. Eighty age- and sex-matched normal volunteers (control group) were interviewed at the same time. The Mini Mental State Examination (MMSE) and the Neuropsychiatric Inventory (NPI) were administered to the VaD patients, their caregivers, and normal volunteers. Group differences were analyzed using the unpaired t-test.

Results

The total mean scores of the NPI in the VaD group were higher than in the control group (P < 0.01). The subscale scores of NPI, including delusions, hallucinations, depression, apathy, irritability, agitation, aberrant motor behavior, and change in appetite were significantly higher in the VaD group than in the control group (P < 0.05–0.01). Compared with the mild VaD subgroup, the NPI subscale scores of apathy, irritability and total scores were significantly higher in the moderate VaD subgroup (P < 0.05–0.01); the NPI subscale scores of anxiety, apathy, irritability, and total scores were significantly higher in the severe VaD subgroup (P < 0.01). Compared with the moderate VaD subgroup, the NPI subscale scores of anxiety and apathy were significantly higher in the severe VaD subgroup (P < 0.05–0.01).

Conclusions

Neuropsychiatric symptoms, such as hallucination, anxiety, apathy, irritability and aberrant action behavior, are common in patients with mixed VaD from mainland China; anxiety and apathy were more pronounced in the subgroup of severe VaD patients.

Correlates of functional outcome among stroke survivors in a developing country--a prospective community-based study from India

Stroke survivors (SS) are rising with higher incidence of stroke in developing countries. In addition to physical impairment, other factors such as cognition, social interaction, and depression determine the functional outcome after stroke. Considering the paucity of data from developing countries, we planned to determine the change in various functional parameters among SS. This community-based prospective study was carried out in Kolkata, India among 283 SS between 2006 and 2010. Functional outcome was assessed at baseline and at 3 annual follow-up visits using validated tools. A stepwise regression analysis was performed with demographic and stroke-related covariates against various measures of functional outcome. Result showed that mean Barthel Index score at baseline was 76.4 ± 30.8. Bengali version of mental status examination and Geriatric Depression Scale scores trended down over time with a negative regression coefficient of -.2061 (standard error [SE], .0937) and -.4488 (SE, .2145). Other outcomes did not change. Female gender, depression, and cognitive dysfunction had an unfavorable impact, whereas education correlated positively. In conclusions female gender and neuropsychiatric disturbances showed poor functional outcome compared with education, which correlates with better outcome. This information will be helpful for patients in developing countries for planning stroke rehabilitation.

The synergistic effect of acupuncture and computer-based cognitive training on post-stroke cognitive dysfunction: a study protocol for a randomized controlled trial of 2 × 2 factorial design

Background

Stroke is one of the most common causes of cognitive impairment. Up to 75% of stroke survivors may be considered to have cognitive impairment, which severely limit individual autonomy for successful reintegration into family, work and social life. The clinical efficacy of acupuncture with Baihui (DU20) and Shenting (DU24) in stroke and post-stroke cognitive impairment has been previously demonstrated. Computer-assisted cognitive training is part of conventional cognitive rehabilitation and has also shown to be effective in improvement of cognitive function of affected patients. However, the cognitive impairment after stroke is so complexity that one single treatment cannot resolve effectively. Besides, the effects of acupuncture and RehaCom cognitive training have not been systematically compared, nor has the possibility of a synergistic effect of combination of the two therapeutic modalities been evaluated. Our primary aim of this trial is to evaluate the synergistic effect of acupuncture and RehaCom cognitive training on cognitive dysfunction after stroke.

Method/Design

A randomized controlled trial of 2 × 2 factorial design will be conducted in the Rehabilitation Hospital Affiliated to Fujian University of Traditional Chinese Medicine. A total of 240 patients with cognitive dysfunction after stroke who meet the eligibility criteria will be recruited and randomized into RehaCom training group, acupuncture group, a combination of both or control group in a 1:1:1:1 ratio. All patients will receive conventional treatment. The interventions will last for 12 weeks (30 min per day, Monday to Friday every week). Evaluations will be conducted by blinded assessors at baseline and again at 4, 8 and 12 weeks. Outcome measurements include mini–mental state examination (MMSE), Montreal cognitive assessments (MoCA), functional independence measure scale (FIM) and adverse events.

Discussion

The results of this trial are expected to clarify the synergistic effect of acupuncture and RehaCom cognitive training on cognitive dysfunction after stroke. Furthermore, to confirm whether combined or alone of acupuncture and RehaCom cognitive training, is more effective than conventional treatment in the management of post-stroke cognitive dysfunction.

Trial registration

Chinese Clinical Trial Registry: ChiCTR-TRC-13003704.

Registration date: 4 September, 2013.

Catalpol Induces Neuroprotection and Prevents Memory Dysfunction through the Cholinergic System and BDNF

To investigate the role and mechanism of catalpol on neuroprotective effects and memory enhancing effects simultaneously, neuroprotective effects of catalpol were assessed by neurological deficits score, TTC staining, and cerebral blood flow detecting. Morris water maze was employed to investigate its effects on learning and memory and then clarify its possible mechanisms relating the central cholinergic system and BDNF. Edaravone and oxiracetam were used for positive control drugs based on its different action. Results showed that catalpol and edaravone significantly facilitated neurological function recovery, reduced infarction volume, and increased cerebral blood flow in stroke mice. Catalpol and oxiracetam decreased the escape latency significantly and increased the numbers of crossing platform obviously. The levels of ACh, ChAT, and BDNF in catalpol group were increased in a dose-dependent manner, and AChE declined with a U-shaped dose-response curve. Moreover, the levels of muscarinic AChR subtypes M₁ and M₂ in hippocampus were considerably raised by catalpol. These results demonstrated that catalpol may be useful for neuroprotection and memory enhancement, and the mechanism may be related to the central cholinergic system.

Electroacupuncture ameliorates cognitive impairment through inhibition of NF-κB-mediated neuronal cell apoptosis in cerebral ischemia-reperfusion injured rats

Cognitive impairment is a serious mental deficit following stroke that severely affects the quality of life of stroke survivors. Nuclear factor‑κB (NF-κB)-mediated neuronal cell apoptosis is involved in the development of post-stroke cognitive impairment; therefore, it has become a promising target for the treatment of impaired cognition. Acupuncture at the Baihui (DU20) and Shenting (DU24) acupoints is commonly used in China to clinically treat post‑stroke cognitive impairment; however, the precise mechanism of its action is largely unknown. In the present study, we evaluated the therapeutic efficacy of electroacupuncture against post-stroke cognitive impairment and investigated the underlying molecular mechanisms using a rat model of focal cerebral ischemia-reperfusion (I/R) injury. Electroacupuncture at Baihui and Shenting was identified to significantly ameliorate neurological deficits and reduce cerebral infarct volume. Additionally, electroacupuncture improved learning and memory ability in cerebral I/R injured rats, demonstrating its therapeutic efficacy against post-stroke cognitive impairment. Furthermore, electroacupuncture significantly suppressed the I/R-induced activation of NF-κB signaling in ischemic cerebral tissues. The inhibitory effect of electroacupuncture on NF-κB activation led to the inhibition of cerebral cell apoptosis. Finally, electroacupuncture markedly downregulated the expression of pro-apoptotic Bax and Fas, two critical downstream target genes of the NF-κB pathway. Collectively, our findings suggest that inhibition of NF-κB‑mediated neuronal cell apoptosis may be one mechanism via which electroacupuncture at Baihui and Shenting exerts a therapeutic effect on post-stroke cognitive impairment.

Feasibility and effectiveness of circuit training in acute stroke rehabilitation

BACKGROUND

Task-specificity, repetition and progression are key variables in the acquisition of motor skill however they have not been consistently implemented in post-stroke rehabilitation.

OBJECTIVE

To evaluate the effectiveness of a stroke rehabilitation plan of care that incorporated task-specific practice, repetition and progression to facilitate functional gain compared to standard physical therapy for individuals admitted to an inpatient stroke unit.

METHODS

Individuals participated in either a circuit training (CTPT) model (n = 72) or a standard (SPT) model (n = 108) of physical therapy, 5 days/week. Each 60 minute circuit training session, delivered according to severity level, consisted of four functional mobility tasks. Daily exercise logs documented both task repetition and progression.

RESULTS

The CTPT model was successfully implemented in an acute rehabilitation setting. The CTPT group showed a significantly greater improved change in gait speed from hospital admission to discharge than the SPT group (0.21 ± 0.25 m/sec vs. 0.13 ± 0.22 m/sec; p = 0.03). The difference between groups occurred primarily among those who were ambulatory upon admission. There were no significant differences between the two cohorts at 90 days post-stroke as measured by the FONE-FIM, SF-36 and living location.

CONCLUSIONS

Therapy focused on systematically progressed functional tasks can be successfully implemented in an inpatient rehabilitation stroke program. This circuit-training model resulted in greater gains in gait velocity over the course of inpatient rehabilitation compared to the standard model of care. Community-based services following hospital discharge to maintain these gains should be included in the continuum of post-stroke care.

Post-stroke cognitive impairment at 3 months

BACKGROUND

Vascular cognitive impairment, being the only treatable cause of dementia in the early stages, and having a diverse etiology, requires sensitive criteria for definition.

AIM

This study aimed to study cognitive functions at 3 months post-stroke, utilising the Mini mental scale examination (MMSE) and the Frontal assessment battery (FAB), and to correlate the same with subgroups of ischemic stroke.

RESULTS

164 patients were studied, 108 of these having multiple infarcts. Pure cortical infarcts were seen in 41 patients. At 3 months, 112/164 patients had MMSE more than 24, with no frontal executive dysfunction. MMSE score less than 24 was seen in 24 patients, all of them having FAB score below 10. Normal MMSE with impaired FAB was seen in 28 patients.

CONCLUSIONS

Impairment on either the MMSE or the FAB was thus seen in 31.7% patients (52/164), at 3 months after stroke. FAB impairment alone, with MMSE in normal range, was seen in 28/52 (53.8%) patients. Memory was significantly more commonly affected in muti-infarct strokes as compared to single infarcts. Frontal executive dysfunction was not significantly different when single and multiple infarcts, or cortical and subcortical infarcts, were compared.

Aerobic exercise improves cognition and motor function poststroke

BACKGROUND

Cognitive deficits impede stroke recovery. Aerobic exercise (AEX) improves cognitive executive function (EF) processes in healthy individuals, although the learning benefits after stroke are unknown.

OBJECTIVE

To understand AEX-induced improvements in EF, motor learning, and mobility poststroke.

METHODS

Following cardiorespiratory testing, 38 chronic stroke survivors were randomized to 2 different groups that exercised 3 times a week (45-minute sessions) for 8 weeks. The AEX group (n = 19; 9 women; 10 men; 64.10 +/- 12.30 years) performed progressive resistive stationary bicycle training at 70% maximal heart rate, whereas the Stretching Exercise (SE) group (n = 19; 12 women; 7 men; 58.96 +/- 14.68 years) performed stretches at home. Between-group comparisons were performed on the change in performance at "Post" and "Retention" (8 weeks later) for neuropsychological and motor function measures.

RESULTS

VO(2)max significantly improved at Post with AEX (P = .04). AEX also improved motor learning in the less-affected hand, with large effect sizes (Cohen's d calculation). Specifically, AEX significantly improved information processing speed on the serial reaction time task (SRTT; ie, "procedural motor learning") compared with the SE group at Post (P = .024), but not at Retention. Also, at Post (P = .038), AEX significantly improved predictive force accuracy for a precision grip task requiring attention and conditional motor learning of visual cues. Ambulation and sit-to-stand transfers were significantly faster in the AEX group at Post (P = .038), with balance control significantly improved at Retention (P = .041). EF measurements were not significantly different for the AEX group.

CONCLUSION

AEX improved mobility and selected cognitive domains related to motor learning, which enhances sensorimotor control after stroke.

The number of patients with communication related impairments in acute hospital stroke units

Effective communication between patients who have had a stroke and their healthcare providers is vital. However, this may be difficult if patients have communication related impairments as a result of the stroke and/or have age related impairments that impact on their ability to communicate. This study sought to identify how many patients admitted into two acute hospital stroke units had a hearing, vision, speech, language and/or cognitive communicative impairment regardless of the cause. A total of 69 patients participated in this study. The majority (88%) of patients had one or more mild or more severe communication related impairments, 69% of patients had two or more communication related impairments and 39% of patients had three or more communication related impairments. The most common type of impairment was hearing impairment, followed by near vision impairment. That a high number of patients in acute hospital stroke units have communication related impairments suggests that many patients in acute stroke units may experience difficulty communicating their healthcare needs with healthcare providers and that alternative ways to support patients with communication related impairments in acute stroke units need to be available.

Enhanced cell death and learning deficits after a mini-stroke in aged hippocampus

One view of the etiology of age-related pathology is that a single genetic abnormality or some other single factor causes the disorder. An alternative view is that multiple combinations of factors produce variants of pathology. For example, the occurrence of stroke increases with age and has been linked to neurodegenerative disorders like Alzheimer's disease (AD). The current experiments test the hypothesis that a vascular insult and aging are co-factors that contribute to dementia by evaluating the neuronal and functional integrity of the hippocampus following small, localized strokes induced by the potent vasoconstrictor, endothelin-1 (ET-1) in the rat model of hippocampal aging. The neurotoxic effects of a low dose of ET-1 injected into the hippocampus measured by lesion size (volumetrics) and cell death (Fluorojade-B) were amplified in aged rats. The aged rats also showed hippocampal-dependent memory deficits that were not present in young rats. Overall, our pattern of results suggest that the aged hippocampus is more vulnerable to the same insult that has little or no effect on the young hippocampus.

Review: Recurrent stroke: where do we stand with the secondary prevention of noncardioembolic ischaemic strokes?

Strokes recur in 6—20% of the patients, most commonly within the first year; after a TIA or minor stroke; most recurrences will occur within the first 90 days. Our ability to identify patients at high risk is poor and most recurrent strokes cannot be explained by traditional risk factors. In 30—45% of the cases the second stroke will be of a different subtype. Moreover, patients are faced with other risks, like cardiac events and cognitive decline. With the population aging, the need for timely and effective secondary prevention strategies is more pressing than ever. This paper summarizes recent advances in pharmacological secondary prevention after a non-cardioembolic ischaemic stroke, and highlights critical questions still in need of answers.

The voice and laryngeal dysfunction in stroke: a report from the Neurolaryngology Subcommittee of the American Academy of Otolaryngology-Head and Neck Surgery

OBJECTIVE

Stroke is the third leading cause of death in the United States, behind heart disease and cancer. It affects as many as 5% of the population over 65 years old, and this number is growing annually due to the aging population. A significant portion of stroke patients that initially survive are faced with the risk of aspiration, as well as quality-of-life issues relating to impaired communication. The goal of this paper is to define the scope of practice in otolaryngology for these patients, and to review pertinent background literature.

STUDY DESIGN

Consensus report and retrospective literature review.

RESULTS

Otolaryngology involvement in these patients is critical to their rehabilitation, which often requires an interdisciplinary team of specialists. This committee presentation explores epidemiological data regarding the impact of stroke and its complications on hospitalizations. A pertinent review of neuroanatomy as it relates to laryngeal function is also discussed. State-of-the-art diagnostic and therapeutic procedures are presented.

CONCLUSION

There is a well-defined set of diagnostic and therapeutic options for laryngeal dysfunction in the stroke patient.

SIGNIFICANCE

Otolaryngologists play a critical role in the interdisciplinary rehabilitation team.

Metacognition in stroke: bedside assessment and relation to location, size, and stroke severity

BACKGROUND

Frontal syndromes are poorly represented on stroke scales, yet may constitute an important component of the neurologic deficit impacting treatment and rehabilitation efforts.

AIMS

To validate an assessment of a frontal network syndrome score (FNSS) in stroke and to ascertain the relationship of the FNSS to lesion location, volume, and severity in young people with stroke.

METHODS

Accrual through a cognitive stroke registry of young, alert, nonaphasic, nonencephalopathic, nonsubstance abuse prone people who were tested with the 16 domain FNSS within 4 weeks of their stroke. Lesion location was determined by the Cerefy 3-dimensional, digital, coxial brain atlas identifying 6 regions of cerebral interest. Lesion severity was assessed by the National Institute of Health Stroke Score and infarct volume was measured in cubic centimeters.

RESULTS

From a sample of 456 cases in the registry after exclusions of encephalopathy, depression, and aphasia, cases with frontal network syndrome encompassed 132 of 341 persons (39%). Of these patients (n=80) with mean age 45.7 years [confidence interval (CI): 43.4, 48.1], educational level 13.1 years (CI:12.5, 13.6), mean National Institute of Health Stroke Score of 3.3 (CI: 2.6, 4.0), and mean lesion volume 30.3 mL (CI: 13.7, 46.9), had full testing with the FNSS battery yielding sensitivity (93%), specificity (74%), positive predictive value (79%), negative predictive value (90%), and a good interrater reliability (kappa=0.89, P=0.001). Construct validity testing with 15 frontal neuropsychologic tests revealed good to excellent significant Pearson r values in 14 of 15 of the tests. There was no correlation (Pearson's) for lesion volume (r=0.07, P=0.52) but significant correlation with stroke severity (r=0.23, P=0.03). Analysis of variance testing of the FNSS revealed significant differences for all 6 domains without intergroup significant differences for frontal network syndrome domains in the stroke group.

CONCLUSIONS

The FNSS is a valid, practical measure of frontal syndromes in stroke. Frontal syndromes are common in young people with stroke and may be present no matter where the lesion, are not dependent on size of stroke and have a low correlation with stroke severity.

The validity of brief screening cognitive instruments in the diagnosis of cognitive impairment and dementia after first-ever stroke

INTRODUCTION

Brief cognitive tests such as the Mini-mental State Examination (MMSE) and the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) have been used to detect cognitive impairment and dementia in studies of stroke patients. However, there are few data on their validity for such use. We have evaluated their validity in detecting cognitive impairment not dementia (CIND) and dementia in a community-based sample of first-ever stroke patients.

METHODS

The standardized MMSE (S-MMSE) and the 16-item IQCODE were administered to 79 patients 1 year after a first-ever stroke. CIND and dementia were diagnosed independently using a comprehensive cognitive battery. The performances of the two tests were evaluated using receiver operating characteristic (ROC) analyses. Combined performance was evaluated when their scores were used in parallel (the "or rule"), in series (the "and rule") or as a weighted sum (the "weighted sum rule").

RESULTS

Both tests were extremely poor at detecting CIND individually and in combination. For dementia, at traditional cut-points, the S-MMSE (< or =23) was insensitive (0.50, 95% CI 0.16-0.84) and the IQCODE (> or =3.30) nonspecific (0.63, 95% CI 0.51-0.75). An acceptable balance between sensitivity and specificity was achieved for dementia using the "or rule" combination, but with only modest positive predictive value.

CONCLUSIONS

The S-MMSE and the IQCODE were individually poor at detecting CIND and dementia after a nonaphasic first-ever stroke. The combination was useful in detecting dementia but it does not replace the need for detailed neuropsychological tests.

Relation of apolipoprotein(a) size to alzheimer's disease and vascular dementia

Lipoprotein(a) [Lp(a)] level is a newly established vascular risk factor which has been suggested to play a role in dementia. However, the majority of Lp(a) cell-to-cell interactions are mediated by its specific apolipoprotein(a) [apo(a)] moiety. This suggests that the size polymorphism of apo(a) may be of importance in conveying the Lp(a)-related risk. Specifically, we postulated that variation in apo(a) isoform size may lead to increased risk of vascular dementia (VaD), Alzheimer's disease (AD), stroke, or all three of them. Under a case-control design we compared Lp(a) plasma levels and the distribution of apo(a) phenotypes in groups of subjects consisting of 50 VaD patients, 162 sporadic AD patients, 95 non-demented stroke patients (NDS), and 105 normal controls. The prevalence of small-sized apo(a) isoforms in the VaD group was significantly higher than that in the stroke and normal control groups, with an odds ratio of 5.29 (95% CI 2.24-12.49, p = 0.0001) for the development of VaD for individuals with at least one apo(a) isoform of low molecular weight (LMW). Furthermore, the possession of at least one small-sized apo(a) isoform significantly increased the risk of AD to 1.92 (95% CI 1.02-3.61, p = 0.0434). Our results demonstrate that possession of at least one LMW apo(a) isoform is significantly associated with dementia and specifically offer new evidence of a strong association between the lipoprotein system and post-stroke dementia.

Common carotid artery intima media thickness and post-stroke cognitive impairment

BACKGROUND AND PURPOSE

Acute stroke and other forms of cerebrovascular disease are well-recognized causes of cognitive impairment. Common carotid artery intima media thickness (CCA-IMT) has been associated with certain forms of cerebrovascular disease, but its association with cognitive impairment of vascular origin has not been elucidated. The purpose of this study was to investigate whether CCA-IMT is associated with cognitive impairment 1 year after an acute ischemic stroke.

METHODS

A total of 171 consecutive patients with the first ever stroke (mean age 66+/-11.5, 41% female) underwent carotid ultrasonography during hospitalization. Demographic data, vascular risk factors and presenting stroke features were also recorded. One year later, patients' cognitive performance and depression were assessed using the Mini-Mental State Examination (MMSE), and the Montgomery Asberg Depression Rating Scale (MADRS).

RESULTS

Cognitive impairment (MMSE score<24) was found in 67 (39%) of the 171 patients. CCA-IMT was significantly associated with cognitive impairment, and this association remained unchanged (OR 1.94; 95% CI 1.19-3.18) after adjustment for demographic data, vascular risk factors, stroke features, other carotid ultrasonography measurements and depression. Older age, low education level, large hemispheric lesions, hyperdense carotid plaques and depression were also independently associated with post-stroke cognitive impairment.

CONCLUSIONS

In this study, CCA-IMT was independently associated with cognitive impairment 1 year after an acute ischemic stroke, and thus, it might help with the screening of stroke patients at risk of cognitive impairment.

Prevention and treatment of stroke in patients with hypertension

BACKGROUND

Each year, stroke occurs in 30.9 million individuals worldwide and is responsible for approximately 4 million deaths. In the United States, it is the third leading cause of death, occurring with greater frequency than myocardial infarction in patients with hypertension. The greatest burden of stroke, apart from death, is serious long-term physical and mental disability. Stroke survivors often experience physical handicap, depression, and cognitive dysfunction, which together affect their daily functioning, quality of life, and survival. The treatment of stroke is associated with extremely high costs, with stroke-related illnesses responsible for >$49 billion in the United States in 2002. Despite intensive research efforts, few effective treatments are available once stroke has occurred; thus, stroke prevention should be a primary focus for all health care providers.

OBJECTIVE

The purpose of this article was to review the epidemiology and burden of stroke in terms of disability, quality of life, and cost of care, and to summarize the evidence for treatments having therapeutic benefit, with an emphasis on antihypertensive agents.

METHODS

Relevant studies were identified through a MEDLINE search of English-language articles published between 1990 and 2004. The search terms were stroke, epidemiology, economic impact, disability, quality of life, hypertension, drug therapy, and angiotensin II-receptor antagonists. Articles describing major clinical studies, new data, or new mechanisms pertinent to the therapy of stroke were selected for review.

CONCLUSIONS

Identifying and modifying key risk factors is crucial to reducing the morbidity and mortality of stroke. Hypertension is one of the most important risk factors for stroke, and treatment with a variety of antihypertensive agents reduces the risk. Recent evidence suggests that the angiotensin II (ATII)-receptor antagonist losartan may offer advantages beyond blood pressure lowering, including attenuation of the central aortic reflected pressure wave, molecule-specific properties, and neural protective influences on brain ATII type 2 receptors.

Transient ischaemic attacks are associated with increased rates of global cerebral atrophy

OBJECTIVES

To determine whether patients presenting with a first transient ischaemic attack (TIA) subsequently show increased rates of brain atrophy compared with age matched controls; and to assess potential risk factors for brain atrophy in this group.

METHODS

60 patients with a first, isolated TIA and 26 age and sex matched controls were recruited. None had evidence of cognitive impairment. Vascular risk factors were treated appropriately. All subjects had volumetric imaging at the start of the study and one year later, when they were clinically reassessed. TIA patients also had serial dual echo brain imaging. Rates of whole brain atrophy were calculated from the registered volumetric scans, as was the incidence of new ischaemic lesions. In the TIA group, the degree of white matter disease was assessed. Atrophy rates and blood pressure were compared between patients and controls.

RESULTS

22 patients (37%) developed new "clinically silent" infarcts during follow up. The mean (SD) annualised percentage atrophy rate in the TIA group was significantly higher than in the controls, at 0.82 (0.39)% v 0.33 (0.3)% (p < 0.0001). In the TIA group, diastolic blood pressure (p = 0.004) and white matter disease severity (p < 0.001) were correlated with cerebral atrophy rate. Increased white matter disease was found in patients in whom new ischaemic lesions developed (p < 0.001).

CONCLUSIONS

Patients presenting with a first TIA have excess global brain atrophy compared with age matched controls over the subsequent year. Increased atrophy rates following a TIA may be directly or indirectly related to increasing white matter disease and diastolic hypertension. Future studies should assess whether this atrophy inevitably leads to cognitive decline, and whether aggressive treatment of risk factors for cerebrovascular disease (particularly hypertension) after a TIA can influence outcome.