The very long-term risk and predictors of recurrent ischaemic events after a stroke at a young age: The FUTURE study

Introduction

Patients who suffer a stroke at a young age, remain at a substantial risk of developing recurrent vascular events and information on very long-term prognosis and its risk factors is indispensable. Our aim is to investigate this very long-term risk and associated risk factors up to 35 years after stroke.

Patients and methods

Prospective cohort study among 656 patients with a first-ever ischaemic stroke or transient ischaemic stroke (TIA), aged 18-50, who visited our hospital (1980-2010). Outcomes assessed at follow-up (2014-2015) included TIA or ischaemic stroke and other arterial events, whichever occurred first. Kaplan-Meier analysis quantified cumulative risks. A prediction model was constructed to assess risk factors independently associated with any ischaemic event using Cox proportional hazard analyses followed by bootstrap validation procedure to avoid overestimation.

Results

Mean follow-up was 12.4 (SD 8.2) years (8105 person-years). Twenty-five years cumulative risk was 45.4% (95%CI: 39.4-51.5) for any ischaemic event, 30.1% (95%CI: 24.8-35.4) for cerebral ischaemia and 27.0% (95%CI: 21.1-33.0) for other arterial events. Risk factors retained in the prediction model were smoking (HR 1.35, 95%CI: 1.04-1.74), poor kidney function (HR 2.10, 95%CI: 1.32-3.35), history of peripheral arterial disease (HR 2.10, 95%CI: 1.08-3.76) and cardiac disease (HR 1.84, 95%CI: 1.06-3.18) (C-statistic 0.59 (95%CI: 0.55-0.64)).

Discussion and conclusion

Young stroke patients remain at a substantial risk for recurrent events; almost 1 of 2 develops a recurrent ischaemic event and 1 of 3 develops a recurrent stroke or TIA during 25 years of follow-up. Risk factors independently associated with recurrent events were poor kidney function, smoking, history of peripheral arterial disease and cardiac disease.

Baseline Cerebral Small Vessel Disease Is Not Associated with Gait Decline After Five Years

Background

Cerebral small vessel disease (SVD) is cross-sectionally associated with gait disturbances, however, the relation between baseline SVD and gait decline over time is uncertain. Furthermore, diffusion tensor imaging (DTI) studies on gait decline are currently lacking.

Objective

To investigate the association between baseline imaging SVD markers and gait decline.

Methods

In 2006, 310 participants from the RUN DMC cohort, a prospective cohort with older adults aged 50-85 years with SVD, were included. Gait variables were assessed using a computerized walkway during baseline and follow-up. Linear and logistic regression analyses were used to investigate the relation between imaging measures and gait decline and incident gait impairment (speed ≤ 1.0 m/s). Tract-based spatial statistics (TBSS) was used to identify possible differences in DTI measures of white matter tracts between participants with and without incident gait impairment.

Results

Mean age was 63.3 years (SD: 8.4) and mean follow-up duration 5.4 years (SD: 0.2). No significant associations between imaging measures and gait decline were found. TBSS analysis revealed no significant differences in DTI measures between participants with and without incident gait impairment after additional adjustment for SVD. In sub-analyses, a high total WMH volume (OR: 2.8 for highest quartile, 95% CI: 1.1-7.1) and high infratentorial WMH volume (OR: 1.8 per SD increase, 95% CI: 1.1-2.9) were associated with an increased 5-year risk of gait impairment, although this was not significant after correction for multiple testing.

Conclusion

Baseline imaging SVD markers were not associated with gait decline or incident gait impairment after 5 years. Future studies should investigate if SVD progression is related to gait deterioration.

Remote Lower White Matter Integrity Increases the Risk of Long-Term Cognitive Impairment After Ischemic Stroke in Young Adults

Background and Purpose—

Poststroke cognitive impairment occurs frequently in young patients with ischemic stroke (18 through 50 years of age). Accumulating data suggest that stroke is associated with lower white matter integrity remote from the stroke impact area, which might explain why some patients have good long-term cognitive outcome and others do not. Given the life expectancy of decades in young patients, we therefore investigated remote white matter in relation to long-term cognitive function.

Methods—

We included all consecutive first-ever ischemic stroke patients, left/right hemisphere, without recurrent stroke or transient ischemic attack during follow-up, aged 18 through 50 years, admitted to our university medical center between 1980 and 2010. One hundred seventeen patients underwent magnetic resonance imaging scanning including a T1-weighted scan, a diffusion tensor imaging scan, and completed a neuropsychological assessment. Patients were compared with a matched stroke-free control group (age, sex, and education matched). Cognitive impairment was defined as >1.5 SD below the mean cognitive index score of controls and no cognitive impairment as ≤1 SD. Tract-Based Spatial Statistics was used to assess the white matter integrity (fractional anisotropy and mean diffusivity).

Results—

About 11 years after ischemic stroke, lower remote white matter integrity was associated with a worse long-term cognitive performance. A lower remote white matter integrity, even in the contralesional hemisphere, was observed in cognitively impaired patients (n=25) compared with cognitively unimpaired patients (n=71).

Conclusions—

These findings indicate that although stroke has an acute onset, it might have long lasting effects on remote white matter integrity and thereby increases the risk of long-term cognitive impairment.

Factors Associated With 8-Year Mortality in Older Patients With Cerebral Small Vessel Disease: The Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC) Study

IMPORTANCE

Gait and cognition have been related to mortality in population-based studies. This association is possibly mediated by cerebral small vessel disease (SVD), which has been associated with mortality as well. It is unknown which factors can predict mortality in individuals with SVD. Identification of high-risk patients may provide insight into factors that reflect their vital health status.

OBJECTIVES

To assess mortality in patients with cerebral SVD and identify potential clinical and/or imaging factors associated with mortality.

DESIGN, SETTING, AND PARTICIPANTS

A prospective, single-center cohort study was conducted. The present investigation is embedded in the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC) study. Between January 17, 2006, and February 27, 2007, all participants underwent a cognitive and motor assessment and cerebral magnetic resonance imaging (MRI) including a diffusion tensor imaging sequence to assess microstructural integrity of the white matter. Participants were followed up until their death or November 24, 2014. Participants included 503 older adults with SVD noted on brain imaging. Data analysis was performed from November 26, 2014, to February 2, 2015.

MAIN OUTCOMES AND MEASURES

Eight-year all-cause mortality.

RESULTS

Of 503 participants (mean [SD] age, 65.7 [8.8] years; range, 50-85 years; 284 [56.5%] were male), 80 individuals (15.9%) died during a mean (SD) follow-up of 7.8 (1.5) years. In the final analysis, 494 (98.2%) were included, of whom 78 (15.8%) died. Gait speed, cognitive index, conventional MRI markers of SVD (white matter hyperintensity volume, brain volume, and lacunes), and diffusion measures of the white matter were associated with an 8-year risk of mortality independent of age, sex, and vascular risk factors. The prediction of mortality was determined using Cox proportional hazards models with backward stepwise selection and including age, sex, vascular risk factors, gait speed, cognitive index, MRI, and diffusion measures. Results are reported as hazard ratios (HRs) (95% CI). Older age (1.05 per 1-year increase [1.01-1.08]), lower gait speed (1.15 per 0.1-m/s slower gait [1.06-1.24]), lower gray matter volume (0.72 per 1-SD increase [0.55-0.95]), and greater global mean diffusivity of the white matter (1.51 per 1-SD increase [1.19-1.92]) were identified as the main factors associated with mortality. Cognitive index and other conventional SVD markers were not retained in the prediction model.

CONCLUSIONS AND RELEVANCE

Gait, cognition, and imaging markers of SVD are associated with 8-year risk of mortality. In the prediction of mortality, an older age, lower gait speed, lower gray matter volume, and greater global mean diffusivity of white matter at baseline best predicted mortality in our population. Further research is needed to investigate the reproducibility of this prediction model and to elucidate the association between the factors identified and mortality.

Accelerated development of cerebral small vessel disease in young stroke patients

Objective:

To study the long-term prevalence of small vessel disease after young stroke and to compare this to healthy controls.

Methods:

This prospective cohort study comprises 337 patients with an ischemic stroke or TIA, aged 18–50 years, without a history of TIA or stroke. In addition, 90 age- and sex-matched controls were included. At follow-up, lacunes, microbleeds, and white matter hyperintensity (WMH) volume were assessed using MRI. To investigate the relation between risk factors and small vessel disease, logistic and linear regression were used.

Results:

After mean follow-up of 9.9 (SD 8.1) years, 337 patients were included (227 with an ischemic stroke and 110 with a TIA). Mean age of patients was 49.8 years (SD 10.3) and 45.4% were men; for controls, mean age was 49.4 years (SD 11.9) and 45.6% were men. Compared with controls, patients more often had at least 1 lacune (24.0% vs 4.5%, p < 0.0001). In addition, they had a higher WMH volume (median 1.5 mL [interquartile range (IQR) 0.5–3.7] vs 0.4 mL [IQR 0.0–1.0], p < 0.001). Compared with controls, patients had the same volume WMHs on average 10–20 years earlier. In the patient group, age at stroke (β = 0.03, 95% confidence interval [CI] 0.02–0.04) hypertension (β = 0.22, 95% CI 0.04–0.39), and smoking (β = 0.18, 95% CI 0.01–0.34) at baseline were associated with WMH volume.

Conclusions:

Patients with a young stroke have a higher burden of small vessel disease than controls adjusted for confounders. Cerebral aging seems accelerated by 10–20 years in these patients, which may suggest an increased vulnerability to vascular risk factors.

Collateral Status on Baseline Computed Tomographic Angiography and Intra-Arterial Treatment Effect in Patients With Proximal Anterior Circulation Stroke

Background and Purpose—

Recent randomized trials have proven the benefit of intra-arterial treatment (IAT) with retrievable stents in acute ischemic stroke. Patients with poor or absent collaterals (preexistent anastomoses to maintain blood flow in case of a primary vessel occlusion) may gain less clinical benefit from IAT. In this post hoc analysis, we aimed to assess whether the effect of IAT was modified by collateral status on baseline computed tomographic angiography in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN).

Methods—

MR CLEAN was a multicenter, randomized trial of IAT versus no IAT. Primary outcome was the modified Rankin Scale at 90 days. The primary effect parameter was the adjusted common odds ratio for a shift in direction of a better outcome on the modified Rankin Scale. Collaterals were graded from 0 (absent) to 3 (good). We used multivariable ordinal logistic regression analysis with interaction terms to estimate treatment effect modification by collateral status.

Results—

We found a significant modification of treatment effect by collaterals ( P =0.038). The strongest benefit (adjusted common odds ratio 3.2 [95% confidence intervals 1.7–6.2]) was found in patients with good collaterals (grade 3). The adjusted common odds ratio was 1.6 [95% confidence intervals 1.0–2.7] for moderate collaterals (grade 2), 1.2 [95% confidence intervals 0.7–2.3] for poor collaterals (grade 1), and 1.0 [95% confidence intervals 0.1–8.7] for patients with absent collaterals (grade 0).

Conclusions—

In MR CLEAN, baseline computed tomographic angiography collateral status modified the treatment effect. The benefit of IAT was greatest in patients with good collaterals on baseline computed tomographic angiography. Treatment benefit appeared less and may be absent in patients with absent or poor collaterals.

Clinical Trial Registration—

URL: http://www.trialregister.nl and http://www.controlled-trials.com . Unique identifier: (NTR)1804 and ISRCTN10888758, respectively.

Time to Reperfusion and Treatment Effect for Acute Ischemic Stroke: A Randomized Clinical Trial

IMPORTANCE

Intra-arterial treatment (IAT) for acute ischemic stroke caused by intracranial arterial occlusion leads to improved functional outcome in patients treated within 6 hours after onset. The influence of treatment delay on treatment effect is not yet known.

OBJECTIVE

To evaluate the influence of time from stroke onset to the start of treatment and from stroke onset to reperfusion on the effect of IAT.

DESIGN, SETTING, AND PARTICIPANTS

The Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) was a multicenter, randomized clinical open-label trial of IAT vs no IAT in 500 patients. The time to the start of treatment was defined as the time from onset of symptoms to groin puncture (TOG). The time from onset of treatment to reperfusion (TOR) was defined as the time to reopening the vessel occlusion or the end of the procedure in cases for which reperfusion was not achieved. Data were collected from December 3, 2010, to June 3, 2014, and analyzed (intention to treat) from July 1, 2014, to September 19, 2015.

MAIN OUTCOMES AND MEASURES

Main outcome was the modified Rankin Scale (mRS) score for functional outcome (range, 0 [no symptoms] to 6 [death]). Multiple ordinal logistic regression analysis estimated the effect of treatment and tested for the interaction of time to randomization, TOG, and TOR with treatment. The effect of treatment as a risk difference on reaching independence (mRS score, 0-2) was computed as a function of TOG and TOR. Calculations were adjusted for age, National Institutes of Health Stroke Scale score, previous stroke, atrial fibrillation, diabetes mellitus, and intracranial arterial terminus occlusion.

RESULTS

Among 500 patients (58% male; median age, 67 years), the median TOG was 260 (interquartile range [IQR], 210-311) minutes; median TOR, 340 (IQR, 274-395) minutes. An interaction between TOR and treatment (P = .04) existed, but not between TOG and treatment (P = .26). The adjusted risk difference (95% CI) was 25.9% (8.3%-44.4%) when reperfusion was reached at 3 hours, 18.8% (6.6%-32.6%) at 4 hours, and 6.7% (0.4%-14.5%) at 6 hours.

CONCLUSION AND RELEVANCE

For every hour of reperfusion delay, the initially large benefit of IAT decreases; the absolute risk difference for a good outcome is reduced by 6% per hour of delay. Patients with acute ischemic stroke require immediate diagnostic workup and IAT in case of intracranial arterial vessel occlusion.

TRIAL REGISTRATION

trialregister.nl Identifier: NTR1804.

The Prognostic Value of CT Angiography and CT Perfusion in Acute Ischemic Stroke

Background: CT angiography (CTA) and CT perfusion (CTP) are important diagnostic tools in acute ischemic stroke. We investigated the prognostic value of CTA and CTP for clinical outcome and determined whether they have additional prognostic value over patient characteristics and non-contrast CT (NCCT). Methods: We included 1,374 patients with suspected acute ischemic stroke in the prospective multicenter Dutch acute stroke study. Sixty percent of the cohort was used for deriving the predictors and the remaining 40% for validating them. We calculated the predictive values of CTA and CTP predictors for poor clinical outcome (modified Rankin Scale score 3-6). Associations between CTA and CTP predictors and poor clinical outcome were assessed with odds ratios (OR). Multivariable logistic regression models were developed based on patient characteristics and NCCT predictors, and subsequently CTA and CTP predictors were added. The increase in area under the curve (AUC) value was determined to assess the additional prognostic value of CTA and CTP. Model validation was performed by assessing discrimination and calibration. Results: Poor outcome occurred in 501 patients (36.5%). Each of the evaluated CTA measures strongly predicted outcome in univariable analyses: the positive predictive value (PPV) was 59% for Alberta Stroke Program Early CT Score (ASPECTS) ≤7 on CTA source images (OR 3.3; 95% CI 2.3-4.8), 63% for presence of a proximal intracranial occlusion (OR 5.1; 95% CI 3.7-7.1), 66% for poor leptomeningeal collaterals (OR 4.3; 95% CI 2.8-6.6), and 58% for a >70% carotid or vertebrobasilar stenosis/occlusion (OR 3.2; 95% CI 2.2-4.6). The same applied to the CTP measures, as the PPVs were 65% for ASPECTS ≤7 on cerebral blood volume maps (OR 5.1; 95% CI 3.7-7.2) and 53% for ASPECTS ≤7 on mean transit time maps (OR 3.9; 95% CI 2.9-5.3). The prognostic model based on patient characteristics and NCCT measures was highly predictive for poor clinical outcome (AUC 0.84; 95% CI 0.81-0.86). Adding CTA and CTP predictors to this model did not improve the predictive value (AUC 0.85; 95% CI 0.83-0.88). In the validation cohort, the AUC values were 0.78 (95% CI 0.73-0.82) and 0.79 (95% CI 0.75-0.83), respectively. Calibration of the models was satisfactory. Conclusions: In patients with suspected acute ischemic stroke, admission CTA and CTP parameters are strong predictors of poor outcome and can be used to predict long-term clinical outcome. In multivariable prediction models, however, their additional prognostic value over patient characteristics and NCCT is limited in an unselected stroke population.

Lower Ipsilateral Hippocampal Integrity after Ischemic Stroke in Young Adults: A Long-Term Follow-Up Study

Background and purpose

Memory impairment after stroke is poorly understood as stroke rarely occurs in the hippocampus. Previous studies have observed smaller ipsilateral hippocampal volumes after stroke compared with controls. Possibly, these findings on macroscopic level are not the first occurrence of structural damage and are preceded by microscopic changes that may already be associated with a worse memory function. We therefore examined the relationship between hippocampal integrity, volume, and memory performance long after first-ever ischemic stroke in young adults.

Methods

We included all consecutive first-ever ischemic stroke patients, without hippocampal strokes or recurrent stroke/TIA, aged 18–50 years, admitted to our academic hospital between 1980 and 2010. One hundred and forty-six patients underwent T1 MPRAGE, DTI scanning and completed the Rey Auditory Verbal Learning Test and were compared with 84 stroke-free controls. After manual correction of hippocampal automatic segmentation, we calculated mean hippocampal fractional anisotropy (FA) and diffusivity (MD).

Results

On average 10 years after ischemic stroke, lesion volume was associated with lower ipsilateral hippocampal integrity (p<0.05), independent of hippocampal volume. In patients with a normal ipsilateral hippocampal volume (volume is less than or equal to 1.5 SD below the mean volume of controls) significant differences in ipsilateral hippocampal MD were observed (p<0.0001). However, patients with a normal hippocampal volume and high hippocampal MD did not show a worse memory performance compared with patients with a normal volume and low hippocampal MD (p>0.05).

Conclusions

Patients with average ipsilateral hippocampal volume could already have lower ipsilateral hippocampal integrity, although at present with no attendant worse memory performance compared with patients with high hippocampal integrity. Longitudinal studies are needed to investigate whether a low hippocampal integrity after stroke might lead to exacerbated memory decline with increasing age.

Cerebral small vessel disease and incident parkinsonism: The RUN DMC study

OBJECTIVE

To investigate the relation between baseline cerebral small vessel disease (SVD) and the risk of incident parkinsonism using different MRI and diffusion tensor imaging (DTI) measures.

METHODS

In the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC) study, a prospective cohort study, 503 elderly participants with SVD and without parkinsonism were included in 2006. During follow-up (2011-2012), parkinsonism was diagnosed according to UK Brain Bank criteria. Cox regression analysis was used to investigate the association between baseline imaging measures and incident all-cause parkinsonism and vascular parkinsonism (VP). Tract-based spatial statistics analysis was used to identify differences in baseline DTI measures of white matter (WM) tracts between participants with VP and without parkinsonism.

RESULTS

Follow-up was available from 501 participants (mean age 65.6 years; mean follow-up duration 5.2 years). Parkinsonism developed in 20 participants; 15 were diagnosed with VP. The 5-year risk of (any) parkinsonism was increased for those with a high white matter hyperintensity (WMH) volume (hazard ratio [HR] 1.8 per SD increase, 95% confidence interval [CI] 1.3-2.4) and a high number of lacunes (HR 1.4 per number increase, 95% CI 1.1-1.8) at baseline. For VP, this risk was also increased by the presence of microbleeds (HR 5.7, 95% CI 1.9-16.8) and a low gray matter volume (HR 0.4 per SD increase, 95% CI 0.2-0.8). Lower fractional anisotropy values in bifrontal WM tracts involved in movement control were observed in participants with VP compared to participants without parkinsonism.

CONCLUSIONS

SVD at baseline, especially a high WMH volume and a high number of lacunes, is associated with incident parkinsonism. Our findings favor a role of SVD in the etiology of parkinsonism.

Post-stroke fatigue and its association with poor functional outcome after stroke in young adults

INTRODUCTION

Post-stroke fatigue negatively influences short-term functional outcome in older stroke survivors. In young adults, in the midst of their active working and family life, this influence may even be more pronounced. However, there are only few studies on this topic in young patients with stroke. Therefore, we investigated the long-term prevalence of post-stroke fatigue in patients with a young transient ischaemic attack (TIA) or ischaemic stroke and its association with functional outcome.

METHODS

This study is part of a large cohort study among 511 stroke survivors with a first-ever TIA or ischaemic stroke, aged 18-50 years. After a mean follow-up of 9.8 (SD 8.4) years, we assessed the presence of fatigue with the fatigue subscale of the Checklist Individual Strength questionnaire and functional outcome. Prevalence of fatigue between young patients with stroke and 147 stroke-free sex-matched and age-matched controls was compared. OR's for poor functional outcome on modified Rankin Score (mRS>2) and Instrumental Activities of Daily Living (IADL<8) and cognitive performance were calculated using logistic regression analysis.

RESULTS

Of the young patients with stroke, 41% experienced symptoms of fatigue, versus 18.4% in controls (p 0.0005). Fatigue was associated with a poor functional outcome, as assessed by the mRS (OR 4.0 (95% CI 1.6 to 9.6), IADL (OR 2.2 (95% CI 1.1 to 4.6), and impairment in speed of information processing (OR 2.2 (95% CI 1.3 to 3.9).

CONCLUSIONS

Fatigue was very common in young stroke survivors and was associated with a poor functional outcome, even after almost a decade of follow-up.

Cognitive function, depression, fatigue and quality of life among long-term survivors of head and neck cancer

Background

Long-term cancer treatment complications become more prevalent as survival improves. Little is known about the psychological complications in long-term survivors of head and neck cancer (HNC). We investigated cognitive functioning and its relation with depression, fatigue, cognitive complaints, and brain lesions on MRI.

Methods

This study is part of a multicentre, prospective cohort study of 65 patients treated for HNC. A comprehensive neuropsychological assessment was combined with validated questionnaires on subjective memory complaints, depression, and fatigue after a median of 7 years follow-up. Results were compared with age- and education-adjusted normative data. Further, we evaluated cerebral white matter hyperintensities (WMH), brain volume, and infarctions on MRI.

Results

HNC patients had worse cognitive performance in two of the five assessed cognitive domains: episodic memory (z = -0.48, P = .003) and speed of information processing (z = -0.47, P < 0.001). Patients with fatigue performed worse than patients without fatigue on verbal fluency (mean difference in z-score 0.52, P = .02) and speed of information processing (0.49, P = .04). Patients with subjective memory complaints had a worse episodic memory performance (mean difference in z-score -0.96; P = .02). Patients with cerebral infarction(s) on MRI performed worse on fluency (mean difference in z-score 0.74, P = .005). A lower cognitive performance was not associated with depression, WMH or brain volume.

Conclusion

Long-term HNC survivors showed worse cognitive functioning 7 years after treatment. Cognitive function was associated with subjective complaints and fatigue, but not with depressive symptoms. Cerebral infarctions on MRI were correlated with cognitive function, whereas WMH, and brain volume were not.

Poststroke Epilepsy Is Associated With a High Mortality After a Stroke at Young Age: Follow-Up of Transient Ischemic Attack and Stroke Patients and Unelucidated Risk Factor Evaluation Study

BACKGROUND AND PURPOSE

Poststroke epilepsy is a common complication after a young stroke. We investigated the association between poststroke epilepsy and mortality.

METHODS

We performed a prospective cohort study among 631 patients with a first-ever transient ischemic attack or ischemic stroke, aged 18 to 50 years. Survival analysis and Cox proportional hazard analysis were used to estimate cumulative mortality and hazard ratios for patients with and without epilepsy.

RESULTS

After mean follow-up of 12.5 years (SD 8.6), 76 (12.0%) developed poststroke epilepsy. Case fatality was 27.4% for patients with poststroke epilepsy and 2.1% for those without. Poststroke epilepsy was associated with 30-day mortality (hazard ratio, 4.8; 95% confidence interval, 1.7-14.0) and long-term mortality (hazard ratio, 1.8; 95% confidence interval, 1.2-2.9).

CONCLUSIONS

Epilepsy is a common problem after a young stroke and is associated with an increased short-term and long-term mortality.

White matter integrity and depressive symptoms in cerebral small vessel disease: The RUN DMC study

OBJECTIVE

Depressive symptoms are common in elderly with cerebral small vessel disease (SVD). As not every individual with SVD experiences depressive symptoms, other factors might play a role. We therefore investigated the white matter (WM) integrity of the white matter tracts in elderly with depressive symptoms, independent of global cognitive function, by applying the tract-based spatial statistics (TBSS).

DESIGN

Prospective cohort study with cross-sectional baseline data.

SETTING

Radboud University Nijmegen Medical Centre, The Netherlands.

PARTICIPANTS

438 individuals aged between 50-85 years, with SVD without dementia.

MEASUREMENTS

Diffusion tensor imaging parameters and depressive symptoms, assessed with the Center for Epidemiologic Studies Depression Scale.

RESULTS

Compared with non-depressed participants (N = 287), those with depressive symptoms (N = 151) had lower fractional anisotropy in the genu and body of the corpus callosum, bilateral inferior fronto-occipital fasciculus, uncinate fasciculus, and corona radiata. These differences disappeared after adjustment for white matter hyperintensities (WMH) and lacunar infarcts. Mean-, axial- and radial diffusivity were higher in these areas in participants with depressive symptoms. After additional adjustment for WMH and lacunar infarcts, the changes observed in radial diffusivity also disappeared. Adding global cognition as confounding variable altered the diffusion parameters only slightly.

CONCLUSION

This study indicates that elderly with depressive symptoms show a lower WM integrity, independent of global cognitive function, and that the presence of SVD is mostly responsible, affecting the fronto-subcortical regions and hereby disrupting the neural circuitry involved in mood regulation.

Magnetic resonance imaging of the carotid artery in long-term head and neck cancer survivors treated with radiotherapy

BACKGROUND

In head and neck cancer (HNC) patients, long-term treatment-related complications include radiotherapy (RT)-induced carotid vasculopathy and stroke. The current study investigated the magnetic resonance imaging (MRI) characteristics of the carotid wall in long-term HNC survivors treated with RT.

METHODS

MRI of the carotid arteries was performed within a prospective cohort of 42 HNC patients on average 7 years after RT. Two independent radiologists assessed maximal vessel wall thickness of common and internal carotid arteries. In case of wall thickening (≥ 2 mm) the MRI signals as well as length of the thickened segment were assessed.

RESULTS

Mean (SD) age of the 42 patients at baseline was 53 (13) years and mean (SD) follow-up time after RT was 6.8 (1.3) years. In total 62% were men and 60% had one or more cerebrovascular risk factors. Mean (SD) dose of RT on the common carotid arteries and internal carotid arteries was 57 Gy (11) and 61 Gy (10), respectively. Wall thickening was observed in 58% of irradiated versus 27% of non-irradiated common carotid arteries and 24% of irradiated versus 6% of non-irradiated internal carotid arteries (p < 0.05). Mean (SD) thickness of the irradiated and non-irradiated common carotid arteries was 2.5 (0.9) and 2 (0.7) mm (p = 0.02). Mean thickness of the irradiated and non-irradiated internal carotid arteries was 1.8 (0.8) and 1.5 mm (0.3) (n.s.). Mean length of the thickened vessel wall was 48 mm versus 36 mm in the irradiated versus non-irradiated common carotid arteries (p = 0.03) and 20 mm versus 15 mm in the irradiated versus non-irradiated internal carotid arteries (n.s.). No significant differences were observed for signal intensities of the vessel walls.

CONCLUSIONS

Our study showed significantly more vessel wall thickening in irradiated versus non-irradiated carotid arteries years after RT for HNC, while no differences in signal intensities were observed.

Cohort study ON Neuroimaging, Etiology and Cognitive consequences of Transient neurological attacks (CONNECT): study rationale and protocol

Background

Transient ischemic attacks (TIA) are characterized by acute onset focal neurological symptoms and complete recovery within 24 hours. Attacks of nonfocal symptoms not fulfilling the criteria for TIA but lacking a clear alternative diagnosis are called transient neurological attacks (TNA). Although TIA symptoms are transient in nature, cognitive complaints may persist. In particular, attacks consisting of both focal and nonfocal symptoms (mixed TNA) have been found to be associated with an increased risk of dementia. We aim to study the prevalence, etiology and risk factors of cognitive impairment after TIA or TNA.

Methods/Design

CONNECT is a prospective cohort study on cognitive function after TIA and TNA. In total, 150 patients aged ≥45 years with a recent (<7 days after onset) TIA or TNA and no history of stroke or dementia will be included. We will classify events as: TIA, nonfocal TNA, or mixed TNA. Known short lasting paroxysmal neurological disorders like migraine aura, seizures and Ménière disease are excluded from the diagnosis of TNA. Patients will complete a comprehensive neuropsychological assessment and undergo MRI <7 days after the qualifying event and again after six months. The primary clinical outcomes will be cognitive function at baseline and six months after the primary event. Imaging outcomes include the prevalence and evolution of DWI lesions, white matter hyperintensities and lacunes, as well as resting state networks functionality and white matter microstructural integrity. Differences between types of event and DWI, as well as determinants of both clinical and imaging outcomes, will be assessed.

Discussion

CONNECT can provide insight in the prevalence, etiology and risk factors of cognitive impairment after TIA and TNA and thereby potentially identify a new group of patients at increased risk of cognitive impairment.

Ipsilateral hippocampal atrophy is associated with long-term memory dysfunction after ischemic stroke in young adults

Memory impairment after stroke in young adults is poorly understood. In elderly stroke survivors memory impairments and the concomitant loss of hippocampal volume are usually explained by coexisting neurodegenerative disease (e.g., amyloid pathology) in interaction with stroke. However, neurodegenerative disease, such as amyloid pathology, is generally absent at young age. Accumulating evidence suggests that infarction itself may cause secondary neurodegeneration in remote areas. Therefore, we investigated the relation between long-term memory performance and hippocampal volume in young patients with first-ever ischemic stroke. We studied all consecutive first-ever ischemic stroke patients, aged 18-50 years, admitted to our academic hospital center between 1980 and 2010. Episodic memory of 173 patients was assessed using the Rey Auditory Verbal Learning Test and the Rey Complex Figure and compared with 87 stroke-free controls. Hippocampal volume was determined using FSL-FIRST, with manual correction. On average 10 years after stroke, patients had smaller ipsilateral hippocampal volumes compared with controls after left-hemispheric stroke (5.4%) and right-hemispheric stroke (7.7%), with most apparent memory dysfunctioning after left-hemispheric stroke. A larger hemispheric stroke was associated with a smaller ipsilateral hippocampal volume (b=-0.003, P<0.0001). Longer follow-up duration was associated with smaller ipsilateral hippocampal volume after left-hemispheric stroke (b=-0.028 ml, P=0.002) and right-hemispheric stroke (b=-0.015 ml, P=0.03). Our results suggest that infarction is associated with remote injury to the hippocampus, which may lower or expedite the threshold for cognitive impairment or even dementia later in life.

Cardiovascular Disease Is the Main Cause of Long-Term Excess Mortality After Ischemic Stroke in Young Adults

Adults with stroke at a young age (18–50 years) remain at an increased risk of death for decades. It is unclear what cause underlies this long-term excess mortality and whether this is sex and time specific. Therefore, we investigated sex-specific temporal changes in cause of death after transient ischemic attack or ischemic stroke in young adults aged 18 to 50 years. We included all 845 consecutive 30-day survivors, of a first-ever transient ischemic attack (n=261) or ischemic stroke (n=584), admitted to our hospital between 1980 and 2010. Survival status was assessed at April 1, 2013. Observed cause-specific mortality was compared with expected mortality, derived from mortality rates in the general population with similar age, sex, and calendar-year characteristics. During a median follow-up of 9.2 years, 146 patients (17.3%) died, such that 29 years of life was lost by each individual. For all causes of death, observed mortality exceeded expected mortality. The absolute excess risk of death was for 74% attributable to a vascular cause (absolute excess risk, 2.8 per 1000 person-years [95% confidence interval, 1.8–4.1] for stroke and absolute excess risk, 4.3 per 1000 person-years [95% confidence interval, 2.9–5.9] for other vascular causes). The absolute excess risk was highest between 10 and 15 years after stroke and this peak was most pronounced in men and mainly attributable to vascular death. Long-term excess death after stroke in young adults is mainly attributable to a vascular cause and most pronounced in men. Attempts to reduce the risk of vascular disease after stroke in young adults should extend beyond the acute phase into the long term.

White matter integrity in small vessel disease is related to cognition

Cerebral small vessel disease, including white matter hyperintensities (WMH) and lacunes of presumed vascular origin, is common in elderly people and is related to cognitive impairment and dementia. One possible mechanism could be the disruption of white matter tracts (both within WMH and normal-appearing white matter) that connect distributed brain regions involved in cognitive functions. Here, we investigated the relation between microstructural integrity of the white matter and cognitive functions in patients with small vessel disease. The Radboud University Nijmegen Diffusion tensor and Magnetic resonance Cohort study is a prospective cohort study among 444 independently living, non-demented elderly with cerebral small vessel disease, aged between 5500 and 85 years. All subjects underwent magnetic resonance imaging and diffusion tensor imaging scanning and an extensive neuropsychological assessment. We showed that loss of microstructural integrity of the white matter at specific locations was related to specific cognitive disturbances, which was mainly located in the normal-appearing white matter (p < 0.05, FWE-corrected for multiple comparisons). The microstructural integrity in the genu and splenium showed the highest significant relation with global cognitive function and executive functions, in the cingulum bundle with verbal memory performance. Associations between diffusion tensor imaging parameters and most cognitive domains remained present after adjustment for WMH and lacunes. In conclusion, cognitive disturbances in subjects with cerebral small vessel disease are related to microstructural integrity of multiple white matter fibers (within WMH and normal-appearing white matter) connecting different cortical and subcortical regions.

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White matter integrity in small vessel disease (SVD) was assessed with DTI.

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White matter integrity was related to cognition independent of SVD-markers.

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This relation was seen in multiple fibers within white matter hyperintensities.

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But also in normal-appearing white matter connecting different (sub)cortical regions