Cerebral microinfarcts disruption of remote cortical thickness.

INTRODUCTION: Cerebral microinfarcts (CMI) are common lesions, carrying an important contribution to small-vessel-related cognitive impairment. CMIs were previously found to cause local microstructural damage and disruption of white matter integrity. This study examines CMIs influence on cortical thickness in remote brain areas. METHODS: Six small silent diffuse weighted imaging (DWI) lesions corresponding to subacute CMI were identified among five patients who underwent baseline and follow-up MRI scans from the Tel-Aviv Acute Brain Stroke Cohort (TABASCO). Regions of interest (ROIs) corresponding to the site of the DWI lesions and of the non-lesioned contralateral hemisphere (control ROI) were co-registered. DTI tractography was additionally performed to reconstruct the white matter tracts containing the ROIs. The normalized cortical thickness was calculated for the DWI lesional tract as well as for the contralateral non-lesional tract, and the lesion-to-control cortical thickness ratio (CTR) was calculated. RESULTS: Post-lesional scans, performed 25.1 ± 1.2 months after CMI detection, demonstrated reduced mean CTR within the ROI from 1.8 to 1.1 (p = 0.032). There was no difference between the CTR of the right hemisphere relative to those on the left hemisphere, or between the CTR change of the cortical and non-cortical CMI. DISCUSSION: This study demonstrated the prolonged influence of CMI on cortical thickness in remote ROI. The total number of CMIs is difficult to determine, however it has been shown that detecting even a single CMI suggests the existence of hundreds to thousands lesions. Therefore, the cumulative impact of these widely distributed lesions on cerebral cortex may have a significant contribution to the development of vascular cognitive impairment.

Clinical and radiological determinants of transient symptoms associated with infarction (TSI).

BACKGROUND: The definition of transient ischemic attack was traditionally based on clinical features only. The wide use of magnetic resonance imaging (MRI) led to the definition of a new entity - transient symptoms associated with infarction (TSI). It is unclear why patients with similar radiological infarctions may have different clinical manifestation - ranging from complete symptoms resolution to major neurological sequelae. We sought to determine which factors differentiate acute diffuse weighted imaging (DWI) lesion presentation - stroke versus TSI. METHODS: 282 Participants, recruited for the Tel-Aviv Brain Acute Stroke Cohort study (TABASCO), were enrolled consecutively. Participants underwent extensive cognitive evaluation, wide laboratory tests and brain MRI scans evaluated for cerebral small vessel disease (SVD) biomarkers, according to the STRIVE protocol. Demographic and clinical characteristics were also examined. RESULTS: A total of 239 patients had stroke and 43 patients had TSI. TSI patients had smaller average lesion volume (0.77 cm3 versus 2.64 cm3, p = 0.002). Lesion location did not differentiate TSI and stroke. Stroke patients had elevated inflammatory markers, unrelated to lesion size (CRP 4.2 mg/L versus 1.7 mg/L, p = 0.011). TSI patients had better global cognitive score and MoCA score at admission and 24 months following the index event (p < 0.001). TSI patients also had better Berg balance score (p = 0.004). No significant association was found with MRI SVD markers. CONCLUSIONS: Lesion size, but not location, differentiates TSI and stroke, especially at a cutoff value of 10 cm3. Elevated inflammatory response was linked to worse course independently of lesion volume. Cognitive and high function tests are associated to the clinical phenotype of ischemic lesion and may be a marker of brain reserve and compensatory abilities. SVD markers do not differ between TSI and stroke patients and probably do not fully capture the extent of brain vascular pathology and reserve.

High hair cortisol concentrations predict worse cognitive outcome after stroke: Results from the TABASCO prospective cohort study.

BACKGROUND AND PURPOSE: The role of stress-related endocrine dysregulation in the development of cognitive changes following a stroke needs further elucidation. We explored this issue in a longitudinal study on stroke survivors using hair cortisol concentrations (HCC), a measure of integrated long-term cortisol levels. METHODS: Participants were consecutive cognitively intact first-ever mild-moderate ischemic stroke/transient ischemic attack (TIA) survivors from the Tel Aviv Brain Acute Stroke Cohort (TABASCO) study. They underwent 3T magnetic resonance imaging (MRI) scanning and were cognitively assessed at admission, and at 6, 12 and 24 months post-stroke. Scalp hair samples were obtained during the initial hospitalization. RESULTS: Full data on baseline HCC, MRI scans and 2 years neuropsychological assessments were available for 65 patients. Higher HCC were significantly associated with a larger lesion volume and with worse cognitive results 6, 12 and 24 months post-stroke on most of the neurocognitive tests. 15.4% of the participants went on to develop clinically significant cognitive decline in the follow-up period, and higher HCC at baseline were found to be a significant risk factor for this decline, after adjustment for age, gender, body mass index and APOE e4 carrier status (HR=6.553, p=0.038). CONCLUSIONS: Our findings suggest that individuals with higher HCC, which probably reflect higher long-term cortisol release, are prone to develop cognitive decline following an acute stroke or TIA.

What are the correlates of cognition and participation to return to work after first ever mild stroke?

BACKGROUND: The percentage of working age people with mild stroke has risen. Evidence indicates that even mild stroke impact cognition, executive functioning, and daily functioning, consequently affecting participation, quality of life (QoL) and return to work (RTW). OBJECTIVES: (1) Compare cognition, participation and QoL between people 3 months post-mild stroke who RTW and those who did not; and (2) To determine the correlates of these variables to RTW of participants 3 months post-stroke. METHODS: We visited at home 163 stroke survivors (117 men, 46 women) 3 months post-mild stroke ranging from 50 to 89 years. Participants who returned to work (n = 114) and those who did not (n = 49). Data collection at home included measures for cognitive status (MoCA), executive functions (EFPT, DEX), depression (GDS), participation (RNL), and QoL (SIS recovery). RESULTS: Significant differences were found between RTW participants and those who did not RTW in measures of cognition, depression, participation and QoL (t = 2.36 to - 5.62, P < 0.022-0.001). No difference was found on age or gender. Stepwise regression showed that significant correlates of RTW were participation (RNL), executive functions (EFPT), and QoL (SIS recovery). CONCLUSIONS: To enable RTW after mild stroke, participation, executive functions and QoL must be considered in planning interventions.

Cognitive assessment in proximity to acute ischemic stroke/transient ischemic attack: comparison of the montreal cognitive assessment test and mindstreams computerized cognitive assessment battery.

BACKGROUND/AIMS: Even mild stroke survivors may sometimes experience residual cognitive damage. No consensus has emerged about which cognitive test is most appropriate for the diagnosis of poststroke cognitive impairment. We aim to compare a computerized battery of neuropsychological tests for memory, attention and executive functions (MindStreams®) with the Montreal Cognitive Assessment (MoCA) to detect mild-to-moderate cognitive impairments in poststroke patients. METHODS: Subjects enrolled to the TABASCO (Tel Aviv Brain Acute Stroke Cohort) study, a prospective study which includes consecutive first-ever mild-to-moderate stroke patients, were included. All participants underwent neurological and cognitive evaluations. RESULTS: A total of 454 patients with transient ischemic attack (TIA) or stroke are reported. Their mean MoCA and MindStreams scores were lower than normal; however, the TIA group presented significantly better scores using either method. The correlation between the MoCA and the computerized global score was 0.6 (p < 0.001). A significant correlation was found between the subcategory scores (executive function, memory and attention). However, the MoCA identified many more subjects with low scores (<26) compared to the MindStreams (70.6 vs. 15.7%). CONCLUSION: Our results demonstrate that either of the modalities alone is sensitive enough for identifying subtle cognitive impairment and none picks up substantially more cognitive losses than the other in patients with cerebrovascular disease.

Atherosclerosis and arteriosclerosis parameters in stroke patients associate with paraoxonase polymorphism and esterase activities.

BACKGROUND AND PURPOSE: Polymorphic paraoxonase (PON1) variants can variably prevent low- and high-density lipoprotein oxidation, but their role in provoking atherosclerosis remained unclear. We addressed this issue by profiling PON1 polymorphisms and enzymatic activities, and assessing atherosclerosis and cerebral arteriosclerosis severity in post-stroke patients. METHODS: Carotid artery intima-media-thickness (IMT), cerebral white matter lesions (WML), serum PON1 -108C/T, Q192R and L55M polymorphisms, and PON and acetylcholinesterase (AChE) enzyme activities were determined in 237 patients. RESULTS: Genetic variation at the PON1 locus showed a strong influence on PON1 activity in ischaemic stroke patients, but lacked direct influence on IMT. Stroke patients with PON1 QQ192 or MM55 genotypes demonstrated lower PON and arylesterase activities at both Day 1 and 12 months post-stroke than patients with either RQ/RR192 or LM/LL55 genotypes (P < 0.001). Furthermore, patients with carotid atherosclerosis and/or cerebral arteriosclerosis expressed as IMT, carotid plaques and WML had lower 12 months PON1 activity than patients without (P = 0.02, P = 0.027 and P = 0.001, respectively), and PON and AChE hydrolysis rates were more tightly correlated in patients carrying the PON1 192R compared with the 192QQ allele, in a gene dose-dependent manner (P < 0.001). CONCLUSION: Our findings show inverse PON1 activity-carotid atherosclerosis and -cerebral arteriosclerosis association in stroke patients: the lower the PON1 activity the more progressed is the atherosclerotic process and the weaker is the association with AChE activity. Extending previous PON1 genetic studies in stroke populations, our study emphasizes the PON1 activity as a potential anti-atherogenic element and proposes involvement of cholinesterase activities in its effects.

Interleukin-6 as an early predictor for one-year survival following an ischaemic stroke/transient ischaemic attack.

BACKGROUND: Early biomarkers for survival in an acute ischaemic stroke/transient ischaemic attack might serve as a useful tool for the clinician. Several studies have highlighted the role of inflammatory biomarkers as an early signal for acute ischaemic stroke prognosis. AIMS: This study examines the potential advantage of using high-sensitivity interleukin-6 as a possible biomarker at the early stages of acute stroke for identifying patients at a high risk for 12-month mortality. METHODS: Inflammatory biomarkers and neurological scores were determined in 250 patients following mild to moderate acute ischaemic stroke within 24 h of hospital admission. Outcome data on mortality were collected after 12 months. The signal detection methodology was used to identify subgroups that were at a high risk for 12-month mortality. RESULTS: Twelve months following the event, 234 of the 250 stroke patients survived. Signal detection identified predictors that distinguished individuals likely to die from those with a better recovery prediction. Plasma interleukin-6 concentration emerged as the optimal predictor, with a cut point of 6.47 pg/ml, chi(2) (l, N=250)=20.5, P<0.001. Interleukin-6 above 6.47 pg/ml during the acute phase predicted subsequent non-survival (P=0.006, odds ratio 8.0). CONCLUSIONS: This study demonstrates the clinical potential of using high-sensitivity interleukin-6 as an early signal for acute ischaemic stroke survival and suggests a clear cut point for patients at a high risk who might benefit from closer clinical surveillance and/or administration of therapeutic interventions.

Triggered C-reactive protein (CRP) concentrations and the CRP gene -717A>G polymorphism in acute stroke or transient ischemic attack.

C-reactive protein (CRP) increases following an acute stroke/transient ischemic attack (TIA), but the increment level varies among patients. We analyzed CRP concentrations during an acute stroke/TIA in relation to the CRP gene -717A>G polymorphism. Six months following an acute ischemic stroke/TIA, basal concentrations of CRP were measured in 507 controls and 219 patients and were found to be unassociated with the CRP -717A>G polymorphism. However, during the acute phase of stroke/TIA, individuals with the AG/GG genotype had significantly elevated CRP concentrations as opposed to those with the AA genotype (2.02 +/- 1.59 vs. 1.73 +/- 1.69 mg/l, P = 0.027). In addition, significant 3.22-fold increments in CRP concentrations was noted in individuals carrying the -717G allele when comparing the acute phase with the basal state of each patient and averaging the results. CRP -717A>G polymorphism is associated with triggered CRP concentrations during acute stroke/TIA. These findings might shed more light on the mechanisms of CRP elevation in acute ischemic stroke/TIA.

Wide-range C-reactive protein efficacy in acute ischemic stroke patients.

OBJECTIVE: To compare the recently introduced wide-range C-reactive protein (wr-CRP) with the widely used high-sensitivity Behring Dade method (hs-CRP) in acute stroke/transient ischemic attack (TIA) patients. MATERIALS AND METHODS: A total of 119 consecutive patients admitted to a tertiary medical center with acute ischemic stroke/TIA were included in the study. Venous blood was obtained for both assays during the first 24 h, 3-5 days, as well as 3-6 months thereafter. RESULTS: A highly significant correlation (r=0.994, P<0.0001) was found between the two methods even when analyzed at three different time points. In addition, a similar correlation was noted between these two assays and other commonly used biomarkers, including white blood cell count, Westergren's sedimentation rate and quantitative fibrinogen. CONCLUSION: Real-time, on-line and low-cost wr-CRP assay is a reasonable alternative to the Behring Dade hs-CRP method in acute stroke/TIA patients.