Sex Differences in Care and Long-Term Mortality After Stroke: Australian Stroke Clinical Registry.

Introduction: There is some evidence that women receive evidence-based care less often than men, but how this influences long-term mortality after stroke is unclear. We explored this issue using data from a national stroke registry. Materials and Methods: Data are first-ever hospitalized strokes (2010-2014) in the Australian Stroke Clinical Registry from 39 hospitals linked to the national death registrations. Multilevel Poisson regression was used to estimate the women:men mortality rate ratio (MRR), with adjustment for sociodemographics, stroke severity, and processes of care (stroke unit care, intravenous thrombolysis, antihypertensive agent[s], and discharge care plan). Results: Among 14,118 events (46% females), women were 7 years older and had greater baseline severity compared to men (29% vs. 37%; p < 0.001), but there were no differences in the four processes of care available across hospitals. In the whole cohort, 1-year mortality was greater in women than men (MRRunadjusted 1.44, 95% confidence interval [CI] 1.34-1.54). However, there were no differences after adjusting for age and stroke severity (MRRadjusted 1.03, 95% CI 0.95-1.10). In analyses of additional processes from Queensland hospitals (n = 5224), women were less often administered aspirin ≤48 hours (61% vs. men 69%, p < 0.015). In Queensland hospitals, there were no statistically significant sex differences in 1-year mortality after adjusting for age, stroke severity, and early administration of aspirin. Conclusion: Greater mortality in women can be explained by differences in age and stroke severity. This highlights the importance of better management of risk factors in the elderly and, potentially, the need for greater access to early aspirin for women with stroke.

Weekend hospital discharge is associated with suboptimal care and outcomes: An observational Australian Stroke Clinical Registry study.

BACKGROUND: The quality of stroke care may diminish on weekends. AIMS: We aimed to compare the quality of care and outcomes for patients with stroke/transient ischemic attack discharged on weekdays compared with those discharged on weekends. METHODS: Data from the Australian Stroke Clinical Registry from January 2010 to December 2015 (n = 45 hospitals) were analyzed. Differences in processes of care by the timing of discharge are described. Multilevel regression and survival analyses (up to 180 days postevent) were undertaken. RESULTS: Among 30,649 registrants, 2621 (8.6%) were discharged on weekends (55% male; median age 74 years). Compared to those discharged on weekdays, patients discharged on weekends were more often patients with a transient ischemic attack (weekend 35% vs. 19%; p < 0.001) but were less often treated in a stroke unit (69% vs. 81%; p < 0.001), prescribed antihypertensive medication at discharge (65% vs. 71%; p < 0.001) or received a care plan if discharged to the community (47% vs. 53%; p < 0.001). After accounting for patient characteristics and clustering by hospital, patients discharged on weekends had a 1 day shorter length of stay (coefficient = -1.31, 95% confidence interval [CI] = -1.52, -1.10), were less often discharged to inpatient rehabilitation (aOR = 0.39, 95% CI = 0.34, 0.44) and had a greater hazard of death within 180 days (hazard ratio = 1.22, 95% CI = 1.04, 1.42) than those discharged on weekdays. CONCLUSIONS: Patients with stroke/transient ischemic attack discharged on weekends were more likely to receive suboptimal care and have higher long-term mortality. High quality of stroke care should be consistent irrespective of the timing of hospital discharge.

LC3 Immunostaining in the Inferior Olivary Nuclei of Cats With Niemann-Pick Disease Type C1 Is Associated With Patterned Purkinje Cell Loss.

The feline model of Niemann-Pick disease, type C1 (NPC1) recapitulates the clinical, neuropathological, and biochemical abnormalities present in children with NPC1. The hallmarks of disease are the lysosomal storage of unesterified cholesterol and multiple sphingolipids in neurons, and the spatial and temporal distribution of Purkinje cell death. In feline NPC1 brain, microtubule-associated protein 1 light chain 3 (LC3) accumulations, indicating autophagosomes, were found within axons and presynaptic terminals. High densities of accumulated LC3 were seen in subdivisions of the inferior olive, which project to cerebellar regions that show the most Purkinje cell loss, suggesting that autophagic abnormalities in specific climbing fibers may contribute to the spatial pattern of Purkinje cell loss seen. Biweekly intrathecal administration of 2-hydroxypropyl-beta cyclodextrin (HPßCD) ameliorated neurological dysfunction, reduced cholesterol and sphingolipid accumulation, and increased lifespan in NPC1 cats. LC3 pathology was reduced in treated animals suggesting that HPßCD administration also ameliorates autophagic abnormalities. This study is the first to (i) identify specific brain regions exhibiting autophagic abnormalities in any species with NPC1, (ii) provide evidence of differential vulnerability among discrete brain nuclei and pathways, and (iii) show the amelioration of these abnormalities in NPC1 cats treated with HPßCD.

Treatment and Outcomes of Working Aged Adults with Stroke: Results from a National Prospective Registry.

BACKGROUND: Given the potential differences in etiology and impact, the treatment and outcome of younger patients (aged 18-64 years) require examination separately to older adults (aged ≥65 years) who experience acute stroke. METHODS: Data from the Australian Stroke Clinical Registry (2010-2015) including demographic and clinical characteristics, provision of evidence-based therapies and health-related quality of life (HRQoL) post-stroke was used. Descriptive statistics and multilevel regression models were used for group comparisons. RESULTS: Compared to older patients (age ≥65 years) among 26,220 registrants, 6,526 (25%) younger patients (age 18-64 years) were more often male (63 vs. 51%; p < 0.001), born in Australia (70 vs. 63%; p < 0.001), more often discharged home from acute care (56 vs. 38%; p < 0.001), and less likely to receive antihypertensive medication (61 vs. 73%; p < 0.001). Younger patients had a 74% greater odds of having lower HRQoL compared to an equivalent aged-matched general population (adjusted OR 1.74, 95% CI 1.56-1.93, p < 0.001). CONCLUSIONS: Younger stroke patients exhibited distinct differences from their older counterparts with respect to demographic and clinical characteristics, prescription of antihypertensive medications and residual health status.

Transitioning from a single-site pilot project to a state-wide regional telehealth service: The experience from the Victorian Stroke Telemedicine programme.

Scaling of projects from inception to establishment within the healthcare system is rarely formally reported. The Victorian Stroke Telemedicine (VST) programme provided a very useful opportunity to describe how rural hospitals in Victoria were able to access a network of Melbourne-based neurologists via telemedicine. The VST programme was initially piloted at one site in 2010 and has gradually expanded as a state-wide regional service operating with 16 hospitals in 2017. The aim of this paper is to summarise the factors that facilitated the state-wide transition of the VST programme. A naturalistic case-study was used and data were obtained from programme documents, e.g. minutes of governance committees, including the steering committee, the management committee and six working groups; operational and evaluation documentation, interviews and research field-notes taken by project staff. Thematic analysis was undertaken, with results presented in narrative form to provide a summary of the lived experience of developing and scaling the VST programme. The main success factors were attaining funding from various sources, identifying a clinical need and evidence-based solution, engaging stakeholders and facilitating co-design, including embedding the programme within policy, iterative evaluation including performing financial sustainability modelling, and conducting dissemination activities of the interim results, including promotion of early successes.

Strategic framework improves access to stroke reperfusion across the state of Victoria Australia.

BACKGROUND: In 2010, rapid access to stroke thrombolysis centres was limited in some regional areas in the Australian state of Victoria. These results, and planning for endovascular clot retrieval (ECR), have led to the implementation of strategies by the Victorian Stroke Clinical Network, the Victorian Stroke Telemedicine Program and local health services to improve state-wide access. AIMS: To examine whether access to stroke reperfusion services (thrombolysis and ECR) in regional Victoria have subsequently improved. METHODS: The locations of suspected stroke patients attended by ambulance in 2015 were mapped, and drive times to the nearest reperfusion services were calculated. We then calculated the proportion of cases with transport times within: (i) 60 min to thrombolysis centres; and (ii) 180 min to two ECR centres designated to receive regional patients. Statistical comparisons to existing 2010 data were made. RESULTS: In 2015, Ambulance Victoria attended 16 418 cases of suspected stroke (2.9% of all emergency calls), of whom 4597 (28%) were located in regional Victoria. Compared to 2010, a greater proportion of regional suspected stroke patients in 2015 were located within 60 min of a thrombolysis centre by road (77-95%, P < 0.001). A 3-h road travel time to the two ECR centres is currently possible for 88% of regional patients. CONCLUSION: A strategic and region-specific approach has resulted in improved access by road transport to reperfusion therapies for stroke patients across Victoria.

Deconstruction of Interhospital Transfer Workflow in Large Vessel Occlusion: Real-World Data in the Thrombectomy Era.

BACKGROUND AND PURPOSE: Interhospital transfer is a critical component in the treatment of acute anterior circulation large vessel occlusive stroke transferred for mechanical thrombectomy. Real-world data for benchmarking and theoretical modeling are limited. We sought to characterize transfer workflow from primary stroke center (PSC) to comprehensive stroke center after the publication of positive thrombectomy trials. METHODS: Consecutive patients transferred from 3 high-volume PSCs to a single comprehensive stroke center between January 2015 and August 2016 were included in a retrospective study. Factors associated with key time metrics were analyzed with emphasis on PSC intrahospital workflow. RESULTS: Sixty-seven patients were identified. Median age was 74 years (interquartile range [IQR], 63.5-78) and National Institutes of Health Stroke Scale 17 (IQR, 12-21). Median transfer time measured by PSC-door-to-comprehensive stroke center-door was 128 minutes (IQR, 107-164), of which 82.8% was spent at PSCs (door-in-door-out [DIDO]; 106 minutes; IQR, 86-143). The lengthiest component of DIDO was computed-tomography-to-retrieval-request (median 59.5 minutes; IQR, 44-83). The 37.3% had DIDO exceeding 120 minutes. DIDO times differed significantly between PSCs (P=0.01). In multivariate analyses, rerecruiting the initial ambulance crew for transfer (P<0.01) and presentation during working hours (P=0.04) were associated with shorter DIDO times. CONCLUSIONS: In a metropolitan hub-and-spoke network, PSC-door-to-comprehensive stroke center-door and DIDO times are long even in high-volume PSCs. Improving PSC workflow represents a major opportunity to expedite mechanical thrombectomy and improve patient outcomes.

Risk-adjusted hospital mortality rates for stroke: evidence from the Australian Stroke Clinical Registry (AuSCR).

OBJECTIVES: Hospital data used to assess regional variability in disease management and outcomes, including mortality, lack information on disease severity. We describe variance between hospitals in 30-day risk-adjusted mortality rates (RAMRs) for stroke, comparing models that include or exclude stroke severity as a covariate. DESIGN: Cohort design linking Australian Stroke Clinical Registry data with national death registrations. Multivariable models using recommended statistical methods for calculating 30-day RAMRs for hospitals, adjusted for demographic factors, ability to walk on admission, stroke type, and stroke recurrence. SETTING: Australian hospitals providing at least 200 episodes of acute stroke care, 2009-2014. MAIN OUTCOME MEASURES: Hospital RAMRs estimated by different models. Changes in hospital rank order and funnel plots were used to explore variation in hospital-specific 30-day RAMRs; that is, RAMRs more than three standard deviations from the mean. RESULTS: In the 28 hospitals reporting at least 200 episodes of care, there were 16 218 episodes (15 951 patients; median age, 77 years; women, 46%; ischaemic strokes, 79%). RAMRs from models not including stroke severity as a variable ranged between 8% and 20%; RAMRs from models with the best fit, which included ability to walk and stroke recurrence as variables, ranged between 9% and 21%. The rank order of hospitals changed according to the covariates included in the models, particularly for those hospitals with the highest RAMRs. Funnel plots identified significant deviation from the mean overall RAMR for two hospitals, including one with borderline excess mortality. CONCLUSIONS: Hospital stroke mortality rates and hospital performance ranking may vary widely according to the covariates included in the statistical analysis.

Exploring the benefits of a stroke telemedicine programme: An organisational and societal perspective.

We undertook a qualitative analysis to identify the broader benefits of a state-wide acute stroke telemedicine service beyond the patient-clinician consultation. Since 2010, the Victorian Stroke Telemedicine (VST) programme has provided a clinical service for regional hospitals in Victoria, Australia. The benefits of the Victorian Stroke Telemedicine programme were identified through document analysis of governance activities, including communications logs and reports from hospital co-ordinators of the programme. Discussions with the Victorian Stroke Telemedicine management were undertaken and field notes were also reviewed. Several benefits of telemedicine were identified within and across participating hospitals, as well as for the state government and community. For hospitals, standardisation of clinical processes was reported, including improved stroke care co-ordination. Capacity building occurred through professional development and educational workshops. Enhanced networking, and resource sharing across hospitals was achieved between hospitals and organisations. Governments leveraged the Victorian Stroke Telemedicine programme infrastructure to provide immediate access to new treatments for acute stroke care in regional areas. Standardised data collection allowed routine quality of care monitoring. Community awareness of stroke symptoms occurred with media reports on the novel technology and improved patient outcomes. The value of telemedicine services extends beyond those involved in the clinical consultation to healthcare funders and the community.

Intravenous thrombolysis for acute ischaemic stroke in the setting of rivaroxaban use.

The risk of thrombolysis in patients taking novel anticoagulants remains unclear. We describe a patient with a large acute ischaemic stroke, who had a low calibrated anti-factor Xa level, who safely received thrombolysis 15-17 hours after standard dose rivaroxaban without subsequent intracerebral haemorrhage.

Differing associations of white matter lesions and lacunar infarction with retinal microvascular signs.

BACKGROUND: White matter lesions (WML) and lacunar infarcts (LI) are believed to have microvascular etiologies but the exact microvascular changes occurring in each is unclear. AIM: Using the retina as a proxy, we assessed retinal microvascular changes in WML and LI. METHODS: We prospectively recruited 1211 acute stroke patients. Four subgroups were identified from neuroimaging: WML alone, LI alone, both WML and LI, neither WML nor LI. Masked retinal photographs identified retinopathy and retinal arteriolar wall signs and measured retinal vascular caliber. RESULTS: Compared with 448 controls with neither WML nor LI, 384 patients with only WML were more likely to have retinopathy [odds ratio (OR) 1·5, 95% confidence interval (CI) 1·1 to 2·1] and enhanced arteriolar light reflex (OR 1·6, 95% CI 1·1 to 2·3); 200 patients with only LI were more likely to have arteriolar narrowing (OR 1·6, 95% CI 1·1 to 2·3) and enhanced arteriolar light reflex (OR 1·6, 95% CI 1·0 to 2·4); and 179 patients with both WML and LI were more likely to have arteriovenous nicking (OR 1·7, 95% CI 1·1 to 2·6), enhanced arteriolar light reflex (OR 2·0, 95% CI 1·3 to 3·2) and wider venules (OR 2·3, 95% CI 1·4 to 3·6). All analyses were adjusted for age, gender, study site and cardiovascular risk factors. CONCLUSION: Both WML and LI were associated with retinal microvascular signs, supporting a microvascular etiology. Differing patterns of association suggest different mechanisms may predominate, e.g. greater endothelial permeability in WML, and ischemia associated with arteriolar wall disease in LI.

Helsinki model cut stroke thrombolysis delays to 25 minutes in Melbourne in only 4 months.

OBJECTIVE: To test the transferability of the Helsinki stroke thrombolysis model that achieved a median 20-minute door-to-needle time (DNT) to an Australian health care setting. METHODS: The existing "code stroke" model at the Royal Melbourne Hospital was evaluated and restructured to include key components of the Helsinki model: 1) ambulance prenotification with patient details alerting the stroke team to meet the patient on arrival; 2) patients transferred directly from triage onto the CT table on the ambulance stretcher; and 3) tissue plasminogen activator (tPA) delivered in CT immediately after imaging. We analyzed our prospective, consecutive tPA registry for effects of these protocol changes on our DNT after implementation during business hours (8 am to 5 pm Monday-Friday) from May 2012. RESULTS: There were 48 patients treated with tPA in the 8 months after the protocol change. Compared with 85 patients treated in 2011, the median (interquartile range) DNT was reduced from 61 (43-75) minutes to 46 (24-79) minutes (p = 0.040). All of the effect came from the change in the in-hours DNT, down from 43 (33-59) to 25 (19-48) minutes (p = 0.009), whereas the out-of-hours delays remain unchanged, from 67 (55-82) to 62 (44-95) minutes (p = 0.835). CONCLUSION: We demonstrated rapid transferability of an optimized tPA protocol to a different health care setting. With the cooperation of ambulance, emergency, and stroke teams, we succeeded in the absence of a dedicated neurologic emergency department or electronic patient records, which are features of the Finnish system. The next challenge is providing the same service out-of-hours.

Do patients who take part in stroke research differ from non-participants? Implications for generalizability of results.

BACKGROUND: Stroke is one of the most disabling neurological conditions. Clinical research is vital for expanding knowledge of treatment effectiveness among stroke patients. However, evidence begins to accumulate that stroke patients who take part in research represent only a small proportion of all stroke patients. Research participants may also differ from the broader patient population in ways that could potentially distort treatment effects reported in therapeutic trials. The aims of this study were to estimate the proportion of stroke patients who take part in clinical research studies and to compare demographic and clinical profiles of research participants and non-participants. METHODS: 5,235 consecutive patients admitted to the Stroke Care Unit of the Royal Melbourne Hospital, Melbourne, Australia, for stroke or transient ischaemic attack between January 2004 and December 2011 were studied. The study used cross-sectional design. Information was collected on patients' demographic and socio-economic characteristics, risk factors, and comorbidities. Associations between research participation and patient characteristics were initially assessed using χ(2) or Mann-Whitney tests, followed by a multivariable logistic regression analysis. The logistic regression analysis was carried out using generalised estimating equations approach, to account for patient readmissions during the study period. RESULTS: 558 Stroke Care Unit patients (10.7%) took part in at least one of the 33 clinical research studies during the study period. Transfer from another hospital (OR = 0.35, 95% CI 0.22-0.55), worse premorbid function (OR = 0.61, 95% CI 0.54-0.70), being single (OR = 0.61, 95% CI 0.44-0.84) or widowed (OR = 0.77, 95% CI 0.60-0.99), non-English language (OR = 0.67, 95% CI 0.53-0.85), high socio-economic status (OR = 0.74, 95% CI 0.59-0.93), residence outside Melbourne (OR = 0.75, 95% CI 0.60-0.95), weekend admission (OR = 0.78, 95% CI 0.64-0.94), and a history of atrial fibrillation (OR = 0.79, 95% CI 0.63-0.99) were associated with lower odds of research participation. A history of hypertension (OR = 1.50, 95% CI 1.08-2.07) and current smoking (OR = 1.23, 95% CI 1.01-1.50) on the other hand were associated with higher odds of research participation. CONCLUSIONS: The results of this study indicate that stroke patients who take part in clinical research do not represent 'typical' patient admitted to a stroke unit. The imbalance of prognostic factors between stroke participants and non-participants has serious implications for interpretation of research findings reported in stroke literature. This study provides insights into clinical, demographic, and socio-economic characteristics of stroke patients that could potentially be targeted to enhance generalizability of stroke research studies. Given the imbalance of prognostic factors between research participants and non-participants, future studies need to examine differences in stroke outcomes of these groups of patients.

CT perfusion improves diagnostic accuracy and confidence in acute ischaemic stroke.

BACKGROUND AND OBJECTIVE: CT perfusion (CTP) is rapid and accessible for emergency ischaemic stroke diagnosis. The feasibility of introducing CTP and diagnostic accuracy versus non-contrast CT (NCCT) in a tertiary hospital were assessed. METHODS: All patients presenting <9 h from stroke onset or with wake-up stroke were eligible for CTP (Siemens 16-slice scanner, 2×24 mm slabs) unless they had estimated glomerular filtration rate (eGFR)<50 ml/min or diabetes with unknown eGFR. NCCT was assessed by a radiologist and stroke neurologist for early ischaemic change and hyperdense arteries. CTP was assessed for prolonged time to peak and reduced cerebral blood flow. Technical adequacy was defined as 2 CTP slabs of sufficient quality to diagnose stroke. RESULTS: Between January 2009 and September 2011, 1152 ischaemic stroke patients were admitted, 475 (41%) were <9 h/wake-up onset. Of these, 276 (58%) had CTP. Reasons for not performing CTP were diabetes with unknown eGFR (48 (10%)), known kidney disease (36 (8%)), established infarct on NCCT (27 (6%)), posterior circulation syndrome (25 (5%)) and patient motion/instability (16 (3%)). Clinician discretion excluded a further 47 (10%). CTP was more frequently diagnostic than NCCT (80% vs 50%, p<0.001). Non-diagnostic CTP was due to lacunar infarction (28 (10%)), infarct outside slab coverage (21 (8%)), technical failure (4 (1%)) and reperfusion (2 (0.7%)). Normal CTP in 86/87 patients with stroke mimics supported withholding tissue plasminogen activator. CTP technical adequacy improved from 56% to 86% (p<0.001) after the first 6 months. Median time for NCCT/CTP/arch-vertex CT angiogram (including processing and interpretation) was 12 min. No clinically significant contrast nephropathy occurred. CONCLUSIONS: CTP in suspected stroke is widely applicable, rapid and increases diagnostic confidence.

Transient ischemic attack and acute ischemic stroke: associations with retinal microvascular signs.

BACKGROUND AND PURPOSE: Small vessel disease plays a role in cerebral events. We aimed to investigate the prevalence and patterns of retinal microvascular signs (surrogates for cerebral small vessel disease) among patients with transient ischemic attack (TIA) or acute stroke and population control subjects. METHODS: Patients with TIA or acute stroke aged ≥49 years admitted to hospitals in Melbourne and Sydney, Australia, were recruited to the Multi-Centre Retina and Stroke Study (n=693, 2005 to 2007). Control subjects were Blue Mountains Eye Study participants aged ≥49 years without TIAs or stroke (n=3384, 1992 to 1994, west of Sydney). TIA, ischemic stroke, or primary intracerebral hemorrhage was classified using standardized neurological assessments, including neuroimaging. Retinal microvascular signs (retinopathy, focal arteriolar narrowing, arteriovenous nicking, enhanced arteriolar light reflex) were assessed from retinal photographs masked to clinical information. RESULTS: Patients with TIA or acute stroke were older than control subjects and more likely to have stroke risk factors. After adjustment for study site and known risk factors, all retinal microvascular signs were more common in patients with TIA or acute stroke than in control subjects (OR, 1.9 to 8.7; P<0.001). Patients with TIA and those with ischemic stroke had similar prevalences of nondiabetic retinopathy (26.9% versus 29.5%; OR, 0.8; 95% CI, 0.5 to 1.6), diabetic retinopathy (55.5% versus 50.0%; OR, 1.3; 95% CI, 0.4 to 3.6), focal arteriolar narrowing (15.6% versus 18.4%; OR, 0.8; 95% CI, 0.4 to 1.5), and arteriovenous nicking (23.0% versus 17.8%; OR, 1.4; 95% CI, 0.7 to 2.7). CONCLUSIONS: Patients with TIA and acute stroke may share similar risk factors or pathogenic mechanisms.

Retinopathy and lobar intracerebral hemorrhage: insights into pathogenesis.

BACKGROUND: The vascular pathogenesis underlying lobar intracerebral hemorrhage (ICH) is unclear. OBJECTIVE: To determine whether certain retinal microvascular signs are associated with lobar ICH to improve understanding of its underlying cerebral vasculopathy. DESIGN: Prospective cohort study. SETTING: Royal Melbourne Hospital and Westmead Hospital. PATIENTS: Of 655 patients with acute stroke, 25 had lobar ICH, 51 had deep ICH, 93 had lacunar infarction, and 486 had nonlacunar cerebral infarction. MAIN OUTCOME MEASURES: Retinal photographs were assessed for retinopathy lesions (microaneurysms, retinal hemorrhages, cotton-wool spots, and hard exudates) and retinal arteriolar wall signs (focal arteriolar narrowing, arteriovenous nicking, and enhanced arteriolar wall light reflex) masked to the cerebral pathologic abnormalities and the study hypothesis. RESULTS: In patients without diabetes mellitus, retinopathy lesions were more likely to be present in persons with lobar ICH than in those with either lacunar infarction (47.8% vs 30.4%; adjusted odds ratio, 3.5; 95% confidence interval, 1.1-10.9) or nonlacunar cerebral infarction (47.8% vs 24.6%; 3.3;1.4-8.1). Most retinal arteriolar wall signs were less frequent in lobar ICH than in deep ICH, although this difference was significant only for focal arteriolar narrowing. CONCLUSIONS: Patients with lobar ICH were more likely than patients with lacunar or nonlacunar cerebral infarction to have retinopathy lesions, suggesting breakdown of the blood-retina barrier in patients with lobar ICH. These findings support a distinct vasculopathy in lobar ICH compared with other acute stroke subtypes resulting from cerebral small vessel disease or ischemic infarction.

Differential associations of cortical and subcortical cerebral atrophy with retinal vascular signs in patients with acute stroke.

BACKGROUND AND PURPOSE: The relationship of cortical and subcortical cerebral atrophy to cerebral microvascular disease is unclear. We aimed to assess the associations of retinal vascular signs with cortical and subcortical atrophy in patients with acute stroke. METHODS: In the Multi-Centre Retinal Stroke Study, 1360 patients with acute stroke admitted to 2 Australian and 1 Singaporean tertiary hospital during 2005 to 2007 underwent neuroimaging and retinal photography. Cortical and subcortical cerebral atrophy were graded based on standard CT scans. A masked assessment of retinal photographs identified focal retinal vascular signs, including retinopathy and retinal arteriolar wall signs (ie, focal arteriolar narrowing, arteriovenous nicking, arteriolar wall light reflex) and measured quantitative signs (retinal arteriolar and venular caliber). RESULTS: After adjusting for age, gender, study site, hypertension, hypercholesterolemia, diabetes, and smoking status, none of the retinal vascular signs assessed were associated with cortical atrophy, whereas retinopathy (OR, 1.9; CI, 1.2 to 3.0) and enhanced arteriolar light reflex (OR, 2.0; CI, 1.2 to 3.2) were significantly associated with subcortical atrophy. CONCLUSIONS: Our finding that certain retinal vascular signs are associated with subcortical but not cortical atrophy, suggests a differential pathophysiology between these 2 cerebral atrophy subtypes and a potential role for small vessel disease underlying subcortical cerebral atrophy.

Brain imaging in transient ischemic attack--redefining TIA.

Transient ischemic attack (TIA) has recently been redefined to incorporate the latest clinical and neuroimaging information that has shed new light on TIA pathophysiology. Patients suffering from TIA are at a substantial risk of subsequent stroke, but quantifying this risk is difficult as TIA patients are a heterogeneous population and there are multiple TIA mimics. Clinical scores for prediction of stroke risk are principally based on patient history and potentially understate actual risk. Magnetic resonance imaging (MRI), in particular diffusion-weighted imaging (DWI) performed in the first days following TIA, reveals relevant focal ischemic abnormalities in 21-68% of patients. These lesions predict stroke recurrence, functional dependence and subsequent vascular events. Adding imaging information to clinical scores improves prediction of stroke risk following TIA. Alongside clinical judgement, use of MRI has the potential to change the management of TIA patients and is the imaging modality of choice for this condition.