Peripheral glucose levels and cognitive outcome after ischemic stroke-Results from the Munich Stroke Cohort

Sirtuins and cognition: implications for learning and memory in neurological disorders

Sirtuins are an evolutionarily conserved family of regulatory proteins that function in an NAD+ -dependent manner. The mammalian family of sirtuins is composed of seven histone deacetylase and ADP-ribosyltransferase proteins (SIRT1-SIRT7) that are found throughout the different cellular compartments of the cell. Sirtuins in the brain have received considerable attention in cognition due to their role in a plethora of metabolic and age-related diseases and their ability to induce neuroprotection. More recently, sirtuins have been shown to play a role in normal physiological cognitive function, and aberrant sirtuin function is seen in pathological cellular states. Sirtuins are believed to play a role in cognition through enhancing synaptic plasticity, influencing epigenetic regulation, and playing key roles in molecular pathways involved with oxidative stress affecting mitochondrial function. This review aims to discuss recent advances in the understanding of the role of mammalian sirtuins in cognitive function and the therapeutic potential of targeting sirtuins to ameliorate cognitive deficits in neurological disorders.

Role of diabetes in stroke: Recent advances in pathophysiology and clinical management

The increasing prevalence of diabetes and stroke is a major global public health concern. Specifically, acute stroke patients, with pre-existing diabetes, pose a clinical challenge. It is established that diabetes is associated with a worse prognosis after acute stroke and the various biological factors that mediate poor recovery profiles in diabetic patients is unknown. The level of association and impact of diabetes, in the setting of reperfusion therapy, is yet to be determined. This article presents a comprehensive overview of the current knowledge of the role of diabetes in stroke, therapeutic strategies for primary and secondary prevention of cardiovascular disease and/or stroke in diabetes, and various therapeutic considerations that may apply during pre-stroke, acute, sub-acute and post-stroke stages. The early diagnosis of diabetes as a comorbidity for stroke, as well as tailored post-stroke management of diabetes, is pivotal to our efforts to limit the burden. Increasing awareness and involvement of neurologists in the management of diabetes and other cardiovascular risk factors is desirable towards improving stroke prevention and efficacy of reperfusion therapy in acute stroke patients with diabetes.

Management of tandem occlusions in acute ischemic stroke – intracranial versus extracranial first and extracranial stenting versus angioplasty alone: a systematic review and meta-analysis

Background

Optimal technical approaches of large-vessel anterior circulation acute ischemic strokes with concomitant extracranial internal carotid artery tandem occlusions is controversial.

Purpose

This systematic review and meta-analysis evaluates: the overall outcomes of patients with tandem occlusions treated with second-generation mechanical thrombectomy devices; differences in outcomes of extracranial versus intracranial first approaches; and differences in outcomes of extracranial stenting at time of procedure versus angioplasty alone.

Methods

MEDLINE, EMBASE, and the Web of Science was searched through September 2017 for studies evaluating patients presenting with acute tandem occlusions of the extracranial ICA and intracranial ICA, and/or proximal MCA treated with second-generation mechanical thrombectomy devices. Outcomes were pooled across studies using the random-effects model and expressed as cumulative incidence (event rate) and 95% CI.

Results

Thirty-three studies were included in analysis. Overall mRS≤0–2 at 90 days was 47% (95% CI 42% to 51%). No statistical difference was seen in 90-day mRS≤0–2 for patients treated with extracranial versus intracranial first approaches, 53% (95% CI 44% to 61%) vs 49% (95% CI 44% to 57%) (P=0.58). No statistical difference was seen in 90-day mRS≤0–2 for patients treated with extracranial stenting versus angioplasty alone, 49% (95% CI 42% to 56%) vs 49% (95% CI 33% to 65%) (P=0.39). No other statistical differences in outcome or safety were identified.

Conclusions

Nearly half of all tandem occlusion patients treated with mechanical thrombectomy have good neurological outcomes. No statistical differences in outcome are identified between extracranial first versus intracranial first approaches, nor extracranial stenting versus angioplasty alone.

Vascular Cognitive Impairment

Cerebrovascular disease typically manifests with stroke, cognitive impairment, or both. Vascular cognitive impairment refers to all forms of cognitive disorder associated with cerebrovascular disease, regardless of the specific mechanisms involved. It encompasses the full range of cognitive deficits from mild cognitive impairment to dementia. In principle, any of the multiple causes of clinical stroke can cause vascular cognitive impairment. Recent work further highlights a role of microinfarcts, microhemorrhages, strategic white matter tracts, loss of microstructural tissue integrity, and secondary neurodegeneration. Vascular brain injury results in loss of structural and functional connectivity and, hence, compromise of functional networks within the brain. Vascular cognitive impairment is common both after stroke and in stroke-free individuals presenting to dementia clinics, and vascular pathology frequently coexists with neurodegenerative pathology, resulting in mixed forms of mild cognitive impairment or dementia. Vascular dementia is now recognized as the second most common form of dementia after Alzheimer's disease, and there is increasing awareness that targeting vascular risk may help to prevent dementia, even of the Alzheimer type. Recent advances in neuroimaging, neuropathology, epidemiology, and genetics have led to a deeper understanding of how vascular disease affects cognition. These new findings provide an opportunity for the present reappraisal of vascular cognitive impairment. We further briefly address current therapeutic concepts.

Small-vessel occlusion versus large-artery atherosclerotic strokes in diabetics: Patient characteristics, outcomes, and predictors of stroke mechanism

INTRODUCTION

Diabetes mellitus exerts a detrimental effect on cerebral vasculature affecting both macrovasculature and microvasculature. However, although ischaemic stroke is typically included among macrovascular diabetic complications, it is frequently omitted from microvascular diabetic complications. We aimed to compare the proportion of large-artery atherosclerotic and small-vessel occlusion strokes among diabetic stroke patients, explore their differences and outcomes, and assess potential mechanisms which may determine why some diabetic patients suffer large-artery atherosclerotic stroke whereas others suffer small-vessel occlusion stroke.

METHODS

We pooled data of diabetic patients from four prospective ischaemic stroke registries (Acute Stroke Registry and Analysis of Lausanne (ASTRAL), Athens, Austrian, and Helsinki Stroke Thrombolysis Registries). Stroke severity and prognosis were assessed with National Institutes of Health Stroke Scale (NIHSS) and ASTRAL scores, respectively; functional outcome with three-month modified Rankin score (0-2 considered as favourable outcome). Logistic-regression analysis identified independent predictors of large-artery atherosclerotic stroke.

RESULTS

Among 5412 patients, 1069 (19.8%) were diabetics; of them, 232 (21.7%) had large-artery atherosclerotic and 205 (19.2%) small-vessel occlusion strokes. Large-artery atherosclerotic stroke had higher severity than small-vessel occlusion stroke (median NIHSS: 6 vs. 3, p < 0.001), worse prognosis (median ASTRAL score: 23 vs. 19, p < 0.001), and worse three-month outcome (60.3% vs. 83.4% with favourable outcome, p < 0.001). In logistic-regression analysis, peripheral artery disease (odds ratio: 4.013, 95% confidence interval: 1.667-9.665, p < 0.01) and smoking (odds ratio: 1.706, 95% confidence interval: 1.087-2.675, p < 0.05) were independently associated with large-artery atherosclerotic strokes.

CONCLUSION

In the diabetic stroke population, small-vessel occlusion and large-artery atherosclerotic strokes occur with similar frequency. Large-artery atherosclerotic strokes are more severe and have worse outcome than small-vessel occlusion strokes. The presence of peripheral artery disease and smoking independently predicted large-artery atherosclerotic stroke.