Markers of early vascular aging are not associated with cryptogenic ischemic stroke in the young: A case-control study

BACKGROUND AND PURPOSE

We aimed to assess the association between covert atherosclerosis, arterial stiffness, and early-onset cryptogenic ischemic stroke (CIS) in a prospective case-control study.

METHODS

We enrolled 123 young CIS patients (median age 41 years; 42% women) and 123 age- and sex-matched controls. Carotid intima-media thickness (CIMT), Augmentation Index (AIx), central pulse wave velocity (PWV), and subendocardial viability ratio (SEVR) were compared between patients and controls. Conditional logistic regression was used adjusting for age, systolic blood pressure, diastolic blood pressure, current smoking, total cholesterol/high-density lipoprotein cholesterol (Total-C/HDL-C) ratio, and glycated albumin to assess the independent association between CIMT, arterial stiffness and CIS.

RESULTS

Patients with higher CIMT and PWV were older, more often men and they had more frequently well-documented risk factors, lower HDL and higher Total-C/HDL-C ratio compared to other tertiles. In univariate comparisons, we found no differences between patients and controls regarding CIMT, AIx, or PWV. In the entire cohort, patients had a significantly lower SEVR compared to controls (146.3%, interquartile range [IQR] 125.7-170.3 vs. 158.0%, IQR 141.3-181.0, P=0.010). SEVR was lower also in women compared to their controls (132.0%, IQR 119.4-156.1 vs. 158.7%, IQR 142.0-182.8, P=0.001) but no significant difference appeared between male patients and male controls. However, after adjusting for comorbidities and laboratory values these significant differences were lost (odds ratio [OR] 1.52, 95% confidence interval [CI] 0.47-4.91) in the entire cohort and OR 3.89, 95% CI 0.30-50.80 in women).

CONCLUSIONS

Higher CIMT and PWV were associated to higher age, male sex, and several well-documented cardiovascular risk factors. However, in this study we could not prove that either covert atherosclerosis or arterial stiffness contribute to pathogenesis of early-onset CIS.

Glycemic control is not related to cerebral small vessel disease in neurologically asymptomatic individuals with type 1 diabetes

AIMS

To determine if medium- and long-term blood glucose control as well as glycemic variability, which are known to be strong predictors of vascular complications, are associated with underlying cerebral small vessel disease (cSVD) in neurologically asymptomatic individuals with type 1 diabetes.

METHODS

A total of 189 individuals (47.1% men; median age 40.0, IQR 33.0-45.2 years) with type 1 diabetes (median diabetes duration of 21.7, IQR 18.3-30.7 years) were enrolled in a cross-sectional retrospective study, as part of the Finnish Diabetic Nephropathy (FinnDiane) Study. Glycated hemoglobin (HbA_1c) values were collected over the course of ten years before the visit including a clinical examination, biochemical sampling, and brain magnetic resonance imaging. Markers of glycemic control, measured during the visit, included HbA_1c, fructosamine, and glycated albumin.

RESULTS

Signs of cSVD were present in 66 (34.9%) individuals. Medium- and long-term glucose control and glycemic variability did not differ in individuals with signs of cSVD compared to those without. Further, no difference in any of the blood glucose variables and cSVD stratified for cerebral microbleeds (CMBs) or white matter hyperintensities were detected. Neither were numbers of CMBs associated with the studied glucose variables. Additionally, after dividing the studied variables into quartiles, no association with cSVD was observed.

CONCLUSIONS

We observed no association between glycemic control and cSVD in neurologically asymptomatic individuals with type 1 diabetes. This finding was unexpected considering the large number of signs of cerebrovascular pathology in these people after two decades of chronic hyperglycemia and warrants further studies searching for underlying factors of cSVD.

Cerebral small-vessel disease is associated with the severity of diabetic retinopathy in type 1 diabetes

INTRODUCTION

Cerebral small-vessel disease is common in neurologically asymptomatic individuals with type 1 diabetes. The retinal vasculature is thought to mirror the brain's vasculature, but data on this association are limited in type 1 diabetes. Our aim was to study associations between diabetic retinopathy severity and cerebral small-vessel disease in type 1 diabetes.

RESEARCH DESIGN AND METHODS

For this cross-sectional study, we enrolled 189 participants with type 1 diabetes (median age 40 (33-45) years; 53% female; diabetes duration 21.6 (18.2-30.7) years) and 29 healthy age-matched and sex-matched controls as part of the Finnish Diabetic Nephropathy Study. Participants underwent a clinical investigation, brain MRI, and fundus imaging. Signs of cerebral small-vessel disease in brain MRIs were analyzed in relation to diabetic retinopathy severity (Early Treatment Diabetic Retinopathy Study (ETDRS) score).

RESULTS

In type 1 diabetes, participants with cerebral small-vessel disease had higher ETDRS scores (35 (20-61) vs 20 (20-35), p=0.022) and a higher prevalence of proliferative diabetic retinopathy than those without cerebral small-vessel disease (25% vs 9%, p=0.002). In adjusted analysis, proliferative diabetic retinopathy was associated with cerebral small-vessel disease (OR 2.57 (95% CI 1.04 to 6.35)). Median ETDRS score (35 (20-65) vs 20 (20-35), p=0.024) and proliferative diabetic retinopathy prevalence were higher (29% vs 13%, p=0.002) in participants with versus without cerebral microbleeds. ETDRS scores increased by number of cerebral microbleeds (p=0.001), both ETDRS score (OR 1.05 (95% CI 1.02 to 1.09)) and proliferative diabetic retinopathy (8.52 (95% CI 1.91 to 37.94)) were associated with >2 cerebral microbleeds in separate multivariable analysis. We observed no association with white matter hyperintensities or lacunar infarcts.

CONCLUSIONS

Presence of cerebral small-vessel disease on brain MRI, particularly cerebral microbleeds, is associated with the severity of diabetic retinopathy.

Endothelial Dysfunction is Associated With Early-Onset Cryptogenic Ischemic Stroke in Men and With Increasing Age

Background

The aim of this study was to assess the association between endothelial function and early‐onset cryptogenic ischemic stroke (CIS), with subgroup analyses stratified by sex and age groups.

Methods and Results

We prospectively enrolled 136 consecutive patients aged 18 to 49 years (median age, 41 years; 44% women) with a recent CIS and 136 age‐ and sex‐matched (±5 years) stroke‐free controls. Endothelial function was measured with an EndoPAT 2000 device and analyzed as tertiles of natural logarithm of reactive hyperemia index with lower values reflecting dysfunction. We used conditional logistic regression adjusting for age, education, hypertension, diabetes mellitus, dyslipidemia, current smoking, heavy drinking, obesity, and diet score to assess the independent association between endothelial function and CIS. Patients in the lowest tertile of natural logarithm of reactive hyperemia index were more often men and they more frequently had a history of dyslipidemia; they were also more often obese, had a lower diet score, and lower high‐density lipoprotein cholesterol. In the entire cohort, we found no association in patients with endothelial function and CIS compared with stroke‐free controls. In sex‐ and age‐specific analyses, endothelial dysfunction was associated with CIS in men (adjusted odds ratio [OR], 3.50 for lowest versus highest natural logarithm of reactive hyperemia index tertile; 95% CI, 1.22–10.07) and in patients ≥41 years (OR, 5.78; 95% CI, 1.52–21.95). These associations remained significant when dyslipidemia was replaced with the ratio of total to high‐density lipoprotein cholesterol.

Conclusions

Endothelial dysfunction appears to be an independent player in early‐onset CIS in men and patients approaching middle age.

Carotid intima-media thickness and arterial stiffness in relation to cerebral small vessel disease in neurologically asymptomatic individuals with type 1 diabetes

AIMS

To determine if arterial functional and structural changes are associated with underlying cerebral small vessel disease in neurologically asymptomatic individuals with type 1 diabetes.

METHODS

We enrolled 186 individuals (47.8% men; median age 40.0, IQR 33.0-45.0 years) with type 1 diabetes (median diabetes duration of 21.6, IQR 18.2-30.3 years), and 30 age- and sex-matched healthy controls, as part of the Finnish Diabetic Nephropathy (FinnDiane) Study. All individuals underwent a biochemical work-up, brain magnetic resonance imaging (MRI), ultrasound of the common carotid arteries and arterial tonometry. Arterial structural and functional parameters were assessed by carotid intima-media thickness (CIMT), pulse wave velocity and augmentation index.

RESULTS

Cerebral microbleeds (CMBs) were present in 23.7% and white matter hyperintensities (WMHs) in 16.7% of individuals with type 1 diabetes. Those with type 1 diabetes and CMBs had higher median (IQR) CIMT 583 (525 - 663) μm than those without 556 (502 - 607) μm, p = 0.016). Higher CIMT was associated with the presence of CMBs (p = 0.046) independent of age, eGFR, ApoB, systolic blood pressure, albuminuria, history of retinal photocoagulation and HbA_1c. Arterial stiffness and CIMT were increased in individuals with type 1 diabetes and WMHs compared to those without; however, these results were not independent of cardiovascular risk factors.

CONCLUSIONS

Structural, but not functional, arterial changes are associated with underlying CMBs in asymptomatic individuals with type 1 diabetes.

Comparison of Manual Cross-Sectional Measurements and Automatic Volumetry of the Corpus Callosum, and Their Clinical Impact: A Study on Type 1 Diabetes and Healthy Controls

Background and purpose: Degenerative change of the corpus callosum might serve as a clinically useful surrogate marker for net pathological cerebral impact of diabetes type 1. We compared manual and automatic measurements of the corpus callosum, as well as differences in callosal cross-sectional area between subjects with type 1 diabetes and healthy controls. Materials and methods: This is a cross-sectional study on 188 neurologically asymptomatic participants with type 1 diabetes and 30 healthy age- and sex-matched control subjects, recruited as part of the Finnish Diabetic Nephropathy Study. All participants underwent clinical work-up and brain MRI. Callosal area was manually measured and callosal volume quantified with FreeSurfer. The measures were normalized using manually measured mid-sagittal intracranial area and volumetric intracranial volume, respectively. Results: Manual and automatic measurements correlated well (callosal area vs. volume: ρ = 0.83, p < 0.001 and mid-sagittal area vs. intracranial volume: ρ = 0.82, p < 0.001). We found no significant differences in the callosal measures between cases and controls. In type 1 diabetes, the lowest quartile of normalized callosal area was associated with higher insulin doses (p = 0.029) and reduced insulin sensitivity (p = 0.033). In addition, participants with more than two cerebral microbleeds had smaller callosal area (p = 0.002). Conclusion: Manually measured callosal area and automatically segmented are interchangeable. The association seen between callosal size with cerebral microbleeds and insulin resistance is indicative of small vessel disease pathology in diabetes type 1.

The role of blood pressure in risk of ischemic and hemorrhagic stroke in type 1 diabetes

Background

Hypertension is one of the strongest risk factors for stroke in the general population, while systolic blood pressure has been shown to independently increase the risk of stroke in type 1 diabetes. The aim of this study was to elucidate the association between different blood pressure variables and risk of stroke in type 1 diabetes, and to explore potential nonlinearity of this relationship.

Methods

We included 4105 individuals with type 1 diabetes without stroke at baseline, participating in the nationwide Finnish Diabetic Nephropathy Study. Mean age at baseline was 37.4 ± 11.9 years, median duration of diabetes 20.9 (interquartile range 11.5–30.4) years, and 52% were men. Office systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured. Based on these pulse pressure (PP) and mean arterial pressure (MAP) were calculated. Strokes were classified based on medical and autopsy records, as well as neuroimaging. Cox proportional hazard models were performed to study how the different blood pressure variables affected the risk of stroke and its subtypes.

Results

During median follow-up time of 11.9 (9.21–13.9) years, 202 (5%) individuals suffered an incident stroke; 145 (72%) were ischemic and 57 (28%) hemorrhagic. SBP, DBP, PP, and MAP all independently increased the risk of any stroke. SBP, PP, and MAP increased the risk of ischemic stroke, while SBP, DBP, and MAP increased the risk of hemorrhagic stroke. SBP was strongly associated with stroke with a hazard ratio of 1.20 (1.11–1.29)/10 mmHg. When variables were modeled using restricted cubic splines, the risk of stroke increased linearly for SBP, MAP, and PP, and non-linearly for DBP.

Conclusions

The different blood pressure variables are all independently associated with increased risk of stroke in individuals with type 1 diabetes. The risk of stroke, ischemic stroke, and hemorrhagic stroke increases linearly at blood pressure levels less than the current recommended treatment guidelines.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0891-4) contains supplementary material, which is available to authorized users.

Clinical and MRI Features of Cerebral Small-Vessel Disease in Type 1 Diabetes

OBJECTIVE

To assess the prevalence of cerebral small-vessel disease (SVD) in subjects with type 1 diabetes compared with healthy control subjects and to characterize the diabetes-related factors associated with SVD.

RESEARCH DESIGN AND METHODS

This substudy was cross-sectional in design and included 191 participants with type 1 diabetes and median age 40.0 years (interquartile range 33.0-45.1) and 30 healthy age- and sex-matched control subjects. All participants underwent clinical investigation and brain MRIs, assessed for cerebral SVD.

RESULTS

Cerebral SVD was more common in participants with type 1 diabetes than in healthy control subjects: any marker 35% vs. 10% (P = 0.005), cerebral microbleeds (CMBs) 24% vs. 3.3% (P = 0.008), white matter hyperintensities 17% vs. 6.7% (P = 0.182), and lacunes 2.1% vs. 0% (P = 1.000). Presence of CMBs was independently associated with systolic blood pressure (odds ratio 1.03 [95% CI 1.00-1.05], P = 0.035).

CONCLUSIONS

Cerebral SVD, CMBs in particular, is more common in young people with type 1 diabetes compared with healthy control subjects.

Diabetes and intracerebral hemorrhage: baseline characteristics and mortality

BACKGROUND AND PURPOSE

Acknowledging the conflicting evidence for diabetes as a predictor of short- and long-term mortality following an intracerebral hemorrhage (ICH), we compared baseline characteristics and 30-day and long-term mortality between patients with and without diabetes after an ICH, paying special attention to differences between type 1 (T1D) and type 2 (T2D) diabetes.

METHODS

Patients with a first-ever ICH were followed for a median of 2.3 years. Adjusting for demographics, comorbidities and documented ICH characteristics increasing mortality after ICH, logistic regression analysis assessed factors associated with case fatality and 1-year survival among the 30-day survivors. Diabetes was compared with patients without diabetes in separate models as (i) any diabetes and (ii) T1D or T2D.

RESULTS

Of our 969 patients, 813 (83.9%) had no diabetes, 41 (4.2%) had T1D and 115 (11.9%) had T2D. Compared with patients without diabetes, those with diabetes were younger, more often men and more frequently had hypertension, coronary heart disease and chronic kidney disease, with similar ICH characteristics. Patients with T1D were younger, more often had chronic kidney disease and brainstem ICH, and less often had atrial fibrillation and lobar ICH, than did patients with T2D. Diabetes had no impact on case fatality. Any diabetes (odds ratio, 2.57; 1.19-5.52), T1D (odds ratio, 7.04; 1.14-43.48) and T2D (odds ratio, 2.32; 1.04-5.17) were independently associated with 1-year mortality.

CONCLUSIONS

Patients with ICH with diabetes exhibited a distinct pattern of comorbidities and disease characteristics with specific differences between T1D and T2D. Despite their younger age, T1D seems to carry a substantially higher likelihood of long-term mortality after an ICH than does T2D.

Prognosis and Its Predictors After Incident Stroke in Patients With Type 1 Diabetes

OBJECTIVE

Although patients with type 1 diabetes have a poor prognosis after a stroke, predictors of survival after an incident stroke in these patients are poorly studied.

RESEARCH DESIGN AND METHODS

In this observational study, a total of 144 patients of 4,083 with type 1 diabetes from the Finnish Diabetic Nephropathy (FinnDiane) Study suffered an incident stroke in 1997-2010, and were followed for a mean 3.4 ± 3.1 years after the stroke. Information was recorded on hard cardiovascular events and death as a result of cardiovascular or diabetes-related cause, collectively referred to as vascular composite end point. Information was collected from medical records, death certificates, and the National Care Register of Health Care. Predictors at the time of the incident stroke were studied for the end points.

RESULTS

During follow-up, 104 (72%) patients suffered a vascular composite end point. Of these, 33 (32%) had a recurrent stroke, 33 (32%) a hard cardiovascular event, and 76 (53%) died of cardiovascular or diabetes-related causes, with an overall 1-year survival of 76% and 5-year survival of 58%. The predictors of a vascular composite end point were hemorrhagic stroke subtype (hazard ratio 2.03 [95% CI 1.29-3.19]), as well as chronic kidney disease stage 2 (2.48 [1.17-5.24]), stage 3 (3.04 [1.54-6.04]), stage 4 (3.95 [1.72-9.04]), and stage 5 (6.71 [3.14-14.34]). All-cause mortality increased with deteriorating kidney function.

CONCLUSIONS

Patients with type 1 diabetes with an incident stroke have a poor cardiovascular prognosis and a high risk of all-cause mortality. In particular, hemorrhagic stroke subtype and progression of diabetic kidney disease conveys worse outcome.

Abstract TP216: Subtle Cardiovascular Measures in Young-onset Cryptogenic Ischemic Stroke: A Prospective Case-control Study

Background: Worldwide, ≈1.3 million annual ischemic strokes (IS) occur in young adults (<50 years of age), of which up to 50% remain cryptogenic after a complete diagnostic work-up. In a pilot case-control study, we studied the value of arterial stiffness and related subendocardial viability in the search of underlying pathophysiology in these patients.

Methods: We prospectively enrolled 51 patients aged 18-49 with recent imaging-positive cryptogenic IS and 51 age- and sex-matched stroke-free controls (NCT01934725). Measurements were done with an applanation tonometry (SphygmoCor). Augmentation Index (AIx) served as a measure of stiffness in small arteries. Aortic and brachial pulse wave velocities (aPWV; bPWV) reflected stiffness in large and intermediate-sized arteries, respectively. Subendocardial viability ratio (SEVR) was derived from radial artery waveform measures, reflecting myocardial oxygen supply and demand. Related-samples statistics were applied for univariate case-control analyses and linear regression to explore the relationship between parameters with significant association in case-control analysis.

Results: AIx, aPWV, bPWV, heart rate, and systolic or diastolic blood pressures did not differ statistically between patients and controls. Mean SEVR was significantly lower in patients compared with controls (148±35 vs. 161±29, P=0.003). In patients, higher heart rate was inversely associated with SEVR (P<0.001). Age, sex, migraine with and without aura, smoking, and systolic and diastolic blood pressure showed no independent association with SEVR.

Conclusions: To our knowledge, this is the first report to show an association between SEVR and stroke. Yet unrecognized subtle cardiovascular pathology may play a role in early-onset cryptogenic IS.

Abstract WP364: Diabetes Mellitus and Spontaneous Intracerebral Hemorrhage: Clinical Features and Mortality

Our previous findings suggest that ischemic stroke patients with either type 1 (T1D) or type 2 diabetes mellitus (T2D) exhibit a distinct risk factor and etiologic profile, and a worse vascular prognosis than do nondiabetic patients. We also showed that nonaneurysmal subarachnoid hemorrhage is rather a microvascular than macrovascular complication in T1D. Here, we aimed to compare risk factors, hematoma characteristics, and long-term mortality between diabetic and nondiabetic patients with spontaneous intracerebral hemorrhage (ICH) to provide information for patient management, counseling, and future research in these patient groups. Furthermore, we compared theses features between T1D and T2D patients.

Methods: We included patients with first-ever ICH enrolled in the Helsinki ICH Study and in the Finnish Diabetic Nephropathy Study. Patients were followed using the national death registry. A Cox proportional hazards model adjusting for age at ICH onset, sex, and known ICH prognosticators_Glasgow Coma Scale (GCS) on admission, hematoma volume, infratentorial location, intraventricular hematoma_was constructed to assess, whether diabetes stands as an independent prognosticator.

Results: A total of 972 patients were included, of which 813 (83.6%) were nondiabetic, 45 (4.6%) had T1D, and 120 (12.3%) T2D. Compared with nondiabetic patients, diabetic patients more often men, and they had more frequently hypertension and coronary heart disease. No difference emerged in GCS or hematoma volume, but diabetic patients more often had infratentorial ICH than nondiabetic patients. T1D patients were younger at ICH onset and they more often had brain stem ICH, but less often lobar ICH, than did T2D patients. Cumulative mortality at 12 months for nondiabetic patients was 34.0% (95% confidence interval 30.1-37.9%), for T1D 47.0% (31.3-62.7%), and for T2D 46.0% (36.2-55.8%). In multivariate Cox regression, diabetes was independently associated with higher risk of death (hazard ratio 1.42, 95% confidence interval 1.11-1.82, P=0.005).

Conclusions: ICH patients with diabetes exhibit a distinct pattern of comorbidities and ICH characteristics compared with nondiabetic patients. Diabetes independently decreases the likelihood for survival after an ICH.

Different risk factor profiles for ischemic and hemorrhagic stroke in type 1 diabetes mellitus

BACKGROUND AND PURPOSE

Despite the fact that patients with type 1 diabetes mellitus have a markedly increased risk of experiencing a stroke, independent risk factors for stroke and its subtypes in these patients have remained unclear.

METHODS

A total of 4083 patients with type 1 diabetes mellitus from the Finnish Diabetic Nephropathy (FinnDiane) Study, without a history of stroke at baseline, were included. Strokes were classified based on medical files and brain imaging. At baseline, mean age was 37.4±11.8 years, duration of diabetes mellitus was 20.0 (11.0-30.0) years, and 51% were men. During 9.0±2.7 years (36 680 patient-years) of follow-up, 105 patients experienced an ischemic stroke and 44 a hemorrhagic stroke. Cox proportional hazards analyses were performed to determine independent risk factors.

RESULTS

Independent risk factors for ischemic stroke were duration of diabetes mellitus, presence of diabetic nephropathy, higher hemoglobin A1c, higher systolic blood pressure, insulin resistance, and history of smoking, whereas sex, lipids, high-sensitivity C-reactive protein, and the metabolic syndrome were not associated with an increased risk. Diabetic nephropathy, severe diabetic retinopathy, higher systolic blood pressure, and lower body mass index were independently associated with hemorrhagic stroke.

CONCLUSIONS

The risk factor profile for ischemic stroke seems partly different from that of hemorrhagic stroke in patients with type 1 diabetes mellitus.

Incidence of stroke according to presence of diabetic nephropathy and severe diabetic retinopathy in patients with type 1 diabetes

OBJECTIVE

Type 1 diabetes is associated with a markedly increased risk of stroke, but only a few studies on the incidence of stroke in type 1 diabetes exist. Therefore, we assessed the incidence of stroke in patients with type 1 diabetes and studied the impact of diabetic nephropathy (DN) and severe diabetic retinopathy (SDR) on this risk.

RESEARCH DESIGN AND METHODS

We studied 4,083 patients with type 1 diabetes from the Finnish Diabetic Nephropathy Study. Mean age was 37.4 ± 11.8 years, duration of diabetes was 21.6 ± 12.1 years, and 52% were men. Strokes were identified from medical records, death certificates, and the National Hospital Discharge Register and classified based on medical files and brain images.

RESULTS

During 36,680 person-years of follow-up, 149 (4%) patients suffered an incident stroke (105 infarctions and 44 hemorrhages). Of the infarctions, 58 (55%) were lacunar. The incidence of stroke, cerebral infarction, and cerebral hemorrhage was 406 (95% CI 344-477), 286 (234-347), and 120 (87-161) per 100,000 person-years, respectively. In an adjusted analysis, microalbuminuria increased the risk of stroke with a hazard ratio (HR) of 3.2 (1.9-5.6), macroalbuminuria 4.9 (2.9-8.2), and end-stage renal disease 7.5 (4.2-13.3), and SDR increased the risk with an HR of 3.0 (1.9-4.5). The risk of cerebral infarction, cerebral hemorrhage, and lacunar infarction increased in a similar manner. The proportion of lacunar versus nonlacunar infarction did not change across DN groups.

CONCLUSIONS

The presence of SDR and DN, independently, increases the risk of stroke, cerebral infarction, and cerebral hemorrhage in patients with type 1 diabetes.

Subarachnoid hemorrhage in type 1 diabetes: a prospective cohort study of 4,083 patients with diabetes

OBJECTIVE

To estimate for the first time the incidence of subarachnoid hemorrhage (SAH) in type 1 diabetes.

RESEARCH DESIGN AND METHODS

Using the nationwide Finnish Diabetic Nephropathy (FinnDiane) Study cohort of 4,083 patients with type 1 diabetes (mean age of 37.4 ± 11.8 years at enrollment), we analyzed the incidence of first-ever SAH events.

RESULTS

During the follow-up time of 36,680 person-years (median 9.4 years), 15 patients with type 1 diabetes experienced an aneurysmal or nonaneurysmal SAH, and thus the crude incidence of SAH was 40.9 (95% CI 22.9-67.4) per 100,000 person-years. One patient had a verified aneurysmal SAH, and four patients died suddenly of an SAH, which was most likely caused by an aneurysm. SAHs in 10 out of 15 patients were classified as nonaneurysmal SAH, and thus the crude incidence of nonaneurysmal SAH was 27.3 (13.1-50.1) per 100,000 person-years. None of the nonaneurysmal SAHs were fatal. In univariate analysis, current smokers had a hazard ratio of 4.82 (95% CI 1.31-17.81) for nonaneurysmal SAH.

CONCLUSIONS

The incidence of nonaneurysmal SAH is high among patients with type 1 diabetes. Our findings suggest that nonaneurysmal SAH is a distinct new microvascular complication in type 1 diabetes.

Stroke mimics and intravenous thrombolysis

STUDY OBJECTIVE

The necessity for rapid administration of intravenous thrombolysis in patients with acute ischemic stroke may lead to treatment of patients with conditions mimicking stroke. We analyze stroke patients treated with intravenous thrombolysis in our center to characterize cases classified as stroke mimics.

METHODS

We identified and reviewed all cases with a diagnosis other than ischemic stroke in our large-scale single-center stroke thrombolysis registry. We compared these stroke mimics with patients with neuroimaging-negative and neuroimaging-positive ischemic stroke results.

RESULTS

Among 985 consecutive intravenous thrombolysis-treated patients, we found 14 stroke mimics (1.4%; 95% confidence interval 0.8% to 2.4%), 694 (70.5%) patients with neuroimaging-positive ischemic stroke results, and 275 (27.9%) patients with neuroimaging-negative ischemic stroke results. Stroke mimics were younger than patients with neuroimaging-negative or -positive ischemic stroke results. Compared with patients with neuroimaging-positive ischemic stroke results, stroke mimics had less severe symptoms at baseline and better 3-month outcome. No differences appeared in medical history or clinical features between stroke mimics and patients with neuroimaging-negative ischemic stroke results. None of the stroke mimics developed symptomatic intracerebral hemorrhage compared with 63 (9.1%) among patients with neuroimaging-positive ischemic stroke results and 6 (2.2%) among patients with neuroimaging-negative ischemic stroke results.

CONCLUSION

Stroke mimics were infrequent among intravenous thrombolysis-treated stroke patients in this cohort, and their treatment did not lead to harmful complications.

Factors associated with impaired kidney function and its impact on long-term outcome in young ischemic stroke

BACKGROUND AND PURPOSE

After ischemic stroke, kidney dysfunction is linked to poor outcomes in the elderly, but regarding young patients, data are lacking.

METHODS

We investigated estimated glomerular filtration rate (eGFR) on admission according to the Modification of Diet in Renal Disease equation in 958 consecutive patients aged 15 to 49 years with their first-ever ischemic stroke. Logistic regression adjusted for demographics and stroke risk factors served to identify factors related to low (<60) and high (>120 mL/min/1.73 m(2)) eGFR. In the long-term follow-up (mean, 8.9±3.8 years) study, Cox proportional hazards analysis described the association between eGFR and the following end points: nonfatal/fatal ischemic stroke; composite vascular event of any stroke, myocardial infarction, revascularization/other arterial occlusive event, or vascular death; and death of any cause.

RESULTS

Estimated GFR was normal in 809 (84.4%), low in 43 (4.5%), and high in 106 (11.1%) patients. Type 1 diabetes (OR, 18.84; 95% CI, 8.65 to 41.03), hypertension (4.29; 1.94 to 9.48), and cardiovascular disease (2.66; 1.19 to 5.96) were independently associated with low eGFR. Type 2 diabetes (3.82; 1.93 to 7.55), lower age (0.95 per year; 0.93 to 0.98), and male gender (1.74; 1.08 to 2.82) were associated with high eGFR. Both low (hazard ratio, 5.73; 95% CI, 3.54 to 9.25) and high eGFR (1.78; 1.01 to 3.14) were associated with long-term mortality when adjusted for age, gender, risk factors, stroke severity, and subtype. No independent association appeared between eGFR and vascular events.

CONCLUSIONS

Despite their different associated risk factors in our young patient cohort, both low and high eGFR predicted long-term mortality after ischemic stroke.

Spinal Epidural Hematoma as a Complication of Intravenous Thrombolysis in an Acute Ischemic Stroke Patient

An 80-year-old white male suffered a stroke, fell to the floor, and suffered acute right hemiparesis and facial palsy. After an intravenous alteplase infusion 2.5 h later, the patient first complained of numbness in his right arm, then neck pain, followed by left leg numbness and slowly progressing paraparesis. MRI of the spine demonstrated an acute spinal dorsal epidural hematoma extending from the C6 to the T6 level; 12 h later, he underwent hematoma evacuation and laminectomy. Three months after surgery, the patient was paraplegic with moderate sensory loss below mamillary level. Acute ischemic stroke is often associated with a sudden fall, which, after thrombolysis, may result in unusual hemorrhagic complications.

WITHDRAWN: Temporal and spatial expression patterns of laminins in ischemic adult rat brain

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Regeneration of adult rat spinal cord is promoted by the soluble KDI domain of gamma1 laminin

Regeneration in the central nervous system (CNS) of adult mammals is hampered by formation of a glial scar and by proteins released from the myelin sheaths of injured neuronal pathways. Our recent data indicate that the KDI (Lys-Asp-Ile) domain of gamma1 laminin neutralizes both glial- and myelin-derived inhibitory signals and promotes survival and neurite outgrowth of cultured human spinal cord neurons. We show that after complete transection of the adult rat spinal cord, animals receiving onsite infusion of the KDI domain via osmotic mini-pumps recover and are able to sustain their body weights and walk with their hindlimbs. Animals treated with placebo suffer from irreversible hindlimb paralysis. Microscopic and molecular analyses of the spinal cords indicate that the KDI domain reduces tissue damage at the lesion site and enables neurite outgrowth through the injured area to effect functional recovery of the initially paralyzed animals. That the KDI domain enhances regeneration of acute spinal cord injuries in the adult rat suggests that it may be used to promote regeneration of spinal cord injuries in humans.

The neuroprotective KDI domain of γ1-laminin is a universal and potent inhibitor of ionotropic glutamate receptors

Previous work from this laboratory indicates that the KDI (Lys-Asp-Ile) domain of gamma 1-laminin promotes functional regeneration of adult rat spinal cord injuries and protects adult rat hippocampal neurons against massive neuronal death induced by intracerebral injection of the glutamate analogue kainic acid. In the present study, we used patch clamp recordings on cultured human embryonic neocortical neurons and HEK 293 cells expressing recombinant glutamate receptor subunits to study a putative interaction of the KDI with the glutamate system. We show that the KDI domain of gamma 1-laminin is a universal and potent inhibitor of AMPA, kainate, and NMDA subclasses of glutamate receptors, with a noncompetitive action on the AMPA receptor channel activity. Glutamate neurotoxicity plays a key role in both CNS trauma and neurodegenerative disorders, so this unexpected, novel function of the gamma 1-laminin-derived tripeptide may prove clinically valuable in treatment of CNS trauma and/or disease.

Soluble KDI domain of γ1 laminin protects adult hippocampus from excitotoxicity of kainic acid

Recent data indicate that the soluble KDI domain of gamma1 laminin promotes survival and neurite outgrowth of human central neurons in vitro (Liebkind et al.[2003] J Neurosci Res 73:637-643), and seems to neutralize both glia- and myelin-derived signals that hamper regeneration in the central nervous system (CNS) of adult mammals. We show that damage of adult rat neocortical and hippocampal areas by a stereotaxic injection of kainic acid (KA) is prevented by a preceding injection of the soluble KDI domain. In the presence of the KDI domain, both neocortical and hippocampal areas show extensive gliosis but have viable neurons and glial cells, which are absent and the areas fully destroyed after injection of KA alone. This result indicates that the KDI domain of the gamma1 laminin protects the CNS against excitotoxic insults and promotes survival of both neurons and glial cells. The KDI domain may thus be a potential drug to prevent CNS damage induced by neurodegenerative disorders, mechanical injury, or ischemia.

Angeli's salt and spinal motor neuron injury

Nitroxyl anion or its conjugate acid (NO-/HNO) and nitric oxide (NO) may both have pro-oxidative and cytotoxic properties. Superoxide dismutase (SOD) enzyme has been shown to convert reversibly HNO to NO. Mutations found in the SOD enzyme in some familial amyotrophic lateral sclerosis (ALS) patients affect redox properties of the SOD enzyme in a manner, which may affect the equilibrium between NO and HNO. Therefore, we studied the effects of HNO releasing compound, Angeli's salt (AS), on both motor and sensory functions after intrathecal administration in the lumbar spinal cord of a male rat. These functions were measured by rotarod, spontaneous activity, paw- and tail-flick tests. In addition, we compared the effect of AS to NO releasing papanonoate, old AS solution and sulphononoate in the motor performance test. The effect of intrathecal delivery of AS on the markers of the spinal cord injury and oxidative/nitrosative stress were further studied.

RESULTS

Freshly prepared AS (5 or 10 micromol), but not papanonoate, caused a marked decrease in the rotarod performance 3-7 days after the intrathecal administration. The peak motor deficiency was noted 3 days after AS (5 micromol) delivery. Old, degraded, AS solution and nitrous oxide releasing sulphononoate did not decrease motor performance in the rotarod test. AS did not affect the sensory stimulus evoked responses as measured by the paw-flick and tail-flick tests. Immunohistological examination revealed that AS caused injury related changes in the expression of glial fibrillary acidic protein (GFAP), fibroblast growth factor (FGF-2) and laminins in the spinal cord. Moreover, AS increased nitrotyrosine immunoreactivity in the spinal motor neurons. Therefore, we conclude that AS, but not NO releasing papanonoate, causes motor neuron injury but does not affect the function of sensory nerves in behavioural tests.

Peripapillary atrophy in the unilateral exfoliation syndrome

PURPOSE

To compare the areas of peripapillary atrophy between fellow eyes in patients with unilateral exfoliation syndrome.

METHODS

Topographic measurements for peripapillary atrophy and the optic nerve head with confocal scanning laser ophthalmoscopy, using the Heidelberg Retina Tomograph were performed on 45 nonglaucomatous patients with unilateral exfoliation syndrome. The area of peripapillary atrophy was divided into an alpha and a beta zone. The areas of alpha and beta peripapillary atrophy and their angular extents around the disc were measured. The frequency distributions of the alpha and beta areas and their largest radial extents at different positions around the disc were calculated.

RESULTS

An alpha area was detected in 84% of the exfoliative and 89% of the nonexfoliative fellow eyes, and a beta area in 31% and 42% of eyes, respectively. The exfoliative and the fellow nonexfoliative eyes did not differ in the sizes of the alpha (0.43+/-0.46 vs 0.33+/-0.18 mm(2), P=0.68) and beta (0.14+/-0.30 vs 0.17+/-0.34 mm(2), P=0.96) areas of peripapillary atrophy. The angular extents, the locations of the largest radial extent, and the frequency distributions of the alpha and beta peripapillary atrophy areas were similar in fellow eyes.

CONCLUSION

Exfoliation syndrome itself is not a risk factor for peripapillary atrophy.

Is the soluble KDI domain of gamma1 laminin a regeneration factor for the mammalian central nervous system?

Regeneration of adult mammalian CNS is poor as a result of environmental factors that prevent axon growth. The major factors hampering regeneration of central axons include proteins released from the damaged myelin sheets of the injured neuronal pathways and formation of the glial scar. By using an experimental model of human CNS injury, we show that survival and neurite outgrowth of human central neurons are significantly enhanced by the soluble KDI domain of gamma1 laminin. Our results indicate that the KDI domain appears to neutralize both glia-derived inhibitory signals and inhibitory molecules released from the myelin of the adult human spinal cord. We propose that the KDI domain may enhance regeneration of injuries in the adult mammalian CNS.

Gamma 1 laminin and its biologically active KDI-domain may guide axons in the floor plate of human embryonic spinal cord

Immunocytochemistry, in situ hybridization and Matrigel-embedded cultures were used to investigate the distribution of laminins during development of the human embryonic spinal cord (7-11 weeks). Our results indicate that alpha 1, beta 1, beta 3 and gamma 1 laminins localize as punctate deposits in the floor plate region in association with commissural fibers crossing the ventral midline. In addition, the neurite outgrowth domain of gamma 1 laminin accumulates heavily in the floor plate region, in the notochord and in GFAP-immunoreactive glial fibers of the embryonic spinal cord. In culture experiments, the biologically active KDI-domain of gamma 1 laminin selectively attracted directional outgrowth of neurites from explants of the dorsal spinal cord. The spatial and temporal colocalization of punctate deposits of laminins with nerve fibers crossing the ventral midline, and the guidance of neurites by the KDI-peptide domain, indicate that laminins, specifically the gamma 1 laminin, may be involved in guidance of axons during embryonic development of the human spinal cord.