Deficits In Stroke Patients Research Articles

Unraveling the Influences of Hemodynamic Lag and Intrinsic Cerebrovascular Reactivity on Functional Metrics in Ischemic Stroke

Resting-state functional magnetic resonance imaging (rs-fMRI) is a prominent tool for investigating functional deficits in stroke patients. However, the extent to which the hemodynamic lags (LAG) and the intrinsic cerebrovascular reactivity (iCVR) may affect the rs-fMRI metrics in different scales needs to be clarified for ischemic stroke. In this study, 73 ischemic stroke patients and 74 healthy controls (HC) were recruited to investigate how the correction of the LAG and/or iCVR would influence resting-state functional magnetic resonance imaging (rs-fMRI) metrics of three different spatial scales (local-scale, meso-scale and global-scale) in ischemic stroke. The analysis revealed that the Stroke pattern of all functional metrics using different correction strategies resembled the HC pattern. The highest overlap was observed in the Stroke pattern with correction for both LAG and iCVR, while the pattern without correction showed the lowest overlap. Most functional metrics after correction showed higher sensitivity in detecting between-group differences than those without correction. Moreover, our results were generally reproducible in an independent dataset. Collectively, these findings emphasize the necessity of considering LAG and iCVR effects to investigate stroke-related functional alterations, and highlight the significance of correction strategies for accurately interpreting the findings in rs-fMRI study of ischemic stroke.

The Turkish version of the cognitive assessment scale for stroke patients (CASP-TR): a reliability and validity

ABSTRACT Background Stroke, a prevalent neurological condition globally, is associated with a high mortality and often affects cognitive function. The Cognitive Assessment Scale for Stroke Patients (CASP) was developed to quickly identify and measure primary cognitive deficits, focusing particularly on stroke survivors. Within the Turkish context, there is a limited availability of validated cognitive screening tests for use after stroke. Aims The study aimed to translate CASP into Turkish (CASP-TR) and validate it in stroke patients. Methods and procedures After the translation of the CASP items into culturally appropriate Turkish versions, a pilot testing of the pre-final version was administered to post-stroke patients and healthy controls by two raters. Following completion of the final version of CASP-TR, 40 stroke patients were consecutively enrolled in validation process. Three blinded raters conducted all assessments with intervals of 1- or 2 days between evaluation sessions. The accuracy of CASP-TR was assessed using sensitivity, specificity, predictive values, likelihood ratios, and area under curve. CASP-TR performance in post-stroke patients with and without cognitive dysfunction was compared using the Mini-Mental State Examination (MMSE). CASP-TR data obtained by two raters were compared based on the presence of aphasia. Outcomes and results The study assessed inter-rater agreement using intraclass correlation coefficient (ICC), yielding a score of 0.92 (95% CI 0.85–0.96) between raters. Across subtests, moderate to good agreement was observed in most domains. Correlation analyses showed a strong positive relationship (r = 0.80) between mean CASP-TR and MMSE scores. CASP-TR and MMSE scores were stratified based on the presence of aphasia. CASP-TR scores from both raters were notably lower in the aphasia group compared to the non-aphasia group (p < 0.001). Similarly, MMSE scores were significantly lower in the aphasia group (p < 0.001). The patients were also classified into cognitive dysfunction and non-cognitive dysfunction groups based on MMSE scores. No statistically significant score differences were found between examiners in the cognitive dysfunction group (p = 0.267) or non-cognitive dysfunction group (p = 0.156) (p > 0.05). CASP-TR demonstrated a sensitivity of 82.4%, specificity of 78.6%, positive predictive value of 87.5%, negative predictive value of 68.7%, a positive likelihood ratio of 3.77, a negative likelihood ratio of 0.25, and an area under curve of 0.88. Conclusions This study proposes that CASP-TR is a valuable cognitive screening tool for assessing cognitive deficits in stroke patients, and it also demonstrates sensitivity to cognitive deficits in stroke patients with aphasia. The thorough validation within the acute post-stroke Turkish population demonstrates remarkably good accuracy and very good Area Under Curve (AUC) values.

Validation of the abbreviated version of the Token Test in Latin American Spanish stroke patients.

The abbreviated version of the Token Test (aTT) is widely used to assess language comprehension deficits in stroke patients (SPs). However, aTT has not been validated for Latin American Spanish speakers, so clinicians tend to use cut-off scores for aTT validated in developed countries. To provide normative data for the Spanish aTT (Sp-aTT) in healthy Chilean Spanish-speaking and SP, determining the influence of sociodemographic variables such as gender, age and education on Sp-aTT performance. A total of 210 healthy volunteers (age range = 18-88 years) and 197 SPs (age range = 23-94 years), all native speakers of Chilean Spanish, were recruited. The association of age, gender and years of education on the Sp-aTT performance was analysed. Specificity and sensibility analyses of the Sp-aTT to diagnose language comprehension deficits were completed. Only age (p < 0.001) and years of education (p < 0.001) impacted the total score of Sp-aTT. Gender did not show an association with Sp-aTT performance (p = 0.181). For SPs, the Sp-aTT score showed a significant positive correlation (rho = 0.4, p < 0.001) with the aphasia severity rating scale (ASRS) score. For Sp-aTT, the area under the curve was 0.97, and the optimal cut-off score for the Sp-aTT was 30 (0.73 of sensitivity, 0.92 of specificity and a Youden index of 0.644). Age and years of education are two key factors to be controlled for when determining the optimal cut-off points for the Sp-aTT. Our results also highlight the need for language-specific norms in stroke and aphasia research. What is already known on the subject The aTT has been validated and adapted in several countries. Its properties in screening and detecting comprehensive deficits in SPs highlight its potential as a screening tool in clinical practice. Moreover, considering that stroke is the third largest cause of death worldwide, research and clinical practice have focused on how to improve early detection of deficits in these people, especially those related to cognition, language and functionality in SPs. Therefore, counting with validated and adapted tools is essential for clinicians because it could contribute to accurate intervention and classification of language disorders. What this paper adds to the existing knowledge The main contribution of this study is to provide normative data for the aTT in Latin American Spanish speakers. No previous studies have focused on validating this test and analysing the influence of three critical variables (age, gender and years of education) on its performance in SPs from Latin America. In addition, we propose a classification of the severity of comprehension deficits in SPs. Finally, we found comprehension deficits in patients with right and left hemisphere stroke, which would imply that these deficits would not be exclusive to left hemisphere stroke. What are the potential or actual clinical implications of this work? Contribute with validation of language comprehension tools, such as the aTT, could improve early diagnosis of patients with language disorders. This validation provides a test based on the sociodemographic characteristics of Latin American Speakers, which has yet to be established. Due to this, normative data considering the sociodemographic characteristics of the target population is crucial for accurately classifying comprehension deficits after brain damage.

Targeting post-stroke neuroinflammation with Salvianolic acid A: molecular mechanisms and preclinical evidence.

Salvianolic acid A (SalA), a bioactive compound extracted from Salvia miltiorrhiza, has garnered considerable interest for its potential in ameliorating the post-stroke neuroinflammation. This review delineates the possible molecular underpinnings of anti-inflammatory and neuroprotective roles of SalA, offering a comprehensive analysis of its therapeutic efficacy in preclinical studies of ischemic stroke. We explore the intricate interplay between post-stroke neuroinflammation and the modulatory effects of SalA on pro-inflammatory cytokines, inflammatory signaling pathways, the peripheral immune cell infiltration through blood-brain barrier disruption, and endothelial cell function. The pharmacokinetic profiles of SalA in the context of stroke, characterized by enhanced cerebral penetration post-ischemia, makes it particularly suitable as a therapeutic agent. Preliminary clinical findings have demonstrated that salvianolic acids (SA) has a positive impact on cerebral perfusion and neurological deficits in stroke patients, warranting further investigation. This review emphasizes SalA as a potential anti-inflammatory agent for the advancement of innovative therapeutic approaches in the treatment of ischemic stroke.

Efficacy of personalized rTMS to enhance upper limb function in subacute stroke patients: a protocol for a multi-center, randomized controlled study.

Repetitive transcranial magnetic stimulation (rTMS) is widely used therapy to enhance motor deficit in stroke patients. To date, rTMS protocols used in stroke patients are relatively unified. However, as the pathophysiology of stroke is diverse and individual functional deficits are distinctive, more precise application of rTMS is warranted. Therefore, the objective of this study was to determine the effects of personalized protocols of rTMS therapy based on the functional reserve of each stroke patient in subacute phase. This study will recruit 120 patients with stroke in subacute phase suffering from the upper extremity motor impairment, from five different hospitals in Korea. The participants will be allocated into three different study conditions based on the functional reserve of each participant, measured by the results of TMS-induced motor evoked potentials (MEPs), and brain MRI with diffusion tensor imaging (DTI) evaluations. The participants of the intervention-group in the three study conditions will receive different protocols of rTMS intervention, a total of 10 sessions for 2 weeks: high-frequency rTMS on ipsilesional primary motor cortex (M1), high-frequency rTMS on ipsilesional ventral premotor cortex, and high-frequency rTMS on contralesional M1. The participants of the control-group in all three study conditions will receive the same rTMS protocol: low-frequency rTMS on contralesional M1. For outcome measures, the following assessments will be performed at baseline (T0), during-intervention (T1), post-intervention (T2), and follow-up (T3) periods: Fugl-Meyer Assessment (FMA), Box-and-block test, Action Research Arm Test, Jebsen-Taylor hand function test, hand grip strength, Functional Ambulatory Category, fractional anisotropy measured by the DTI, and brain network connectivity obtained from MRI. The primary outcome will be the difference of upper limb function, as measured by FMA from T0 to T2. The secondary outcomes will be the differences of other assessments. This study will determine the effects of applying different protocols of rTMS therapy based on the functional reserve of each patient. In addition, this methodology may prove to be more efficient than conventional rTMS protocols. Therefore, effective personalized application of rTMS to stroke patients can be achieved based on their severity, predicted mechanism of motor recovery, or functional reserves. https://clinicaltrials.gov/, identifier NCT06270238.

Predicting functional impairments with lesion-derived disconnectome mapping: Validation in stroke patients with motor deficits.

Focal structural damage to white matter tracts can result in functional deficits in stroke patients. Traditional voxel-based lesion-symptom mapping is commonly used to localize brain structures linked to neurological deficits. Emerging evidence suggests that the impact of structural focal damage may extend beyond immediate lesion sites. In this study, we present a disconnectome mapping approach based on support vector regression (SVR) to identify brain structures and white matter pathways associated with functional deficits in stroke patients. For clinical validation, we utilized imaging data from 340 stroke patients exhibiting motor deficits. A disconnectome map was initially derived from lesions for each patient. Bootstrap sampling was then employed to balance the sample size between a minority group of patients exhibiting right or left motor deficits and those without deficits. Subsequently, SVR analysis was used to identify voxels associated with motor deficits (p < .005). Our disconnectome-based analysis significantly outperformed alternative lesion-symptom approaches in identifying major white matter pathways within the corticospinal tracts associated with upper-lower limb motor deficits. Bootstrapping significantly increased the sensitivity (80%-87%) for identifying patients with motor deficits, with a minimum lesion size of 32 and 235 mm3 for the right and left motor deficit, respectively. Overall, the lesion-based methods achieved lower sensitivities compared with those based on disconnection maps. The primary contribution of our approach lies in introducing a bootstrapped disconnectome-based mapping approach to identify lesion-derived white matter disconnections associated with functional deficits, particularly efficient in handling imbalanced data.

Effort-based decision making and motivational deficits in stroke patients

Motivational deficits in patients recovering from stroke are common and can reduce active participation in rehabilitation and thereby impede functional recovery. We investigated whether stroke patients with clinically reduced drive, initiation, and endurance during functional rehabilitative training (n = 30) display systematic alterations in effort-based decision making compared to age, sex, and severity-matched stroke patients (n = 30) whose drive appeared unaffected. Notably, the two groups did not differ in self-reported ratings of apathy and depression. However, on an effort-based decision-making task, stroke patients with clinically apparent drive impairment showed intact willingness to accept effort for reward, but were more likely to fail to execute the required effort compared to patients without apparent drive impairments. In other words, the decision behavioural assessment revealed that stroke patients that displayed reduced drive, initiation, and endurance during inpatient neurorehabilitation failed to persist in goal-directed effort production, even over very short periods. These findings indicate that reduced drive during rehabilitative therapy in post-stroke patients is not due to a diminished motivation to invest physical effort, but instead is related to a reduced persistence with effortful behaviour.

Dynamic brain activity states of memory impairment in stroke patients with varying motor outcomes.

The objective of this study was to characterize the alteration patterns of dynamic spatiotemporal activity in chronic subcortical stroke patients with varying motor outcomes, while investigating the imaging indicators relevant to the assessment of potential cognitive deficits in these patients. A total of 136 patients and 88 normal controls were included in the analysis of static and dynamic intrinsic brain activity, determined by amplitude of low-frequency fluctuations. The findings unveiled that subcortical stroke patients exhibited significantly aberrant temporal dynamics of intrinsic brain activity, involving regions within multiple brain networks. These spatiotemporal patterns were found to be contingent upon the side of the lesion. In addition, these aberrant metrics demonstrated potential in discerning cognitive deficits in stroke patients with memory impairment, with the dynamic indices exerting more influence than the static ones. The observe findings may indicate that subcortical stroke can trigger imbalances in the segregation and integration of spatiotemporal patterns across the entire brain with multi-domain networks, especially in patients with poor motor outcomes. It suggests that the temporal dynamics indices of intrinsic brain activity could serve as potential imaging indicators for assessing cognitive impairment in patients with chronic subcortical stroke, which may be associated with the motor outcomes.

Prediction of behavioral deficits in acute stroke from lesion and structural disconnection mapping.

Prediction of behavioral deficits in stroke relies on understanding the distribution of focal damage as well as the distribution of the underlying functional anatomy. Using structural or functional magnetic resonance imaging, previous studies investigated the predictive performance of imaging biomarkers for behavioral deficits in stroke patients. However, only focal lesion information or functional connectivity information alone was used in the modelling, with a small sample size and on a specific behavioral deficit domain. In this study, we investigated the prediction of behavioral deficits in acute stroke using both focal lesion patterns and structural disconnection mapping on a cohort of 551 ischemic stroke patients within one week post symptom onset. Five behavioral deficits domains, including motor, cognitive, visual, somatosensory and coordination deficits, were investigated. A probabilistic map of lesion-induced structural "disconnectome" map was created to estimate the degree of structural disconnection due to lesions. In the predictive modelling, both lesion volume and location and distant structural disconnections were included in combination with the clinical information. The results showed that improved prediction performance was achieved when considering both focal lesion patterns and global lesion-induced structural disconnections for all five behavioral deficits groups. Distinct lesion maps were obtained for each behavioral deficit, providing insights into neurobiological mechanisms of stroke functional impairment.

Aberrant dynamic Functional-Structural connectivity coupling of Large-scale brain networks in poststroke motor dysfunction

Background and purposeStroke may lead to widespread functional and structural reorganization in the brain. Several studies have reported a potential correlation between functional network changes and structural network changes after stroke. However, it is unclear how functional-structural relationships change dynamically over the course of one resting-state fMRI scan in patients following a stroke; furthermore, we know little about their relationships with the severity of motor dysfunction. Therefore, this study aimed to investigate dynamic functional and structural connectivity (FC-SC) coupling and its relationship with motor function in subcortical stroke from the perspective of network dynamics. MethodsResting-state functional magnetic resonance imaging and diffusion tensor imaging were obtained from 39 S patients (19 severe and 20 moderate) and 22 healthy controls (HCs). Brain structural networks were constructed by tracking fiber tracts in diffusion tensor imaging, and structural network topology metrics were calculated using a graph-theoretic approach. Independent component analysis, the sliding window method, and k-means clustering were used to calculate dynamic functional connectivity and to estimate different dynamic connectivity states. The temporal patterns and intergroup differences of FC-SC coupling were analyzed within each state. We also calculated dynamic FC-SC coupling and its relationship with functional network efficiency. In addition, the correlation between FC-SC coupling and the Fugl-Meyer assessment scale was analyzed. ResultsFor SC, stroke patients showed lower global efficiency than HCs (all P < 0.05), and severely affected patients had a higher characteristic path length (P = 0.003). For FC and FC-SC coupling, stroke patients predominantly showed lower local efficiency and reduced FC-SC coupling than HCs in state 2 (all P < 0.05). Furthermore, severely affected patients also showed lower local efficiency (P = 0.031) and reduced FC-SC coupling (P = 0.043) in state 3, which was markedly linked to the severity of motor dysfunction after stroke. In addition, FC-SC coupling was correlated with functional network efficiency in state 2 in moderately affected patients (r = 0.631, P = 0.004) but not significantly in severely affected patients. ConclusionsStroke patients show abnormal dynamic FC-SC coupling characteristics, especially in individuals with severe injuries. These findings may contribute to a better understanding of the anatomical functional interactions underlying motor deficits in stroke patients and provide useful information for personalized rehabilitation strategies.

Risk factors and predictors of acute gastrointestinal injury in stroke patients

PurposeThis prospective study investigates the incidence, risk factors, biological markers, and predictors of acute gastrointestinal injury (AGI) in patients with stroke. MethodsThe study involved a total of 98 patients with acute cerebrovascular disease were included. According to the ESICM, the definition of AGI in intensive care patients is classified as grade 0, I, II and III. Patients’ demographics, serological indicators (e.g., urea nitrogen, albumin, D-lactate, α-GST, neutrophil count and lymphocyte count), relevant scores (NIHSS score, GCS score, APACHE II score), length of hospital stay as well as the 7-day and 28-day mortality were recorded. ResultsIn 98 patients, the incidence of AGI was 90.8 %. The APACHE II, NIHSS, GCS and Hs-mGPS scores significantly increased the odds of a higher AGI grade (P < 0.05). Also, current use of antibiotics and the presence of pneumonia significantly increased the probability of a higher AGI grade (P < 0.05). NLR, diabetes and dehydrating drugs increased the probability of AGI grade II and III (P < 0.05). Finally, an early commencement of endovascular treatment significantly reduced the incidence of AGI class III (P < 0.05). Patients with higher AGI grades had longer hospital stays and higher 28-day mortality (P < 0.05). ConclusionThe degree of the neurological deficit in stroke patients (high NIHSS score, low GCS score) in this study was associated with the development of AGI. The patients' gastrointestinal barrier function continued to deteriorate during the week of onset. The APACHE II score, NRL score and HS-mGPS score have some predictive value for the occurrence of AGI in stroke patients.

Short term effects of anodal cerebellar vs. anodal cerebral transcranial direct current stimulation in stroke patients, a randomized control trial.

Balance and gait impairments are major motor deficits in stroke patients that require intensive neuro-rehabilitation. Anodal transcranial direct current stimulation is a neuro-modulatory technique recently used in stroke patients for balance and gait improvement. Majority of studies focusing on tDCS have assessed its effects on cerebral motor cortex and more recently cerebellum as well but to our best knowledge the comparison of stimulating these two regions in stroke patients is not investigated so far. The current study aimed to compare the effect of anodal transcranial direct current stimulation on cerebellar and cerebral motor cortex M1 in stroke patients. This double-blinded, parallel, randomized, sham controlled trial included 66 patients with a first-ever ischemic stroke were recruited into three groups; Cerebellar stimulation group (CbSG), M1 Stimulation Group (MSG), and Sham stimulation group (SSG). A total of three sessions of anodal transcranial direct current stimulation were given on consecutive days in addition to non-immersive virtual reality using Xbox 360 with kinect. Anodal tDCS with an intensity of 2 mA was applied for a duration of 20 min. Primary outcome measures berg balance scale (BBS), timed up and go test (TUG), BESTest Balance Evaluation-Systems Test (BESTest) and secondary outcomes measures montreal cognitive assessment (MoCA), mini mental state examination (MMSE), Johns Hopkins Fall Risk Assessment Tool (JHFRAT), twenty five feet walk test (25FWT), six minute walk test (6MWT), and tDCS Adverse Effects was assessed before initiation of treatment (T0) and at the end of third session of stimulation (T1). The results of between group's analysis using mean difference showed a significant difference with p-value <0.05 for balance (BBS, TUG, BESTest), walking ability (6MWT, 25FWT), risk of fall (JHFRAT). Cognitive function did not show any significant change among the groups for MoCA with p-value >0.05 but MMSE was improved having significant p-value (p = 0.013). However, 6MWT and 25FWT showed non-significant results for both between group and within group analysis. In pairwise comparison both the cerebellar and cerebral stimulation groups showed Significant difference with p-value <0.05 in comparison to sham stimulation; BBS (cerebellar vs. sham p ≤ 0.001, cerebral vs. sham p = 0.011), TUG (cerebellar vs. sham p = 0.001, cerebral vs. sham p = 0.041), Bestest (cerebellar vs. sham p = 0.007, cerebral vs. sham p = 0.003). Whereas for JHFRAT only cerebellar stimulation in comparison to sham and motor cortex stimulation showed significant improvements (cerebellar vs. M1 p = 0.037, cerebellar vs. sham p = 0.037). MMSE showed significant improvement in M1 stimulation (M1 vs. cerebellar p = 0.036, M1 vs. sham p = 0.011). Findings of the study suggest anodal tDCS stimulation of the cerebellum and cerebral motor cortex both improves gait, balance and risk of fall in stroke patients. However, both stimulation sites do not induce any notable improvement in cognitive function. Effects of both stimulation sites have similar effects on mobility in stroke patients.

Evaluation of Gait Smoothness in Patients with Stroke Undergoing Rehabilitation: Comparison between Two Metrics.

The use of quantitative methods to analyze the loss in gait smoothness, an increase in movement intermittency which is a distinguishing hallmark of motor deficits in stroke patients, has gained considerable attention in recent years. In the literature, the spectral arc length (SPARC), as well as metrics based on the measurement of the jerk, such as the log dimensionless jerk (LDLJ), are currently employed to assess smoothness. However, the optimal measure for evaluating the smoothness of walking in stroke patients remains unknown. Here, we investigated the smoothness of the body’s center of mass (BCoM) trajectory during gait, using an optoelectronic system, in twenty-two subacute and eight chronic patients before and after a two-month rehabilitation program. The two measures were evaluated for their discriminant validity (ability to differentiate the smoothness of the BCoM trajectory calculated on the cycle of the affected and unaffected limb, and between subacute and chronic patients), validity (correlation with clinical scales), and responsiveness to the intervention. According to our findings, the LDLJ outperformed the SPARC in terms of the examined qualities. Based on data gathered using an optoelectronic system, we recommend using the LDLJ rather than the SPARC to investigate the gait smoothness of stroke patients.

Transcranial alternating brain stimulation at alpha frequency reduces hemispatial neglect symptoms in stroke patients

Background/ObjectiveNon-invasive brain stimulation techniques such as transcranial alternating current stimulation (tACS) may help alleviate attention deficits in stroke patients with hemispatial neglect by modulating oscillatory brain activity. We applied high-definition (HD)-tACS at alpha frequency over the contralesional hemisphere to support unilateral oscillatory alpha activity and correct for the pathologically altered attention bias in neglect patients. MethodsWe performed a within-subject, placebo-controlled study in which sixteen stroke patients with hemispatial neglect underwent 10 Hz (alpha) as well as sham (placebo) stimulation targeting the contralesional posterior parietal cortex. Attentional bias was measured with a computerized visual detection paradigm and two standard paper-and-pencil neglect tests. ResultsWe revealed a significant shift of attentional resources after alpha-HD-tACS, but not sham tACS, toward the ipsilateral and thus contralesional hemifield leading to a reduction in neglect symptoms, measured with a computerized visual detection paradigm and a widely used standard paper and pencil neglect tests. ConclusionsWe showed a significant alpha-HD-tACS-induced shift of attentional resources toward the contralesional hemifield, thus leading to a reduction in neglect symptoms. Importantly, HD-tACS effects persisted after the stimulation itself had ended. This tACS protocol, based on intrinsic oscillatory processes, may be an effective and well-tolerated treatment option for neglect.

P 24 Domain-general deficits after stroke lesions in the dorsal and ventral processing stream of the left hemisphere

Question: Stroke in the left hemisphere leads to deficits in language, motor cognition, and spatial attention; hereby an isolated lesion can result in deficits in multiple domains. The dual-loop model of a dorsal and ventral processing stream (Weiller, 2011) can serve as a functional-anatomic framework for task-specific but cross-domain processing. In this study, we will examine the shared variance of deficits in all three domains following a single stroke lesion to identify behavioural clusters of deficits and the associated lesion locations. Methods: In a prospective study, 165 patients (age 64.4±14.3 years) with first-ever left hemispheric stroke in the acute phase (4.79±2.08 days after symptom onset) were assessed for deficits in language (token test), motor cognition (meaningless imitation, pantomime, tool use) and spatial attention deficits (extinction, neglect). Common variance was extracted using rotated principal component analysis with oblimin rotation (PCA). Multivariate support-vector-regression lesion-symptom-mapping (SVR-LSM) based on magnetic tomography images was used to assign behavioral clusters and lesions. Results: PCA revealed two components: the first component (54.9% variance explained) included the token test, motor cognition (mainly pantomime and tool use), and neglect. It represents conceptual, semantic, and time-independent processing of information. The second component (further 10.9% variance explained) was associated with meaningless imitation, other apraxia tasks, and extinction and represents time- and space-dependent processing. In the SVR-LSM, the first component was associated with lesions in the superior/middle temporal gyrus and inferior/middle frontal lobe while the second component was related to a lesion cluster in the superior/inferior parietal lobe. Discussion: Behavioral data suggest domain-general cognitive processes (time- and-space dependent vs. conceptual, semantic, time-independent) in the left hemisphere - impairment of those leads to a specific pattern of deficits across all cognitive domains. Lesions to parietal regions of the dorsal stream led to impairment of time- and space dependent processing; impaired conceptual, semantic, and time-independent processing was related to lesions in the frontal and temporal lobe, including regions of the ventral stream. There results extend our understanding of the multidimensionality of cognitive deficits in stroke patients, which should have impact on their rehabilitative treatment. References Weiller, C., Bormann, T., Saur, D., Musso, M., & Rijntjes, M. (2011). How the ventral pathway got lost – And what its recovery might mean. Brain and Language , 118 (1–2), 29–39. https://doi.org/10.1016/j.bandl.2011.01.005 .

Minocycline improves learning and memory functions in ischemic stroke rats via reduction of cerebral ischemia-induced neuroinflammation and apoptosis

&#x0D; &#x0D; &#x0D; &#x0D; Purpose: To study the effect minocycline on learning and memory functions in ischemic stroke rats, and the underlying mechanism.&#x0D; Methods: 60 adult male SD rats were randomly divided into control group, ischemic brain damage (6 and 24 h MACO) groups; and 6 and 24 h minocycline groups, with 12 rats in each group. The volume of cerebral infarction, neuronal cell apoptosis, NF-κB protein expression, learning and memory ability, and the number of Iba-1+CD206-positive cells, and CD206/CD68 mRNA expressions in sham group, 6 h MACO group and 6 h minocycline group were determined and compared.&#x0D; Results: The number of iba-1 +CD206-positive cells, expression level of CD206 mRNA, frequency of platform crossing, and percentage of third quadrant route in 6 h minocycline group were significantly higher than the corresponding values in 6 h MACO group. However, the cerebral infarction volume, number of Nini-positive cells, and the NF- B protein expression levels were markedly reduced, relative to corresponding values in 6 h MACO rats. The number of iba-1+CD206-positive cells was significantly lower in 6 h MACO rats than in sham rats, while the expression level of CD68 mRNA was significantly higher (p &lt; 0.05). The number of TUNEL-positive cells in 6 and 24 h minocycline groups were markedly lower than that in 6 h MACO group (p &lt; 0.05).&#x0D; Conclusion: Minocycline improves learning and memory of ischemic stroke rats by relieving the neuroinflammation induced by cerebral ischemia and cell apoptosis. Thus, the compound can be further developed for management learning and memory deficits in stroke patients.&#x0D; &#x0D; &#x0D; &#x0D;

Multisensory Integration in Stroke Patients: A Theoretical Approach to Reinterpret Upper-Limb Proprioceptive Deficits and Visual Compensation.

For reaching and grasping, as well as for manipulating objects, optimal hand motor control arises from the integration of multiple sources of sensory information, such as proprioception and vision. For this reason, proprioceptive deficits often observed in stroke patients have a significant impact on the integrity of motor functions. The present targeted review attempts to reanalyze previous findings about proprioceptive upper-limb deficits in stroke patients, as well as their ability to compensate for these deficits using vision. Our theoretical approach is based on two concepts: first, the description of multi-sensory integration using statistical optimization models; second, on the insight that sensory information is not only encoded in the reference frame of origin (e.g., retinal and joint space for vision and proprioception, respectively), but also in higher-order sensory spaces. Combining these two concepts within a single framework appears to account for the heterogeneity of experimental findings reported in the literature. The present analysis suggests that functional upper limb post-stroke deficits could not only be due to an impairment of the proprioceptive system per se, but also due to deficiencies of cross-references processing; that is of the ability to encode proprioceptive information in a non-joint space. The distinction between purely proprioceptive or cross-reference-related deficits can account for two experimental observations: first, one and the same patient can perform differently depending on specific proprioceptive assessments; and a given behavioral assessment results in large variability across patients. The distinction between sensory and cross-reference deficits is also supported by a targeted literature review on the relation between cerebral structure and proprioceptive function. This theoretical framework has the potential to lead to a new stratification of patients with proprioceptive deficits, and may offer a novel approach to post-stroke rehabilitation.

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.

Correlation of Diffusion-Weighted Magnetic Resonance Imaging Determined Infarct Volume with Clinically Assessed National Institutes of Health Stroke Scale in Patients of Acute Stroke: A Cross-sectional Study

Introduction: Infarct volume is an essential factor in predicting patient prognosis. National Institutes of Health Stroke Scale (NIHS) allows consistent reporting of neurological deficits in stroke patients. Limited studies have been done in the Indian population correlating the volume of infarct and the NIHS Scale. Aim: To correlate the Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) assessed infarct volume with the clinically assessed NIHS to prognosticate clinical outcomes in patients of acute stroke. Materials and Methods: This was a cross-sectional study comprising 36 patients of acute stroke with a study duration from November 2017 to April 2019. Diffusion-Weighted MRI was obtained on Siemens Magnetom 3 Tesla, and diffusion restriction on b=1000 image was measured with a Region of Interest (ROI) tool using manual contouring in each slice. Assessment of the neurological deficit was done by NIHS scale at the time of admission and 7 days post admission for each patient. Correlation of the infarct volume with NIHS Scale was done with p&lt;0.05 considered statistically significant. Receiver Operating Characteristic Curve (ROC) was used to predict cut-off of the volume of infarct and NIHS Scale to predict adverse patient outcome. Results: Present study consisted of 36 patients of acute stroke with a mean age of 52.05±18.53 years. The minimum age of the patient was one year, and the maximum age was 78 years. There was a statistically significant correlation between the volume of infarct and NIHS Scale at time of admission admission (p=0.001; r=0.807) and the NIHS Scale at one week (p=0.002; r=0.602).The Area Under the Curve (AUC) for a cut-off of 115 cc of the volume of infarct in predicting adverse patient outcomes was 0.931, whereas that for the NIHS scale of 20 was 0.998. Conclusion: Volume of infarct of 115 cc and NIHS Scale of 20 are excellent as prognostic tools in predicting patient outcome and have comparable efficacy.

Bedside Assessment of Vergence in Stroke Patients.

Given the widely distributed network of midbrain, pontine, cerebellar, and cortical areas involved in the neural control of vergence, one might expect various vergence deficits in stroke patients. In this article, we investigated the localizing value of bedside vergence testing with respect to different supratentorial and infratentorial infarction locations. Three hundred five stroke patients and 50 age-matched controls were examined prospectively by means of bedside tests to assess slow and fast binocular (i.e., symmetrical) as well as slow and fast monocular (i.e., asymmetrical) convergence. Infarction locations, as identified on MRI, were correlated with vergence performance using multinomial logistic regression. Vergence deteriorated with age in both stroke patients and healthy controls. Most infarction locations did not show significant associations with vergence parameters, apart from cases with parietal lobe lesions, which exhibited insufficient asymmetrical, slow and fast vergence for both the left and the right eye. Finally, patients with severe ischemic small vessel disease showed a slight but significant decrease in their fast binocular vergence performance. There is only a limited localizing value of vergence deficits in stroke. Parietal lobe infarctions are more frequently associated with insufficient binocular and monocular vergence. Midbrain strokes were too few to draw final conclusions. However the most robust factor to emerge from our data is age. Older subjects show poor slow binocular as well as slow and fast monocular vergence. Extended white matter lesions are also correlated with deficient vergence ability suggesting a role for subcortical wide range connections in maintaining an intact vergence circuitry.