30 research outputs found
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Automated delineation of enlarged perivascular spaces (EPVS)
Background
Enlarged Perivascular Spaces (EPVS) are associated with small vessel disease. The objective of this study was to develop semi‐automated techniques for the quantification of EPVS burden.
Method
An intensity‐based threshold was used to identify EPVS. A threshold of maximum plus two standard deviations of intensities of normal‐appearing white matter in the supratentorial region was used to identify EPVS. To compare the performance of the semi‐automatic approach for EPVS segmentation to visually rated EPVS scores, two regions of interest were outlined in the basal ganglia (BG) region and the centrum semiovale (CS). For both these regions, a score was generated by an experienced neurologist by visually counting the number of EPVS with a score of zero representing the absence of any EPVS, a score of 1 representing 1‐10 EPVS, a score of 2 representing 11‐20 EPVS, a score of 3 representing 21‐40 EPVS, and a score of 4 representing >40 EPVS. The semi‐automatic approach provided a count of the number of EPVS that were converted to grade using the same scaling as the visual approach. Spearman Rank Order Correlation Coefficient was calculated to estimate the correlation between the two methods. Mann‐Whitney U tests of ranks are employed to determine if any group differences are present. Finally, Cohen’s kappa was used to compare the concordance between measures between the two different methods.
Result
Figure 2 shows the results of the segmentation in subjects with differing EPVS burden. Spearman Rank Order Correlation analysis showed a significant correlation between the EPVS scores determined visually and those obtained semi‐automatically in 60 subjects (Table 1). Results of the Mann‐Whitney U tests showed that there was no statistically significant (p > 0.05) difference between the EPVS scores obtained visually and using the semi‐automatic approach (Table 2). Cohen's κ test showed that there was moderate agreement between the two estimation methods in the BG (κ = .522, p < .0001) and CS regions (κ = .571, p < .0001).
Conclusion
The developed method showed good concordance with expert visual read and can provide quantitative measures of EPVS burden (counts and volume) for evaluation of vascular risk
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Structural Basal Ganglia Correlates of Subjective Fatigue in Middle-Aged and Older Adults
Fatigue is among the most common complaints in community-dwelling older adults, yet its etiology is poorly understood. Based on models implicating frontostriatal pathways in fatigue pathogenesis, we hypothesized that smaller basal ganglia volume would be associated with higher levels of subjective fatigue and reduced set-shifting in middle-aged and older adults without dementia or other neurologic conditions.
Forty-eight non-demented middle-aged and older adults (
= 68.1,
= 9.4;
= 27.3,
= 1.9) completed the Fatigue Symptom Inventory, set-shifting measures, and structural MRI as part of a clinical evaluation for subjective cognitive complaints. Associations were examined cross-sectionally.
Linear regression analyses showed that smaller normalized basal ganglia volumes were associated with more severe fatigue (β = -.29,
= .041) and poorer Trail Making Test B-A (TMT B-A) performance (β = .30,
= .033) controlling for depression, sleep quality, vascular risk factors, and global cognitive status. Putamen emerged as a key structure linked with both fatigue (
= -.43,
= .003) and TMT B-A (β = .35,
= .021). The link between total basal ganglia volume and reduced TMT B-A was particularly strong in clinically fatigued patients.
This study is among the first to show that reduced basal ganglia volume is an important neurostructural correlate of subjective fatigue in physically able middle-aged and older adults without neurological conditions. Findings suggest that fatigue and rapid set-shifting deficits may share common neural underpinnings involving the basal ganglia, and provide a framework for studying the neuropathogenesis and treatment of subjective fatigue
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Global Vascular Risk Score and CAIDE Dementia Risk Score Predict Cognitive Function in the Northern Manhattan Study
Modifiable vascular risk factors (VRF) have been implicated in cognitive impairment.
We compared the prediction of cognitive performance between the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) dementia risk score, a validated tool to estimate dementia risk using VRF, and the Northern Manhattan Study (NOMAS) global vascular risk score (GVRS), created to predict vascular events.
The CAIDE and GVRS scores were calculated based on baseline VRF among 1,290 stroke-free participants in the prospective population-based NOMAS MRI cohort (mean age 64±8 years, 60% women; 66% Hispanic, 17% Black, 15% White; 46% completed high school). Domain-specific Z-scores were derived for episodic and semantic memory, executive function, and processing speed, and averaged to calculate global cognition.
The CAIDE score was associated with worse global cognition at initial assessment (Beta per SD = -0.347, p < 0.0001), and with greater decline over time (Beta per SD = -0.033, p = 0.02). These associations were largely due to age and education, and the association with cognitive decline was not significant after adjusting for age, sex, and education. The GVRS was inversely associated with global cognition at initial testing (Beta per SD = -0.247, p < 0.0001) and greater decline over time (Beta per SD = -0.127, p < 0.0001), which persisted after adjusting for sociodemographics. The associations for both scores with initial cognitive performance were driven by executive function and processing speed, and the GVRS was associated with decline in episodic memory and processing speed.
The GVRS was a stronger predictor of cognitive decline than the CAIDE in a multi-ethnic urban cohort. The inclusion of glucose and smoking in the GVRS, which are absent in CAIDE, likely explains the better performance of the GVRS
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Associations Between Vascular Risk Factors and Perivascular Spaces in Adults with Intact Cognition, Mild Cognitive Impairment, and Dementia
Background: Perivascular spaces (PVS) are fluid-filled compartments surrounding small intracerebral vessels that transport fluid and clear waste.
Objective: We examined associations between PVS count, vascular and neurodegenerative risk factors, and cognitive status among the predominantly Hispanic participants of the FL-VIP Study of Alzheimer's Disease Risk.
Methods: Using brain MRI (n = 228), we counted PVS in single axial image through the basal ganglia (BG) and centrum semiovale (CSO). PVS per region were scored as 0 (none), 1 (40). Generalized linear models examined PVS associations with vascular risk factors and a composite vascular comorbidity risk (VASCom) score.
Results: Our sample (mean age 72 +/- 8 years, 61% women, 60% Hispanic, mean education 15 +/- 4 years, 33% APOE4 carriers) was 59% hypertensive, 21% diabetic, 66% hypercholesteremic, and 30% obese. Mean VASCom score was 2.3 +/- 1.6. PVS scores ranged from 0-4 in the BG (mean 1.3 +/- 0.7) and CSO (mean 1.2 +/- 0.9), and 0-7 combined (mean 2.5 +/- 1.4). In multivariable regression models, BG PVS was associated with age (beta = 0.03/year, p < 0.0001), Hispanic ethnicity (beta = 0.29, p =0 .01), education (beta= 0.04/year, p = 0.04), and coronary bypass surgery (beta = 0.93, p = 0.02). CSO PVS only associated with age (beta = 0.03/year, p < 0.01). APOE4 and amyloid-beta were not associated with PVS.
Conclusion: BG PVS may be a marker of subclinical cerebrovascular disease. Further research is needed to validate associations and identify mechanisms linking BG PVS and cerebrovascular disease markers. PVS may be a marker of neurodegeneration despite our negative preliminary findings and more research is warranted. The association between BG PVS and Hispanic ethnicity also requires further investigation
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Determinants of enlarged perivascular spaces (ePVS) on MRI: The Florida Vascular Imaging Phenotypes (FL‐VIP) Study of AD risk
Background
PVS are fluid filled compartments surrounding small intracerebral vessels. They are conduits for fluid transport, exchange, and waste clearance. Their relationship to cardiovascular markers is unknown. We tested whether ePVS counts are affected by vascular risk factors and comorbidities.
Method
We analyzed nondemented subjects’ brains from the FL‐VIP (comprised of 1Florida ADRC participants with available high quality 3T MRI). ePVS were defined as parenchymal hypo/hyperintensities of 40). The side with highest ePVS count was graded. BG and CSO scores were summed to yield a 0‐8 total. Generalized linear models were used to estimate ePVS score associations with demographics, vascular risk factors, and vascular comorbidities (VASCom score).
Result
Of 228 non‐demented participants (mean age 72±8 years; 61% women, 60% Hispanic, mean education 15±4 years, 33% ApoE4 carriers), 59% were hypertensive, 21% diabetic, 66% hypercholesteremic, and 30% obese. Mean VASCom score was 2.3±1.6. ePVS scores ranged from 0‐7 (mean 2.5±1.4), 0‐4 for BG (mean 1.3±0.7) and CSO (mean 1.2 ±0.9). Majority of subjects (73%) had a total ePVS score greater than 1. In unadjusted analysis, BG ePVS were correlated with age (r=0.27, P<0.001), hypertension (r=0.19, p=0.008), MI/CHF/Angina (r=0.14, P=0.03), and coronary bypass (r=0.20, P=0.004). CSO ePVS were correlated with age (r=0.23, P=0.0005), obesity (r=‐0.15, p=0.03), and dyslipidemia (r=‐0.14, P=0.04). In multivariable stepwise regression analyses, BG ePVS were associated with age (β=0.024 per year, p=0.0001), being Hispanic (OR=0.21, P=0.035), coronary bypass (OR=0.70, p=0.025), and hypertension (OR =0.17, p=0.079). CSO PeVS were associated with age (β=0.028 per year, P<0.001) and dyslipidemia (OR=‐0.31, P=0.02).
Conclusion
ePVS were more prevalent with aging, greater vascular risk burden, and Hispanic origin. Hypertension, cardiovascular disease and prior coronary bypass surgery were associated with ePVS in BG, but not in CSO. BG ePVS may be an important marker of small vessel disease linking vascular burden and cognitive impairment
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Association of enlarged perivascular spaces (ePVS) and MRI markers of small vessel disease (SVD) and neurodegeneration in the Florida Vascular Imaging Phenotypes (FL‐VIP) Study of AD Risk
Background
PVS are fluid filled compartments surrounding small intracerebral vessels. They are conduits for fluid transport, exchange, and waste clearance. ePVS are observed in AD, but their relation to SVD markers and neurodegeneration is unknown. We tested whether ePVS are correlated with markers of SVD but not cortical atrophy.
Method
We analyzed subjects’ brains from the FL‐VIP (comprised of all 1Florida ADRC participants with high quality 3T MRI). ePVS were defined as parenchymal hypo/hyperintensities of 40). The side with highest ePVS count was graded. BGBG and CSO scores were summed to yield a 0‐8 ePVS total. Generalized linear models were used to estimate ePVS score associations with White‐Matter Hyperintensity Volume (WMHV), silent brain infarcts (SBIs), cerebral microbleeds (CMBs), and mean total cortical thickness. We adjusted for demographics, vascular risk factors and comorbidities, and ApoE4 status.
Result
Of 228 non‐demented participants (mean age 72±8 years; 61% women, 60% Hispanic, mean education 15±4 years, 33% ApoE4 carriers), 59% were hypertensive, 21% diabetic, 66% hypercholesteremic, and 30% obese. Mean VASCom score was 2.3±1.6. 73% of subjects had a total ePVS score >1. Scores ranged from 0‐7 total (mean 2.5±1.4), 0‐4 for BG (mean 1.3±0.7) and CSO (1.2 ±0.9). In unadjusted analyses, total ePVS correlated with WMHV (r=0.46, p<0001), SBI (r=0.17, p=0.009), and CMB (r=0.16, p=0.016). BG ePVS correlated with WMHV, SBI and CMB. CSO ePVS correlated only with WMHV (r=0.32, p=0.002). In multivariable analyses, ePVS correlated with WMHV (β=4.97, p<0.001), SBI (OR=1.36, p=0.027), and CMB (OR=1.43, p=0.019). BG ePVS remained associated with WMHV, SBI and CMB; and CSO ePVS only with WMHV (β=4.70, p=0.039). Total, BG, and CSO ePVS were not associated with cortical thickness.
Conclusion
BG ePVS are highly related to MRI markers of SVD, but not total cortical thickness, and therefore may be considered hallmark features of small vessel disease. CSO ePVS may not have as a prominent role in SVD
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Magnetic Resonance–Guided Laser Interstitial Thermal Therapy for Mesial Temporal Epilepsy: A Case Series Analysis of Outcomes and Complications at 2-Year Follow-Up
Laser interstitial thermal therapy (LITT) presents an important new minimally invasive tool in the management of drug-resistant mesial temporal epilepsy (MTE). However, because of its relative novelty, not much is known about long-term seizure freedom rates. The objective of this study was to evaluate the postsurgical seizure outcome following LITT after a minimum follow-up period of 2 years.
Medical records of all patients who underwent LITT for MTE from 2013 to 2018 at our comprehensive epilepsy center under a single surgeon were retrospectively reviewed. Data related to demographics, presurgical evaluations, and seizure outcome were compared between seizure-free (SF) and non–seizure-free (NSF) patients.
In all, 26 patients were identified with at least 2 years of follow-up. Mean age was 43.8 years ± 11.6 years, and 46.2% were female. After a mean follow-up time of 42.9 months (range, 24.3–58.8 months), 61.5% (16/26) were free of disabling seizures, and 26.9% (7/26) had only rare disabling seizures. Whereas seizure-freedom rates between patients with and without mesial temporal sclerosis (MTS) were not statistically different (68% vs. 43%, P = 0.23), NSF patients without MTS had a shorter median time to first seizure than did NSF patients with MTS (0.55 month vs. 10 months, log-rank test P = 0.007). Postoperative complications occurred in 2 patients (7.7%), consisting of 1 permanent and 1 transient homonymous hemianopia.
LITT appears to be a safe and effective initial surgical option for treatment-resistant MTE. Among patients who have seizures after treatment, those without MTS appear to have seizures earlier than those with MTS
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Long-term seizure and psychiatric outcomes following laser ablation of mesial temporal structures
Postsurgical seizure outcome following laser interstitial thermal therapy (LiTT) for the management of drug-resistant mesial temporal lobe epilepsy (MTLE) has been limited to 2 years. Furthermore, its impact on presurgical mood and anxiety disorders has not been investigated. The objectives of this study were (1) to identify seizure outcome changes over a period ranging from 18 to 81 months; (2) to investigate the seizure-free rate in the last follow-up year; (3) to identify the variables associated with seizure freedom; and (4) to identify the impact of LiTT on presurgical mood and anxiety disorders.
Medical records of all patients who underwent LiTT for MTLE from 2013 to 2019 at the University of Miami Comprehensive Epilepsy Center were retrospectively reviewed. Demographic, epilepsy-related, cognitive, psychiatric, and LiTT-related data were compared between seizure-free (Engel Class I) and non-seizure-free (Engel Class II + III + IV) patients. Statistical analyses included univariate and multivariate stepwise logistic regression analyses.
Forty-eight patients (mean age = 43 ± 14.2 years, range = 21-78) were followed for a mean period of 50 ± 20.7 months (range = 18-81); 29 (60.4%) achieved an Engel Class I outcome, whereas 11 (22.9%) had one to three seizures/year. Seizure-freedom rate decreased from 77.8% to 50% among patients with 24- and >61-month follow-up periods, respectively. In the last follow-up year, 83% of all patients were seizure-free. Seizure freedom was associated with having mesial temporal sclerosis (MTS), no presurgical focal to bilateral tonic-clonic seizures, and no psychopathology in the last follow-up year. Presurgical mood and/or anxiety disorder were identified in 30 patients (62.5%) and remitted after LiTT in 19 (62%).
LiTT appears to be a safe and effective surgical option for treatment-resistant MTLE, particularly among patients with MTS. Remission of presurgical mood and anxiety disorders can also result from LiTT