Lin, Michelle J.

Introduction: Cerebral Amyloid Angiopathy (CAA) is caused by the progressive deposition of β-amyloid in the walls of small to medium-sized cerebral vessels. Although seizures represent a debilitating manifestation of CAA, little is known about their prevalence or associated factors. We aim to fill this gap by determining the prevalence of seizures in CAA and identify factors associated with an increased risk of seizures. Methods: We identified consecutive patients with CAA, evaluated within the Mayo Clinic health system between January 2010 and December 2023 using the ICD-10 code. Data on demographics and comorbidities were compared between those with and without seizures using the chi-square test for categorical variables and independent samples t-test for continuous variables. Odds ratios (OR) were estimated after adjusting for age, sex, and race in multivariable logistic regression. Results: We included 1,914 patients with CAA with a mean age of 75.4 ± 8.6 years, of whom 52.3% were female and 87.5% were white. Seizures were observed in 347 patients (18.1%). Individuals with seizures were significantly younger (mean age 67.7 ± 9.1 vs. 77.2 ± 7.5 years, p < 0.001). Multivariable modeling identified alcohol abuse (OR 1.92, 95% CI 1.03-3.56, p=0.04), diabetes mellitus (OR 2.14, 95% CI 1.13-4.06, p=0.02), hypertension (OR 1.79, 95% CI 1.33 - 2.41, p= <0.001), liver disease (OR 1.75, 95% CI 1.14-2.69, p=0.01), and ischemic stroke (OR 1.33, 95% CI 1.01-1.74, p=0.04) as independently associated with an increased risk of seizures. Conclusion: We found that seizures affect nearly one in five patients with CAA. Also, comorbidities such as alcohol abuse, diabetes mellitus, hypertension, liver disease, and ischemic stroke were found to be significantly associated with an increased risk of seizures. Longitudinal studies are warranted to confirm these risk factors, some of which may be modifiable.

Introduction: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited cerebral small vessel disease, yet there is currently no biomarker for early detection. This study aims to identify retinal biomarkers of NOTCH3 carriers using optical coherence tomography (OCT) from the UK Biobank. Methods: We conducted a cross-sectional, matched case-control study of individuals with or without CADASIL from the UK Biobank between 2006 and 2010. All participants had retinal OCT scan and cognitive assessment. Cases were identified based on pathogenic NOTCH3 mutations and 1:1 matched with healthy controls based on age, sex, hypertension, diabetes mellitus, and smoking status. Baseline characteristics and cognitive test scores were compared using chi-square or Mann-Whitney-U test appropriately. Macular thickness (central, inner, and outer subfields) (Figure) and retinal nerve fiber layer (RNFL) thickness were compared using Wilcoxon signed-rank test. Results: Our analysis included 134 participants (67 CADASIL cases, 67 controls) with a mean age of 54±8 years. There were no differences in visual acuity between the two groups. CADASIL performed worse in prospective memory (0.043), verbal and numerical reasoning (p=0.178), visual memory (p=0.227), and processing speed (p=0.101) than matched controls. Participants with CADASIL had significantly thinner macular inner subfield at the superior (p=0.006), temporal (p=0.008), and nasal (p=0.034) quadrants, and significantly thinner RNFL (p=0.008) compared to controls (Table). Conclusion: Individuals with CADASIL have reduced thickness in the inner macular subfield and RFNL relative to matched controls. These retinal group differences were not associated with differences in visual acuity and may reflect early pericyte dysfunction and microvascular ischemia. Longitudinal studies are needed to assess the temporal relationship between these retinal changes and disease progression.

Background: Intracranial atherosclerosis (ICAS) is a common stroke cause, with a recurrent stroke risk of up to 18% per year despite treatment advances. Although lipid-lowering therapies reduce cardiovascular events, their effect on stroke risk in ICAS remains unclear. Objective: To perform a systematic review and meta-analysis assessing the efficacy of lipid-lowering therapies in improving stroke outcomes among patients with ICAS. Methods: A systematic search of PubMed, Embase, Web of Science, Cochrane, and other databases was conducted from inception to November 2023. Eligible studies compared lipid-lowering therapies (Statins and PCSK9i) to standard care or placebo in patients with ICAS. The primary outcome was the incidence of stroke. Pooled relative risks (RR) with 95% confidence intervals (CI) were calculated using a random-effects model, and forest plots were constructed. Chi-square and I 2 statistics were used to assess heterogeneity. Results: Seven observational studies and two randomized controlled trials involving 1,902 ICAS patients were included. Of these, 801 received lipid-lowering therapy, and 1,101 received standard care or placebo. The weighted mean follow-up was 17.6 months (IQR 9.75-25.5). The weighted mean age was 63.7 years (range 55-68) for the lipid-lowering group and 64.0 years (range 50-66) for controls. Females comprised 42% of both groups. Hypertension was present in 74% of the intervention group and 71% of controls. A history of stroke was reported in 32% of the intervention group and 29% of controls. The weighted mean baseline LDL level was 105 mg/dL in the intervention group and 107 mg/dL in controls. The weighted mean change in LDL pre- and post-treatment in the intervention group was -47.18 mg/dL, compared to -12.39 mg/dL in controls. The incidence of ischemic stroke was 5.0% (40/801) in the lipid-lowering group versus 13.0% (143/1,101) in controls (RR 0.40; 95% CI 0.24-0.64; P<0.001, Figure 1a). Subgroup analysis of studies comparing statin versus no statin treatment showed an RR of 0.40 (95% CI 0.30-0.92; P<0.05, Figure 1b). Another subgroup analysis comparing PCSK9 inhibitors and statins versus statins only found an RR of 0.44; 95% CI 0.20-0.96; P<0.05, Figure 1c). Conclusions: Lipid-lowering therapies significantly reduce the risk of ischemic stroke in patients with intracranial atherosclerosis. The addition of PCSK9 inhibitors to statins appears to provide added stroke risk reduction.

Background: Carotid stenosis has been associated with stroke and cognitive impairment. It remains unclear if hypometablism, a marker for neurodegeneration, may be in the mechanistic pathway in the association between carotid stenosis and cognitive decline. This study aims to investigate whether patients with carotid stenosis exhibit reduced cerebral glucose metabolism, using 18-FDG PET imaging as a sensitive measure of brain’s glucose metabolism. Methods: We have identified 138 patients from one health care system who underwent 18-FDG PET imaging and had extracranial carotid imaging (doppler ultrasound/CT angiography/MR angiography) within 1 year of PET scan. Severity of carotid stenosis was defined using NASCET criteria as <50% (mild), 50-69% (moderate), >70% (high-grade). Cerebral glucose metabolism was quantified by measuring standardized uptake value ratio (SUVR) after normalizing to pons in 12 different regions of interest (ROI). Hypometabolism was defined using the cutoff of SUVR <1.41. SUVR and hypometabolism measures were compared across severity of carotid stenosis. Results: Of 138 patients identified, 54 were excluded due to indeterminant ipsilateral hemisphere status. Mild, moderate and severe stenosis was present in 86.9%, 4.8%, 8.3%, respectively. The analysis revealed a numerically reduced cerebral glucose metabolism in patients with moderate to severe carotid stenosis compared to control subjects (Table 1). The most pronounced decrease in FDG uptake was observed in regions supplied by the affected carotid artery, particularly the ipsilateral cortical areas. There was a numerically increased risk of hypometabolism with increasing carotid stenosis: Adjusted odds of hypometabolism ipsilateral to the carotid stenosis were 2.90, 5.56 across patients with moderate and high-grade carotid stenosis in sensorimotor cortex (trend-P=0.095). These findings were consistent across different regions supplied by the stenotic carotid artery but attenuated in territories supplied by unaffected posterior arteries (Table 2). Conclusions: FDG-PET imaging demonstrates reduced glucose metabolism in patients with carotid stenosis, suggesting that cerebral hypoperfusion may contribute to the metabolic disturbances observed in these patients. These results underscore the importance of early detection and management of carotid stenosis to mitigate potential cerebral metabolic deficits and the associated risk of dementia and ischemic stroke.