Search

Background: Automated brain volumetry has been widely used to assess brain volumetric changes that may indicate clinical states and progression. Among the tools that implement automated brain volumetry, AccuBrain has been validated for its accuracy, reliability and clinical applications for the older version (IV1.2). Here, we aim to investigate the performance of an updated version (IV2.0) of AccuBrain for future use from several aspects., Methods: Public datasets with 3D T1-weighted scans were included for version comparisons, each with Alzheimer's disease (AD) patients and normal control (NC) subjects that were matched in age and gender. For the comparisons of the brain volumetric measures quantified from the same scans, we investigated the difference of hippocampal segmentation accuracy (using Dice similarity coefficient [DSC] as the major measurement). As AccuBrain generates a composite index (AD resemblance atrophy index, AD-RAI) that indicates similarity with AD-like brain atrophy pattern, we also compared the two versions for the diagnostic accuracy of AD versus NC with AD-RAI. Also, we examined the intra-scanner reproducibility of the two versions for the scans acquired with short-intervals using intraclass correlation coefficient., Results: AccuBrain IV2.0 presented significantly higher accuracy of hippocampal segmentation (DSC: 0.91 vs. 0.89, p < 0.001) and diagnostic accuracy of AD (AUC: 0.977 vs. 0.921, p < 0.001) than IV1.2. The results of intra-scanner reproducibility did not favor one version over the other., Conclusions: AccuBrain IV2.0 presented better segmentation accuracy and diagnostic accuracy of AD, and similar intra-scanner reproducibility compared with IV1.2. Both versions should be feasible for use due to the small magnitude of differences., (© 2022. The Author(s).)

Oligoclonal IgG bands (OCB) in cerebrospinal fluid (CSF) are important in diagnosis of multiple sclerosis (MS). We evaluated the MRI features of clinically definite MS subjects with and without CSF-OCB. Relapsing MS subjects were recruited from a prospective registry in a university center. CSF-OCB were detected using isoelectric focusing and lgG-specific immunofixation. MRI metrics including brain volumes, lesion volumes and microstructural measures, were analyzed by FMRIB Software Library (FSL) and Statistical Parametric Mapping (SPM). Seventy-five subjects with relapsing MS were analyzed. Forty-four (59%) subjects had an interval MRI at around 1 year. CSF-OCB were detected in 46 (61%) subjects. The OCB-positive group had a higher proportion of cerebellar lesions than the OCB-negative group (23.9% vs. 3.4%, p = 0.057). Except for amygdala volumes which were lower in the OCB-positive group (p = 0.034), other regional brain volumes including the subcortical deep gray matter and corpus callosum were similar. The two groups also showed comparable brain atrophy rate. For DTI, the OCB-positive group showed significantly higher mean diffusivity (MD) value in perilesional normal-appearing white matter (p = 0.043). Relapsing MS patients with and without CSF-OCB shared similar MRI features regarding volumetric analyses and DTI microstructural integrity.

As an enrichment strategy supplemented by the diagnostic framework of subjective cognitive decline (SCD), SCD plus identifies features that may increase the likelihood of including future-Alzheimer's disease (AD) patients. This study aimed to identify the shared and distinct atrophy patterns between patients specified by SCD plus and amnestic mild cognitive impairment (aMCI, a prodromal stage of AD) and to investigate the extent that automated brain magnetic resonance imaging (MRI) volumetry can differentiate patients with SCD from normal control (NC) participants and patients with aMCI. We acquired structural MRI brain scans from 44 patients with aMCI, 40 patients with SCD (who met the major criteria of SCD plus ), and 48 NC participants. Automatic brain segmentation was performed to quantify the volumetric measures of cognitive-relevant areas. These volumetric measures were compared across the 3 groups with analysis of variance. In addition, we performed support vector machine analyses using volumetric measures of single regions or multiple regions to further evaluate the sensitivity of automated brain volumetry in differentiating a specific group from another. The atrophy patterns in patients with aMCI and SCD were similar. Using the regional volumetric measures, we achieved high performance in differentiating aMCI and SCD from NCs (average classification accuracy [ACC] > 90%). However, the performance was not ideal when differentiating aMCI from SCD (ACC < 63%). In conclusion, patients with SCD specified by SCD plus presented similar atrophy patterns as patients with aMCI, which was distinguishable from NC participants. Future studies should aim to associate the atrophy patterns of SCD with possible conversion to aMCI or AD in a longitudinal design.

Brain imaging is essential for the diagnosis and characterization of cerebral small vessel disease. Several magnetic resonance imaging markers have therefore emerged, providing new information on the diagnosis, progression, and mechanisms of small vessel disease. Yet, the reproducibility of these small vessel disease markers has received little attention despite being widely used in cross-sectional and longitudinal studies. This review focuses on the main small vessel disease-related markers on magnetic resonance imaging including: white matter hyperintensities, lacunes, dilated perivascular spaces, microbleeds, and brain volume. The aim is to summarize, for each marker, what is currently known about: (1) its reproducibility in studies with a scan-rescan procedure either in single or multicenter settings; (2) the acquisition-related sources of variability; and, (3) the techniques used to minimize this variability. Based on the results, we discuss technical and other challenges that need to be overcome in order for these markers to be reliably used as outcome measures in future clinical trials. We also highlight the key points that need to be considered when designing multicenter magnetic resonance imaging studies of small vessel disease., (© The Author(s) 2016.)

Background: Vascular cognitive impairment (VCI) refers to the entire spectrum of cognitive dysfunction attributable to vascular changes in the brain. The objective of this study is to evaluate magnetic resonance imaging (MRI) correlates of performance on the National Institute of Neurological Disorders and Stroke-Canadian Stroke Network (NINDS-CSN) VCI neuropsychology protocols., Method: Fifty ischemic stroke patients and 50 normal elderly persons completed the VCI protocols and MRI. Relationships between the four cognitive domains (executive/activation, language, visuospatial, and memory) and three protocol (60-, 30-, and 5-min) summary scores with MRI measures of volumes of white matter hyperintensities (WMH) and global brain and hippocampal atrophy were assessed using linear regression., Results: All cognitive domain scores were associated with WMH volume and, with the exception of language domain, with global atrophy. Additional relationships were found between executive/activation and language domains with left hippocampal volume, visuospatial domain with right hippocampal volume, and memory domain with bilateral hippocampal volumes. All protocol summary scores showed comparable relationships with WMH and hippocampal volumes, with additional relationships found between the 60- and 30-min protocols with global brain volume., Conclusions: Performance on the NINDS-CSN VCI protocols reflects underlying volumetric brain changes implicated in cognitive dysfunctions in VCI.

The relationship between the apolipoprotein E (APOE) exon 4 polymorphism and white matter changes (WMC) in elderly subjects or patients with Alzheimer's disease is controversial. To investigate this polymorphism in relation to WMC in patients with lacunar infarcts, we prospectively observed 67 patients with acute lacunar infarct and 134 age- and sex-matched controls. Genotypes were determined using a nested polymerase chain reaction. WMC were measured quantitatively and were divided into two groups, severe and mild, with the mean volume of WMC as the cut point. Twenty-two patients (33%) had severe WMC. There was a significant difference in the distribution of APOE epsilon2, epsilon3, and epsilon4 alleles between severe and mild WMC groups (P = 0.002). The frequency of epsilon4 alleles was higher in patients with severe WMC than in those with mild WMC (25% vs. 7%, P = 0.003). These results suggest that APOE epsilon4 may exacerbate WMC in patients with lacunar infarcts. Further studies are required to confirm this finding.

Background and Purpose: Controversies still exist as to the neuroimaging determinants of cognitive impairment in cerebral small vessel disease (SVD). The authors studied the neuroimaging correlates of cognitive performances among patients with stroke associated with SVD., Methods: The authors per formed cerebral computed tomography, magnetic resonance imaging, and diffusion-weighted imaging among 74 consecutive patients admitted to the acute stroke unit because of stroke associated with SVD. They examined the association between cognitive performances and the following neuroimaging features: volume of white matter changes (WMC), multiplicity of lacunae, location of lacunae, total cerebral atrophy, and frontal and medial temporal lobe atrophy., Results: Apart from age and education, univariate linear regression analyses revealed that WMC volume, presence of thalamic lacunae, cerebral atrophy, and left frontal lobe atrophy predicted performance on the Mini-Mental State Examination while WMC volume, presence of thalamic infarcts, cerebral atrophy, and frontal lobe atrophy of both sides predicted performance on the Mattis Dementia Rating Scale-Initiation/Preservation subscale. In the multivariate analyses, education (R2=0.22, P<.001), left frontal lobe atrophy (R2=0.10, P=.004), and presence of thalamic lacunae (R2=0.04, P=.049) were found to predict performance on the Mini-Mental State Examination while age (R2=0.23, P<.001) and presence of thalamic lacunae (R2=0.08, P=.011) were found to predict performance on the Mattis Dementia Rating Scale-Initiation/Preservation., Conclusions: Among patients with stroke associated with SVD, thalamic lacunae and frontal lobe atrophy are key determinants of cognitive performances.

Background: There is growing awareness of the coexistence of Alzheimer's disease and cerebrovascular disease (AD+CVD), however, due to lack of well-defined criteria and treatment guidelines AD+CVD may be underdiagnosed in Asia.Methods: Sixteen dementia specialists from nine Asia Pacific countries completed a survey in September 2014 and met in November 2014 to review the epidemiology, diagnosis and treatment of AD+CVD in Asia. A consensus was reached by discussion, with evidence provided by published studies when available.Results: AD accounts for up to 60% and AD+CVD accounts for 10-20% of all dementia cases in Asia. The reasons for underdiagnosis of AD+CVD include lack of awareness as a result of a lack of diagnostic criteria, misdiagnosis as vascular dementia or AD, lack of diagnostic facilities, resource constraints and cost of investigations. There is variability in the tools used to diagnose AD+CVD in clinical practice. Diagnosis of AD+CVD should be performed in a stepwise manner of clinical evaluation followed by neuroimaging. Dementia patients should be assessed for cognition, behavioural and psychological symptoms, functional staging and instrumental activities of daily living. Neuroimaging should be performed using computed tomography or magnetic resonance imaging. The treatment goals are to stabilize or slow progression as well as to reduce behavioural and psychological symptoms, improve quality of life and reduce disease burden. First-line therapy is usually an acetylcholinesterase inhibitor such as donepezil.Conclusion: AD+CVD is likely to be under-recognised in Asia. Further research is needed to establish the true prevalence of this treatable and potentially preventable disease. [ABSTRACT FROM AUTHOR]

White matter hyperintensities (WMH) are common in stroke. The influence of WMH on health-related quality of life (HRQoL) following a lacunar stroke is unknown. This study evaluated the impact of WMH on HRQoL in acute lacunar stroke. A cohort of 160 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a research assistant administered the Short Form-36 (SF-36) to assess HRQoL. The severity of WMH was evaluated with magnetic resonance imaging (MRI). In univariate analysis, the severity of deep WMH (DWMH) negatively correlated with patients' vitality (VT; p < 0.05), social function (SF; p < 0.001), role-emotional (RE; p < 0.01), mental health (MH; p < 0.01), and mental component summary (MCS; p < 0.001) scores of HRQoL. DWMH was independently associated with all of the above five SF-36 scores ( p < 0.05) in linear regression analysis. These findings suggest that DWMH has a significant impact on the HRQoL of stroke survivors. The importance of DWMH in the long-term HRQoL in lacunar stroke warrants further investigation. [ABSTRACT FROM AUTHOR]

Although the age-related white matter changes (ARWMC) scale has been advocated to be applicable to both MRI and CT for assessing the severity of WMC, its inter-rater reliability on CT is only fair. We aimed to operationalize the ARWMC scale and investigate the effect of this operationalization on the reliability and validity on MRI and CT. Operational definitions of the ARWMC scale were derived from Erkinjuntti research criteria for subcortical vascular dementia and Scheltens scale. Using original and operationalized ARWMC scale, eight observers recorded the time for rating per MRI and per CT. We investigated the inter-rater and intrarater reliability as well as validity against volume using data from 97 stroke patients. Inter-rater reliability of the operationalized scale on CT (0.874, 95% confidence interval [0.780-0.934]) was better than the original scale (0.569, 95% confidence interval [0.247-0.775]). Its intrarater reliability on CT (0.869) and reliability on MRI (inter-rater: 0.860; intrarater: 0.838) was comparable with the original scale (CT intrarater: 0.750 and on MRI inter-rater: 0.845; intrarater: 0.853). The time required to administer the operationalized scale (4′2″ for MRI and 1′18″ for CT) was similar to that of the original scale (3′56″ for MRI and 1′16″ for CT). The original scale and operationalized scale also significantly correlated with WMC volume (operationalized scale ρ = 0.613, P < 0.001, original scale ρ = 0.638, P < 0.001). Operational definitions improve the inter-rater reliability of ARWMC scale on CT, and it correlates with volumetric measurement. [ABSTRACT FROM AUTHOR]

Background and Purpose: Coexisting ischemic heart disease (IHD) and concurrent atherosclerosis of intracranial and extracranial vessels is common in Asians. This study aims to investigate the long-term outcomes of ischemic stroke patients with concurrent stenoses and IHD. Methods: This was a prospective cohort study in Hong Kong. Consecutive Chinese patients with acute ischemic stroke underwent MRI, magnetic resonance angiography and carotid duplex sonography. Results: A total of 428 patients were included. The mean follow-up period was 65 months (up to 87 months). Ninety-three patients (22%) died of any cause and 104 patients (22%) suffered from nonfatal vascular events. Fifty-four patients (13%) had IHD. Among them, 27 patients (50%) had concurrent stenoses. In patients with concurrent stenoses and IHD, only 3 (11%) were free of death and recurrent vascular events. Eight (30%) had recurrent nonfatal stroke, 7 (26%) had nonfatal myocardial infarct (MI) and 11 (41%) died, 6 (22%) of them due to fatal MI. The overall 5-year cumulative rates of mortality, recurrent vascular events and combined poor outcomes were 21, 23 and 43%, respectively. In patients with concurrent stenoses and IHD, these rates were 40, 50 and 83%, respectively. More deaths (log rank: 6.56; p = 0.01), recurrent vascular events (log rank: 25.24; p < 0.001) and poor outcomes (log rank: 27.50; p < 0.001) were found among patients with concurrent stenoses and IHD. Conclusions: Ischemic stroke patients with concurrent stenoses and IHD had high risks of death and recurrent vascular events. Future studies on aggressive medical therapy and early cardiac interventions in this high-risk group of stroke patients are warranted. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]