Optimal Timing for Resumption of Anticoagulation After Intracranial Hemorrhage in Patients With Mechanical Heart Valves

BACKGROUND

Anticoagulation in patients with intracranial hemorrhage (ICH) and mechanical heart valves is often held for risk of ICH expansion; however, there exists a competing risk of acute ischemic stroke (AIS). Optimal timing to resume anticoagulation remains uncertain.

METHODS AND RESULTS

We retrospectively studied patients with ICH and mechanical heart valves from 2000 to 2018. The primary outcome was a composite end point of symptomatic hematoma expansion or new ICH, AIS, and intracardiac thrombus up to 30 days post-ICH. The exposure was timing of reinitiation of anticoagulation classified as early (resumed up to 7 days after ICH), late (≥7 and up to 30 days after ICH), and never if not resumed or resumed after 30 days post-ICH. We included 184 patients with ICH and mechanical heart valves (65 anticoagulated early, 100 late, 19 not resumed by day 30 post-ICH). Twelve patients had AIS, 16 new ICH, and 6 intracardiac thromboses. The mean time from ICH to anticoagulation was 12.7 days. Composite outcomes occurred in 12 patients resumed early (18.5%), 14 resumed late (14.0%), and 4 never resumed (21.1%). There was no increased hazard of the composite outcome (hazard ratio [HR], 1.1 [95% CI, 0.2-6.0]), AIS, or worsening or new ICH among patients resumed early versus late. There was no difference in the composite among patients never resumed versus resumed. Patients who never resumed anticoagulation had significantly more severe ICH (median Glasgow Coma Scale: 10.6, 13.9, and 13.9 among those who resumed never, early, and late, respectively; P=0.0001), higher in-hospital mortality (56.5%, 0%, and 0%, respectively; P<0.0001), and an elevated 30-day AIS risk (HR, 15.9 [95% CI, 1.9-129.7], P=0.0098).

CONCLUSIONS

In this study of patients with ICH and mechanical heart valves, there was no difference in 30-day thrombotic and hemorrhagic brain-related outcomes when anticoagulation was resumed within 7 versus 7 to 30 days after ICH. Withholding anticoagulation >30 days was associated with severe baseline ICH, higher in-hospital case fatality, and elevated AIS risk.

Peak Width of Skeletonized Mean Diffusivity as Neuroimaging Biomarker in Cerebral Amyloid Angiopathy

BACKGROUND AND PURPOSE

Whole-brain network connectivity has been shown to be a useful biomarker of cerebral amyloid angiopathy and related cognitive impairment. We evaluated an automated DTI-based method, peak width of skeletonized mean diffusivity, in cerebral amyloid angiopathy, together with its association with conventional MRI markers and cognitive functions.

MATERIALS AND METHODS

We included 24 subjects (mean age, 74.7 [SD, 6.0] years) with probable cerebral amyloid angiopathy and mild cognitive impairment and 62 patients with MCI not attributable to cerebral amyloid angiopathy (non-cerebral amyloid angiopathy-mild cognitive impairment). We compared peak width of skeletonized mean diffusivity between subjects with cerebral amyloid angiopathy-mild cognitive impairment and non-cerebral amyloid angiopathy-mild cognitive impairment and explored its associations with cognitive functions and conventional markers of cerebral small-vessel disease, using linear regression models.

RESULTS

Subjects with Cerebral amyloid angiopathy-mild cognitive impairment showed increased peak width of skeletonized mean diffusivity in comparison to those with non-cerebral amyloid angiopathy-mild cognitive impairment (P < .001). Peak width of skeletonized mean diffusivity values were correlated with the volume of white matter hyperintensities in both groups. Higher peak width of skeletonized mean diffusivity was associated with worse performance in processing speed among patients with cerebral amyloid angiopathy, after adjusting for other MRI markers of cerebral small vessel disease. The peak width of skeletonized mean diffusivity did not correlate with cognitive functions among those with non-cerebral amyloid angiopathy-mild cognitive impairment.

CONCLUSIONS

Peak width of skeletonized mean diffusivity is altered in cerebral amyloid angiopathy and is associated with performance in processing speed. This DTI-based method may reflect the degree of white matter structural disruption in cerebral amyloid angiopathy and could be a useful biomarker for cognition in this population.

Abstract 9: Peak Width of Skeletonized Mean Diffusivity and Cognition in Cerebral Amyloid Angiopathy

Background: We hypothesized that Peak Width of Skeletonized Mean Diffusivity (PSMD), an automated marker of cerebral microangiopathy representing microstructural disruption of white matter (WM), would be increased in patients with cerebral amyloid angiopathy (CAA) compared to healthy controls (HCs) and increased PSMD would be associated with lower processing speed scores (PSSs) in patients with CAA.

Methods: Seventy-two nondemented probable CAA patients and 23 HCs prospectively underwent high-resolution brain MRIs and cognitive tests. PSMD scores were quantified from a probabilistic skeleton of the WM tracts as previously validated (http://www.psmd-marker.com). In subjects with intracerebral hemorrhage (ICH, n=27), ICH regions were masked and removed from the PSMD pipeline. The analyses were repeated in the non-ICH hemisphere. Raw scores of Trail Making Test-B and Symbol Substitution Test were transformed into standardized z -scores and averaged to obtain PSSs.

Results: The mean age (p=0.366) and sex (p=0.811) were similar between CAA patients and HCs. PSMD was higher in the CAA group [(3.95±0.9) х 10 –4 mm 2 /s] compared to HCs [(3.32±0.6) х 10 –4 mm 2 /s] (p=0.003). This association remained significant in a linear regression model corrected for age and sex (β=0.700, 95%CI 0.3-1, p=0.001). Within the CAA cohort, higher PSMD was associated with higher WM hyperintensity volume in a multiple regression model adjusted for all relevant variables (β=0.890, 95%CI 0.7-1, p<0.001). In a regression model corrected for age, sex, years of education and presence of ICH, a lower PSS was independently associated with increased PSMD (β=-0.405, 95%CI {-0.6}-{-0.2}, p<0.001). These results did not change when the non-ICH hemisphere was used for PSMD processing.

Conclusion: PSMD is increased in CAA and is associated with worse PSSs supporting the view that disruption of white matter has a significant role in cognitive impairment in CAA.

Abstract P409: Cerebellar Atrophy and Its Clinical Implications in Cerebral Amyloid Angiopathy

Background: Recent data show that cerebral amyloid angiopathy (CAA) might cause hemorrhagic lesions in cerebellar cortex as well as cerebral atrophy. However, the potential effect of CAA on cerebellar tissue loss and its clinical implications have not been investigated.

Methods: We compared cerebellar volumes in 70 nondemented patients with probable CAA to 70 age-matched healthy controls (HC) and 70 age-matched Alzheimer’s disease (AD) patients. Volumetric analyses including cerebellar cortical volume (pCbll-CV), cerebellar subcortical volume (pCbll-ScV), cerebral white matter volume (pWMV), and cerebral white matter hyperintensity volume (pWMH) were calculated as percent of total intracranial volume. Gait velocity (meters/seconds) was used to investigate the potential effect of cerebellar tissue loss on gait function.

Results: Patients with CAA had significantly lower pCbll-ScV and pCbll-CV compared to HC (1.49%±0.17 vs 1.71%±0.23, p<0.001 and 6.03%±0.50 vs 6.23%±0.56, p<0.027 respectively). When compared to AD, pCbll-ScV but not pCbll-CV was significantly lower in CAA (1.49%±0.17 vs 1.670.24, p<0.001). Diagnosis of CAA was independently associated with lower pCbll-ScV in a general linear model adjusting for age, sex and presence of hypertension when compared to both HCs and patients with AD (p<0.0001 for all associations, after Bonferroni correction for multiple comparisons). Lower pCbll-ScV was associated with lower gait velocity score in univariate and multivariate analysis adjusted for relevant variables (adjusted β=0.826, 95%CI 0.357-1.295, p=0.001).

Conclusion: Patients with CAA show cerebellar atrophy; predominantly in the subcortical cerebellum when compared to both HC and AD patients. Cerebellar tissue loss independently correlated with worse gait function in CAA patients. Overall, this study supports the view that CAA causes cerebellar injury which might mediate gait disturbance in patients with CAA.

Abstract TMP111: Prediction of Cognitive Impairment after Intracerebral Hemorrhage using MRI Small Vessel Disease Score

Introduction: Survivors of Intracerebral Hemorrhage (ICH) are at high risk for cognitive impairment. Previous studies clarified that Cerebral Small Vessel Disease (CSVD) is a primary contributor to post-ICH dementia, but these observations have failed to transform clinical or research practice standards to date. We sought to determine whether a validated MRI CSVD scoring system could readily predict cognitive impairment after ICH.

Methods: We analyzed data from ICH survivors with no history of prior cognitive impairment, enrolled in a single-center prospective study. We reviewed MRI scans to compute: 1) a validated 6-point score for CSVD burden based on presence of microbleeds, white matter hyperintensities, lacunes and >20 basal ganglia enlarged perivascular spaces; 2) cortical atrophy. We quantified cognitive performance by: 1) administering the Telephone Interview for Cognitive Status (TICS) test; 2) identifying diagnosis of dementia based on medical records. We utilized linear mixed model analyses to identify predictors of changes in TICS score, and Cox regression to identify predictors of new-onset dementia. We calculated CSVD score cut-offs to maximize sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for diagnosis of dementia.

Results: We enrolled 612 primary ICH survivors, and followed them for a median of 46.3 months (Inter-Quartile Range: 35.5-58.7). A total of 214/612 (35%) participants developed dementia. Increasing CSVD scores were associated with faster cognitive decline (Coeff -0.25, Standard Error 0.02) and dementia diagnosis (Hazard Ratio 1.33, 95% CI 1.08-1.64). Age, increasing atrophy scale score, lower TICS score at baseline and systolic blood pressure were also independently associated with faster cognitive decline and new-onset dementia (all p<0.001). A CSVD score cut-off of ≥ 2 had highest sensitivity (83%) and specificity (91%) for dementia diagnosis, with PPV of 84% and NPV of 91% respectively.

Conclusion: This validated CSVD score is strongly associated with cognitive performance after ICH, with excellent predictive performance for future diagnosis of dementia. Our results support its implementation in clinical care and in future studies of post-ICH dementia.

Abstract WP371: Cortical Superficial Siderosis and Mortality in Cerebral Amyloid Angiopathy

Objective: To investigate whether magnetic resonance imaging (MRI) markers of cerebral small vessel disease predict overall mortality in cerebral amyloid angiopathy (CAA) patients.

Methods: Subjects were consecutive survivors (age≥55) of spontaneous symptomatic CAA-related-lobar ICH and CAA presenting without lobar ICH, diagnosed according to the Boston criteria drawn from an ongoing longitudinal cohort study and Memory Disorder Unit. All subjects had brain MRI at presentation. Baseline clinical, imaging, laboratory data and mortality information were collected. Neuroimaging markers including focal (≤3 sulci) or disseminated (>3 sulci) cortical superficial siderosis (cSS), cortical subarachnoid hemorrhage (cSAH), cerebral microbleeds (CMBs), enlarged perivascular spaces (EPVS) and white matter hyperintensities (WMH) were evaluated. Overall mortality risk was assessed using Cox proportional hazards models adjusting for potential confounders.

Results: A total of 335 patients with probable CAA were enrolled, 196 presenting with lobar ICH and 139 without lobar ICH. During a median follow-up time of 3.44 years (interquartile range 1.61- 5.52 years), 181 of 335 patients (54.0%) died, 37.3% were patients with lobar ICH and 16.7% were those without. In univariable analysis, disseminated cSS, moderate to severe WMH, higher age and CAA related-lobar ICH group were predictors of overall mortality (p<0.05 for all comparisons). After adjusting for moderate to severe WMH and multiple CMBs (CMBs ≥5 foci), disseminated cSS remained as an independent neuroimaging predictor of overall mortality (HR 1.66; 95% CI 1.05-2.64, p = 0.030). Other predictors of mortality were older age (HR 1.08; 95% CI 1.06-1.11, p < 0.001) and presence of lobar ICH (HR 1.87; 95% CI 1.34-2.61, p < 0.001). The mortality risk was even greater in patients with both disseminated cSS and lobar ICH (HR 2.28; 95% CI 1.41-3.69, p = 0.001) and as well as in older patients (age>75 years) with disseminated cSS (HR 1.86; 95% CI 1.08-3.23, p = 0.026).

Conclusion: Disseminated cSS is an independent neuroimaging biomarker of increased risk of overall mortality in probable CAA, particular in those patients with lobar ICH and older age. These findings may serve identify important markers of CAA severity.

Abstract 212: Cortical Superficial Siderosis and Risk of Recurrent Intracerebral Haemorrhage in Cerebral Amyloid Angiopathy: A Meta-analysis

Background: Cerebral amyloid angiopathy (CAA) is a major cause of spontaneous lobar intracerebral hemorrhage (ICH) in the elderly. CAA-related ICH survivors are at substantial risk for recurrent ICH, accounting for the significant morbidity of the disease. Identifying predictors of recurrence is therefore crucial. Recent data have implicated cortical superficial siderosis (cSS) as a key hemorrhagic MRI signature of CAA, and a possible marker of increased risk for CAA-ICH recurrence. However, data remain limited. We obtained precise estimates on cSS as an independent predictor of ICH recurrence risk in CAA cohorts from a systematic review of published studies pooled with data from our centre.

Methods: We included cohort studies of consecutive CAA-related ICH patients based on the original Boston criteria, with available blood-sensitive MRI sequences at baseline for cSS assessment, and adequate follow-up for recurrent symptomatic ICH. The strength of the association between cSS and recurrent ICH was quantified using random effects models. Covariate-adjusted hazard rations (adj-HR) as provided from pre-specified Cox proportional hazard models were used for a two-stage meta-analysis.

Results: Three cohorts including 443 CAA-ICH patients were eligible for analysis. The pooled prevalence of cSS presence and disseminated cSS (>3 affected sulci) was 32% (95%CI: 32%-41%) and 21% (95%CI: 18%-25%) respectively. During a mean follow-up of 2.5 years (range: 2-3 years) 92 patients experienced recurrent ICH, a pooled risk ratio of 6.9% per year (I 2 : 63%, p=0.07). In adjusted pooled analysis, any cSS and disseminated cSS were both independently associated with increased lobar ICH recurrence risk (adj-HR: 2.4; 95%CI: 1.5-3.8; p<0.0001, I 2 : 0% and adj-HR: 4.1; 95%CI: 2.6-6.6; p<0.0001, I 2 : 47%), after adjusting for multiple strictly lobar microbleeds presence and increasing age.

Conclusions: Our findings in a large population of CAA patients with ICH and a large number of recurrence events, indicate that cSS, particularly if disseminated, is the single most important prognostic risk factor on MRI for future recurrent lobar ICH. The provided estimates may help stratify future bleeding risk in CAA, with clinical implications for prognosis and treatment.

Effect of CTA Tube Current on Spot Sign Detection and Accuracy for Prediction of Intracerebral Hemorrhage Expansion

BACKGROUND AND PURPOSE

Reduction of CT tube current is an effective strategy to minimize radiation load. However, tube current is also a major determinant of image quality. We investigated the impact of CTA tube current on spot sign detection and diagnostic performance for intracerebral hemorrhage expansion.

MATERIALS AND METHODS

We retrospectively analyzed a prospectively collected cohort of consecutive patients with primary intracerebral hemorrhage from January 2001 to April 2015 who underwent CTA. The study population was divided into 2 groups according to the median CTA tube current level: low current (<350 mA) and high current (≥350 mA). CTA first-pass readings for spot sign presence were independently analyzed by 2 readers. Baseline and follow-up hematoma volumes were assessed by semiautomated computer-assisted volumetric analysis. Sensitivity, specificity, positive and negative predictive values, and accuracy of spot sign in predicting hematoma expansion were calculated.

RESULTS

This study included 709 patients (288 and 421 in the low- and high-current groups, respectively). A higher proportion of low-current scans identified at least 1 spot sign (20.8% versus 14.7%, P = .034), but hematoma expansion frequency was similar in the 2 groups (18.4% versus 16.2%, P = .434). Sensitivity and positive and negative predictive values were not significantly different between the 2 groups. Conversely, high-current scans showed superior specificity (91% versus 84%, P = .015) and overall accuracy (84% versus 77%, P = .038).

CONCLUSIONS

CTA obtained at high levels of tube current showed better diagnostic accuracy for prediction of hematoma expansion by using spot sign. These findings may have implications for future studies using the CTA spot sign to predict hematoma expansion for clinical trials.

Abstract 122: Cortical Superficial Siderosis is a Predictor of Early Recurrent Intracerebral Hemorrhage in Cerebral Amyloid Angiopathy

Background and Purpose: Cerebral amyloid angiopathy (CAA) is a major cause of lobar intracerebral hemorrhage (ICH). A subgroup of patients with CAA experience multiple, recurrent ICHs over a short period of time. In this study, we investigated predictors of early lobar ICH recurrence (defined as ICH within six month after index event) in order to better understand the mechanisms for early recurrence in CAA-related ICH.

Methods: Subjects were consecutive survivors (age≥55) of spontaneous symptomatic CAA-related lobar ICH according to the Boston criteria drawn from an ongoing longitudinal cohort study. All subjects had brain computed tomography (CT) scan and magnetic resonance imaging (MRI) at presentation. Baseline clinical, imaging and laboratory data were collected. Neuroimaging markers including focal (≤3 sulci) or disseminated (>3 sulci) cortical superficial siderosis (cSS), acute convexity subarachanoid hemorrhage (cSAH), cerebral microbleeds (CMBs), white matter hyperintensities and baseline ICH volume, on CT and/or MRI were evaluated. Subjects were followed prospectively for future recurrent symptomatic ICH. Cox proportional hazard models were used to identify predictors of early recurrent ICH adjusting for potential confounders.

Results: A total of 296 patients with probable or possible CAA were enrolled. In univariable analysis, the presence of disseminated cSS, cSAH, and number of CMBs were predictors of early recurrent ICH (p<0.05 for all comparisons). After adjusting for age and previous symptomatic ICH history, disseminated cSS on MRI and cSAH on CT were independent predictors of early recurrent ICH (HR 3.79, 95% CI 1.46-9.84, p=0.006, HR 3.16, 95% CI 1.05-9.51, p=0.041, respectively).

Conclusions: Disseminated cSS on MRI and cSAH on CT are independent imaging markers of increased risk for early recurrent ICH. These markers may provide additional insights into the mechanisms of ICH recurrence in patients with CAA.

Abstract WP415: What Factors Determine Choice of Anticoagulant?

Introduction: Non-vitamin K antagonist Oral Anticoagulation (NOAC) agents are approved for prevention of ischemic stroke in atrial fibrillation (Afib). NOACs offer both advantages (ease of use, reduced rate of intracranial hemorrhage) and disadvantages (cost, absence of reversal agent, less clinical experience) relative to warfarin. We tested the hypothesis that the decision to prescribe a NOAC might be influenced by non-medical factors such as prescriber subspecialty or patient demographics.

Methods: We performed an IRB-approved search of the Research Patient Data Registry at our major tertiary referral hospital for all Afib patients prescribed warfarin, dabigatran, rivaroxaban or apixaban between January 2013 and June 2014. We encoded data related to prescriber clinic, patient demographics (including home ZIP code as a marker of family income), intracerebral hemorrhage (ICH) and medical comorbidities.

Results: Of 4,261 individuals with Afib prescribed oral anticoagulants during the specified interval, 3450 (81%) received warfarin, 442 (10.4%) rivaroxaban, 304 (7.1%) dabigatran, and 65 (1.5%) apixaban per their last prescription during the period. In univariate analyses patients prescribed NOACs were younger (71.5 ± 11.4 vs. 76.6 ± 10.5 years, p < 0.001), more likely male (64.4% vs. 35.6%, p < 0.005), had lower CHADS2 scores (2.17 ± 1.43 vs. 2.68 ± 1.40, p<0.001) and resided in areas with higher median income ($86,384 ± 33,410 vs. $80,470 ± 30,390, p<0.001). Race and prior ICH did not differ. Among 2,013 prescriptions from a defined subset of cardiology, primary care and neurology clinics, NOACs were more commonly used by cardiologists (37.1%) than neurologists (18.9%) or primary care providers (17.1%, p<0.001). Multivariable analysis of this subset found that physician specialty, residential area income, age and CHADS2 score but not gender were independently associated with receiving a NOAC.

Conclusions: Younger, more affluent individuals treated by a cardiologist were likeliest to receive NOACs for prevention of Afib-related stroke. The data suggest that factors other than medical characteristics might influence the decision to use NOACs.

Abstract 124: Progression of Brain Network Alterations in Patients With Cerebral Amyloid Angiopathy

Introduction: Cerebral amyloid angiopathy (CAA) is a common form of small vessel disease. We recently showed that CAA is associated with functionally relevant brain network alterations, in particular affecting white matter connections in posterior regions. Here we examined how these brain network alterations progress over time.

Hypothesis: Brain white matter network alterations in CAA progress from posterior to frontal regions.

Methods: Thirty-three patients with probable CAA (16 with intracerebral hemorrhage (ICH)) underwent multimodal brain MRI at two time points (mean follow-up time: 1.3±0.4 years). Brain networks were reconstructed using graph theory and the global efficiency and mean fractional anisotropies (FA) of posterior-posterior, frontal-frontal, and posterior-frontal connections of the ICH-free hemisphere were calculated. Microbleed count, dichotomized at the median, was used as a marker of CAA severity. We evaluated changes in FA and global efficiency over time in patients with moderate (n<35) vs. high (n≥35) microbleed counts with repeated measures analysis adjusted for age.

Results: For all CAA patients, the FA of posterior-posterior connections declined between baseline and follow-up (effect of time: p=0.02; time x group interaction: p=0.16). A decline in FA of posterior-frontal and frontal-frontal connections was observed for patients with high but not moderate microbleed counts (time x group interaction: p=0.007 and p=0.005). A similar time x group interaction effect was observed for global network efficiency (p=0.03). Associations were independent of ICH, white matter hyperintensity volume, or total brain volume.

Conclusions: Brain network alterations in patients with CAA worsen measurably over just 1.3-year follow-up and appear to progress from posterior to frontal regions with increasing disease severity.

Decoupling of structural and functional brain connectivity in older adults with white matter hyperintensities

Age-related impairments in the default network (DN) have been related to disruptions in connecting white matter tracts. We hypothesized that the local correlation between DN structural and functional connectivity is negatively affected in the presence of global white matter injury. In 125 clinically normal older adults, we tested whether the relationship between structural connectivity (via diffusion imaging tractography) and functional connectivity (via resting-state functional MRI) of the posterior cingulate cortex (PCC) and medial prefrontal frontal cortex (MPFC) of the DN was altered in the presence of white matter hyperintensities (WMH). A significant correlation was observed between microstructural properties of the cingulum bundle and MPFC-PCC functional connectivity in individuals with low WMH load, but not with high WMH load. No correlation was observed between PCC-MPFC functional connectivity and microstructure of the inferior longitudinal fasciculus, a tract not passing through the PCC or MPFC. Decoupling of connectivity, measured as the absolute difference between structural and functional connectivity, in the high WMH group was related to poorer executive functioning and memory performance. These results suggest that such decoupling may reflect reorganization of functional networks in response to global white matter pathology and may provide an early marker of clinically relevant network alterations.

Progression of white matter lesions and hemorrhages in cerebral amyloid angiopathy

OBJECTIVE

To determine the rate of progression of white matter lesions and hemorrhages in a cohort with cerebral amyloid angiopathy (CAA).

METHODS

The authors analyzed data from 26 patients with possible (3) or probable (23) CAA, diagnosed by the Boston Criteria. Brain maps of white matter hyperintensities, normalized to head size (nWMH), were created by blinded computer-assisted segmentation of MRI images obtained at baseline and after a median follow-up interval of 1.1 year.

RESULTS

There was a substantial nWMH volume increase over the interscan interval (median 0.5 mL/year, interquartile range 0.1 to 2.8, p < 0.001). The median yearly increase, expressed as a percentage of the baseline WMH volume, was 18%. The characteristic most strongly associated with nWMH volume increase was the baseline nWMH volume (r = 0.57, p = 0.002). The volume of nWMH progression was also associated with history of cognitive impairment (median 5.0 mL/year in cognitively impaired subjects vs 0.3 mL/year in cognitively unimpaired, p = 0.02) but not age or hypertension. This association remained present in an analysis stratified by baseline WMH volume. New hemorrhages, including asymptomatic microbleeds, were seen in 46% of subjects. The number of new MRI hemorrhages correlated strongly with baseline nWMH (r = 0.53, p = 0.005) but not with nWMH progression (r = 0.22, p = 0.28).

CONCLUSIONS

There is a progressive increase in white matter lesions in subjects with cerebral amyloid angiopathy. The association of white matter lesions with incident lobar hemorrhages suggests that white matter damage may reflect a progressive microangiopathy due to cerebral amyloid angiopathy.

Plasma beta-amyloid and white matter lesions in AD, MCI, and cerebral amyloid angiopathy

BACKGROUND

Microvascular brain injury, typically measured by extent of white matter hyperintensity (WMH) on MRI, is an important contributor to cognitive impairment in the elderly. Recent studies suggest a role for circulating beta-amyloid peptide in microvascular dysfunction and white matter disease.

METHODS

The authors performed a cross-sectional study of clinical, biochemical, and genetic factors associated with WMH in 54 subjects with Alzheimer disease (AD) or mild cognitive impairment (AD/MCI) and an independent group of 42 subjects with cerebral amyloid angiopathy (CAA). Extent of WMH was determined by computer-assisted volumetric measurement normalized to intracranial size (nWMH). Biochemical measurements included plasma concentrations of the 40- and 42-amino acid species of beta-amyloid (Abeta40 and Abeta42) detected by specific enzyme-linked immunosorbent assays.

RESULTS

Plasma Abeta40 concentrations were associated with nWMH in both groups (correlation coefficient = 0.48 in AD/MCI, 0.42 in CAA, p < or = 0.005). Plasma Abeta40 remained independently associated with nWMH after adjustment for potential confounders among age, hypertension, diabetes, homocysteine, creatinine, folate, vitamin B12, and APOE genotype. The presence of lacunar infarctions was also associated with increased Abeta40 in both groups. nWMH was greater in CAA (19.8 cm3) than AD (11.1 cm3) or MCI (10.0 cm3; p < 0.05 for both comparisons).

CONCLUSIONS

Plasma beta-amyloid 40 concentration is independently associated with extent of white matter hyperintensity in subjects with Alzheimer disease, mild cognitive impairment, or cerebral amyloid angiopathy. If confirmed in longitudinal studies, these data would suggest circulating beta-amyloid peptide as a novel biomarker or risk factor for microvascular damage in these common diseases of the elderly.

Association of homocysteine with plasma amyloid β protein in aging and neurodegenerative disease

BACKGROUND

Elevated plasma total homocysteine (tHcy) is a risk factor for cardiovascular disease and is reported to be an independent risk factor for Alzheimer disease (AD) and cognitive decline. tHcy may potentiate neurotoxic and vasculopathic processes, including amyloid beta protein (Abeta) metabolism, implicated in neurodegenerative diseases.

OBJECTIVE

To examine the relationship of plasma total tHcy levels with clinical, demographic, biochemical, and genetic factors in aging, mild cognitive impairment (MCI), AD, cerebral amyloid angiopathy (CAA), and Parkinson disease (PD).

METHODS

Plasma tHcy, folate, vitamin B(12), creatinine, and Abeta levels were assessed in individuals evaluated in the Memory, Stroke, and Movement Disorders Units of Massachusetts General Hospital with diagnoses of AD (n = 145), MCI (n = 47), PD (n = 93), CAA (67), hypertensive intracerebral hemorrhage (hICH) (n = 25), and no dementia (n = 88).

RESULTS

The tHcy levels did not differ across AD, MCI, CAA, hICH, and nondemented control subjects but were increased in the PD group (p < 0.01). The elevated levels within the PD group were due to high tHcy in individuals taking levodopa (p < 0.0001). Increasing tHcy was associated with worse cognition in the PD cases, but not the other diagnostic groups. tHcy levels positively correlated with plasma Abeta levels even after adjustments for age and creatinine (p < 0.0001).

CONCLUSIONS

Mean tHcy levels increased with age but did not discriminate diagnostic groups aside from significant elevation in patients with PD taking levodopa. The positive association between tHcy and plasma Abeta levels raises the possibility that these circulating factors could interact to affect AD risk and cognition in PD.

White matter lesions, cognition, and recurrent hemorrhage in lobar intracerebral hemorrhage

BACKGROUND

Accumulating evidence suggests that white matter lesions are associated with vascular cognitive impairment. The authors investigated the relationships between white matter lesions, cognitive impairment, and risk of recurrent hemorrhage in a prospectively identified cohort of patients with lobar intracerebral hemorrhage (ICH).

METHODS

The authors collected clinical and genetic information on 182 consecutive patients age > or = 55 who had CT scan at admission for lobar ICH. White matter disease was graded on CT in all subjects and on MRI in a subset of 82 patients. All scans were interpreted blinded to clinical information. Survivors were followed for recurrent ICH by telephone interview.

RESULTS

White matter damage was common (present on CT in 77%) and severe (advanced CT grade in 32%). White matter damage was correlated with the total number of hemorrhages on gradient-echo MRI and with risk of recurrent ICH. Subjects with cognitive impairment prior to their index ICH were more likely to have severe white matter damage on CT (OR 3.6, 95% CI 1.6 to 8.1, p = 0.003) and more likely to have advanced periventricular hyperintensities on MRI. The relationships between white matter damage and cognitive impairment were similar in the subset of 88 subjects meeting criteria for probable or definite cerebral amyloid angiopathy and remained independent after adjustment for age, cortical atrophy, and APOE genotype.

CONCLUSIONS

White matter damage in lobar ICH is common and is associated with cognitive impairment. These data support the possibility that an underlying vasculopathy in lobar ICH patients, possibly cerebral amyloid angiopathy, can cause clinically important vascular dysfunction.

Stroke unit versus neurology ward

INTRODUCTION

Few studies have tested the hypothesis of whether the beneficial effect of Stroke Units (SUs) can be reproduced in routine clinical practice and whether SU are also superior to neurological wards [NWs]. We aimed to compare the outcomes of patients of a newly implemented SU to the outcomes of patients hospitalized in a NW.

METHODS

We made a before-after comparison of 352 SUs and 352 NWs patients after adjusting for case-mixes by the multivariate method. Subgroup analyses were also performed to evaluate which patient groups benefit the most. In-hospital case-fatality, proportion of independent patients at discharge, length of hospital stay (LOHS), medical complication rate were the main outcome measures.

RESULTS

Adjusted in-hospital case fatality was significantly reduced in the SUs (OR: 0.44, 95 % CI: 0.26-0.76; p = 0.003). The proportion of independent patients at discharge and patients having medical complications was not different. Length of hospital stay was shorter in SU patients (13.76 days vs. 16.72 days, p = 0.003). Treatment in the SUs decreased case fatality in many subgroups [men, elderly, early admitted, severe stroke, co-morbidity present and ischemic stroke groups].

DISCUSSION

The results of randomized trials in favor of SUs can be reproduced in routine clinical practice. The benefit of SU care seems to be more apparent with advancing age and increasing stroke severity. Stroke Unit seems to be a better alternative to an experienced NW.

Venous infarction of brainstem and cerebellum

The authors describe 2 cases of posterior fosa venous infarction. A 56-year-old woman with essential thrombocytemia presented with fluctuating complaints of headache, nausea, vomiting, left-sided numbness-weakness, and dizziness and became progressively stuporous. Cranial magnetic resonance imaging (MRI) showed bilateral parasagittal fronto-parietal and left cerebellar contrast-enhancing hemorrhagic lesions. On magnetic resonance venography, the left transverse and sigmoid sinuses were occluded. The second patient, a 39-year-old woman, presented with acute onset of diplopia, numbness of the tongue, vertigo, and right-sided weakness following a gestational age stillbirth. MRI revealed lesions in the right half of midbrain and pons and in the superior part of the right cerebellar hemisphere. Digital subtraction angiography showed right transverse and sigmoid sinus occlusion. The authors suggest that one should investigate the possibility of venous infarction in the presence of posterior fossa lesions that are often hemorrhagic and are not within any arterial territory distribution but respect a known venous drainage pattern. Recognition of the observed clinical and neuroimaging features can lead to earlier diagnosis and, potentially, more effective management.