scholarly journals Presumptive spontaneous brain microhemorrhages in geriatric dogs: a comparative retrospective MRI study of dogs with and without evidence of canine cognitive dysfunction

2019 ◽  
Author(s):  
Curtis W Dewey ◽  
Mark Rishniw ◽  
Philippa J Johnson ◽  
Emma S Davies ◽  
Joseph J Sackman ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Dysfunction ◽  
Clinical Evidence ◽  
Brain Volume ◽  
Brain Mri ◽  
Mri Findings ◽  
Total Brain Volume ◽  
Recent Onset ◽  
Total Brain ◽  
Mri Study

The objective of this study was to compare specific brain MRI anatomic measurements between three groups of geriatric ( > 8yrs) dogs: 1) neurologically impaired dogs with presumptive spontaneous brain microhemorrhages and no clinical evidence of canine cognitive dysfunction 2) dogs with canine cognitive dysfunction 3) dogs without clinical evidence of cognitive impairment or abnormalities on neurologic examination (control dogs). MR images from 46 geriatric dogs were reviewed and measurements were obtained of interthalamic adhesion height (thickness) and mid-sagittal interthalamic adhesion area for all dogs, in addition to total brain volume. Interthalamic adhesion measurements, either absolute or normalized to total brain volume were compared between groups. Signalment (age, breed, sex), body weight, presence and number of SBMs, as well as other abnormal MRI findings were recorded for all dogs. All interthalamic adhesion measurement parameters were significantly (p<0.05) different between control dogs and affected dogs. Both dogs with cognitive dysfunction (12/13; 92 %) and dogs with isolated brain microhemorrhages had more microhemorrhages than control dogs (3/19; 16%). Affected dogs without cognitive dysfunction had more microhemorrhages than dogs with cognitive dysfunction. In addition to signs of cognitive impairment for the CCD group, main clinical complaints for SBM and CCD dogs were referable to central vestibular dysfunction, recent-onset seizure activity, or both. Geriatric dogs with spontaneous brain microhemorrhages without cognitive dysfunction have similar MRI abnormalities as dogs with cognitive dysfunction but may represent a distinct diseasecategory.

scholarly journals Presumptive spontaneous brain microhemorrhages in geriatric dogs: a comparative retrospective MRI study of dogs with and without evidence of canine cognitive dysfunction

2019 ◽  
Author(s):  
Curtis W Dewey ◽  
Mark Rishniw ◽  
Philippa J Johnson ◽  
Emma S Davies ◽  
Joseph J Sackman ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Dysfunction ◽  
Clinical Evidence ◽  
Brain Volume ◽  
Brain Mri ◽  
Mri Findings ◽  
Total Brain Volume ◽  
Recent Onset ◽  
Total Brain ◽  
Mri Study

The objective of this study was to compare specific brain MRI anatomic measurements between three groups of geriatric ( > 8yrs) dogs: 1) neurologically impaired dogs with presumptive spontaneous brain microhemorrhages and no clinical evidence of canine cognitive dysfunction 2) dogs with canine cognitive dysfunction 3) dogs without clinical evidence of cognitive impairment or abnormalities on neurologic examination (control dogs). MR images from 46 geriatric dogs were reviewed and measurements were obtained of interthalamic adhesion height (thickness) and mid-sagittal interthalamic adhesion area for all dogs, in addition to total brain volume. Interthalamic adhesion measurements, either absolute or normalized to total brain volume were compared between groups. Signalment (age, breed, sex), body weight, presence and number of SBMs, as well as other abnormal MRI findings were recorded for all dogs. All interthalamic adhesion measurement parameters were significantly (p<0.05) different between control dogs and affected dogs. Both dogs with cognitive dysfunction (12/13; 92 %) and dogs with isolated brain microhemorrhages had more microhemorrhages than control dogs (3/19; 16%). Affected dogs without cognitive dysfunction had more microhemorrhages than dogs with cognitive dysfunction. In addition to signs of cognitive impairment for the CCD group, main clinical complaints for SBM and CCD dogs were referable to central vestibular dysfunction, recent-onset seizure activity, or both. Geriatric dogs with spontaneous brain microhemorrhages without cognitive dysfunction have similar MRI abnormalities as dogs with cognitive dysfunction but may represent a distinct diseasecategory.

scholarly journals Interthalamic adhesion size in aging dogs with presumptive spontaneous brain microhemorrhages: a comparative retrospective MRI study of dogs with and without evidence of canine cognitive dysfunction

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9012
Author(s):  
Curtis W. Dewey ◽  
Mark Rishniw ◽  
Philippa J. Johnson ◽  
Emma S. Davies ◽  
Joseph J. Sackman ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Cognitive Dysfunction ◽  
Brain Atrophy ◽  
Clinical Evidence ◽  
Brain Volume ◽  
Mri Findings ◽  
Disease Category ◽  
Total Brain Volume ◽  
Recent Onset ◽  
Total Brain

Objective Spontaneous brain microhemorrhages in elderly people are present to some degree in Alzheimer’s disease patients but have been linked to brain atrophy in the absence of obvious cognitive decline. Brain microhemorrhages have recently been described in older dogs, but it is unclear whether these are associated with brain atrophy. Diminution of interthalamic adhesion size-as measured on MRI or CT-has been shown to be a reliable indicator of brain atrophy in dogs with canine cognitive dysfunction (CCD) in comparison with successfully aging dogs. We hypothesized that aging dogs with brain microhemorrhages presenting for neurologic dysfunction but without obvious features of cognitive decline would have small interthalamic adhesion measurements, like dogs with CCD, compared with control dogs. The objective of this study was to compare interthalamic adhesion size between three groups of aging (>9 years) dogs: (1) neurologically impaired dogs with presumptive spontaneous brain microhemorrhages and no clinical evidence of cognitive dysfunction (2) dogs with CCD (3) dogs without clinical evidence of encephalopathy on neurologic examination (control dogs). MR images from 52 aging dogs were reviewed and measurements were obtained of interthalamic adhesion height (thickness) and mid-sagittal interthalamic adhesion area for all dogs, in addition to total brain volume. Interthalamic adhesion measurements, either absolute or normalized to total brain volume were compared between groups. Signalment (age, breed, sex), body weight, presence and number of SBMs, as well as other abnormal MRI findings were recorded for all dogs. Results All interthalamic adhesion measurement parameters were significantly (P < 0.05) different between control dogs and affected dogs. Both dogs with cognitive dysfunction (12/15; 80%) and dogs with isolated brain microhemorrhages had more microhemorrhages than control dogs (3/25; 12%). Affected dogs without cognitive dysfunction had significantly more microhemorrhages than dogs with cognitive dysfunction. In addition to signs of cognitive impairment for the CCD group, main clinical complaints for SBM and CCD dogs were referable to central vestibular dysfunction, recent-onset seizure activity, or both. Geriatric dogs with spontaneous brain microhemorrhages without cognitive dysfunction have similar MRI abnormalities as dogs with cognitive dysfunction but may represent a distinct disease category.

scholarly journals Atrial Fibrillation and Brain Magnetic Resonance Imaging Abnormalities

Stroke ◽  
2019 ◽  
Vol 50 (4) ◽  
pp. 783-788 ◽  
Author(s):  
Jeremy P. Berman ◽  
Faye L. Norby ◽  
Thomas Mosley ◽  
Elsayed Z. Soliman ◽  
Rebecca F. Gottesman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Brain Volume ◽  
Brain Mri ◽  
Brain Magnetic Resonance Imaging ◽  
White Matter Hyperintensity ◽  
Resonance Imaging ◽  
Total Brain Volume ◽  
Cross Sectional ◽  
Total Brain ◽  
Sectional Analysis

Background and Purpose— Atrial fibrillation (AF) is associated with dementia independent of clinical stroke. The mechanisms underlying this association remain unclear. In a community-based cohort, the ARIC study (Atherosclerosis Risk in Communities), we evaluated (1) the longitudinal association of incident AF and (2) the cross-sectional association of prevalent AF with brain magnetic resonance imaging (MRI) abnormalities. Methods— The longitudinal analysis included 963 participants (mean age, 73±4.4 years; 62% women; 51% black) without prevalent stroke or AF who underwent a brain MRI in 1993 to 1995 and a second MRI in 2004 to 2006 (mean, 10.6±0.8 years). Outcomes included subclinical cerebral infarctions, sulcal size, ventricular size, and, for the cross-sectional analysis, white matter hyperintensity volume and total brain volume. Results— In the longitudinal analysis, 29 (3.0%) participants developed AF after the first brain MRI. Those who developed AF had higher odds of increase in subclinical cerebral infarctions (odds ratio [OR], 3.08; 95% CI, 1.39–6.83), worsening sulcal grade (OR, 3.56; 95% CI, 1.04–12.2), and worsening ventricular grade (OR, 9.34; 95% CI, 1.24–70.2). In cross-sectional analysis, of 969 participants, 35 (3.6%) had prevalent AF at the time of the 2004 to 2006 MRI scan. Those with AF had greater odds of higher sulcal (OR, 3.9; 95% CI, 1.7–9.1) and ventricular grade (OR, 2.4; 95% CI, 1.0–5.7) after multivariable adjustment and no difference in white matter hyperintensity or total brain volume. Conclusions— AF is independently associated with increase in subclinical cerebral infarction and worsening sulcal and ventricular grade—morphological changes associated with aging and dementia. More research is needed to define the mechanisms underlying AF-related neurodegeneration.

scholarly journals Canine cognitive dysfunction (CCD) patients have reduced total hippocampal volume compared with aging control dogs: a comparative MRI study

2020 ◽  
Author(s):  
Curtis Wells Dewey ◽  
Mark Rishniw ◽  
Simon Platt ◽  
Kelsey Robinson ◽  
Joseph Sackman ◽  
...  
Keyword(s):  
Cognitive Dysfunction ◽  
Hippocampal Volume ◽  
Hippocampal Atrophy ◽  
Pathological Feature ◽  
Volumetric Mri ◽  
Total Brain Volume ◽  
Brain Volumes ◽  
Disease Mechanisms ◽  
Total Brain ◽  
Mri Study

AbstractHippocampal atrophy is a key pathologic and MRI feature of human Alzheimer’s disease (AD). Hippocampal atrophy has not been documented via MRI in canine cognitive dysfunction (CCD), which is considered the dog model of human AD. The purpose of this retrospective comparative volumetric MRI study was to compare total hippocampal volumes between successfully aging (control) dogs and dogs diagnosed with CCD. Mimics® software was used to derive total hippocampal volumes and total brain volumes from the MRI studies of 42 aging dogs (≥ 9 years): 16 dogs diagnosed with CCD and 26 successfully aging controls. Total hippocampal volume normalized to total brain volume was significantly less for CCD patients compared with control dogs (p=0.04). The results of this study suggest that-similar to human AD-hippocampal atrophy is a pathological feature of CCD. This finding has potential importance for both investigating disease mechanisms related to dementia as well as future hippocampal-targeted therapies.

scholarly journals Plasma Metabolites Associated with Brain MRI Measures of Neurodegeneration in Older Adults in the Atherosclerosis Risk in Communities–Neurocognitive Study (ARIC-NCS)

2019 ◽  
Vol 20 (7) ◽  
pp. 1744
Author(s):  
Danni Li ◽  
Jeffrey Misialek ◽  
Clifford Jack ◽  
Michelle Mielke ◽  
David Knopman ◽  
...  
Keyword(s):  
Older Adults ◽  
Physical Function ◽  
Brain Volume ◽  
Brain Mri ◽  
Plasma Metabolites ◽  
Total Brain Volume ◽  
Atherosclerosis Risk In Communities ◽  
Mri Features ◽  
Total Brain ◽  
Atherosclerosis Risk

Background: Plasma metabolites are associated with cognitive and physical function in the elderly. Because cerebral small vessel disease (SVD) and neurodegeneration are common causes of cognitive and physical function decline, the primary objective of this study was to investigate the associations of six plasma metabolites (two plasma phosphatidylcholines [PCs]: PC aa C36:5 and PC aa 36:6 and four sphingomyelins [SMs]: SM C26:0, SM [OH] C22:1, SM [OH] C22:2, SM [OH] C24:1) with magnetic resonance imaging (MRI) features of cerebral SVD and neurodegeneration in older adults. Methods: This study included 238 older adults in the Atherosclerosis Risk in Communities study at the fifth exam. Multiple linear regression was used to assess the association of each metabolite (log-transformed) in separate models with MRI measures except lacunar infarcts, for which binary logistic regression was used. Results: Higher concentrations of plasma PC aa C36:5 had adverse associations with MRI features of cerebral SVD (odds ratio of 1.69 [95% confidence interval: 1.01, 2.83] with lacunar infarct, and beta of 0.16 log [cm3] [0.02, 0.30] with log [White Matter Hyperintensities (WMH) volume]) while higher concentrations of 3 plasma SM (OH)s were associated with higher total brain volume (beta of 12.0 cm3 [5.5, 18.6], 11.8 cm3 [5.0, 18.6], and 7.3 cm3 [1.2, 13.5] for SM [OH] C22:1, SM [OH] C22:2, and SM [OH] C24:1, respectively). Conclusions: This study identified associations between certain plasma metabolites and brain MRI measures of SVD and neurodegeneration in older adults, particularly higher SM (OH) concentrations with higher total brain volume.

scholarly journals Age-Specific Adult Rat Brain MRI Templates and Tissue Probability Maps

2022 ◽  
Vol 15 ◽  
Author(s):  
Eilidh MacNicol ◽  
Paul Wright ◽  
Eugene Kim ◽  
Irene Brusini ◽  
Oscar Esteban ◽  
...  
Keyword(s):  
Rat Brain ◽  
Gray Matter ◽  
Structural Changes ◽  
Brain Volume ◽  
Brain Mri ◽  
Subcortical Structures ◽  
Total Brain Volume ◽  
Adult Rat ◽  
Probability Maps ◽  
Total Brain

Age-specific resources in human MRI mitigate processing biases that arise from structural changes across the lifespan. There are fewer age-specific resources for preclinical imaging, and they only represent developmental periods rather than adulthood. Since rats recapitulate many facets of human aging, it was hypothesized that brain volume and each tissue's relative contribution to total brain volume would change with age in the adult rat. Data from a longitudinal study of rats at 3, 5, 11, and 17 months old were used to test this hypothesis. Tissue volume was estimated from high resolution structural images using a priori information from tissue probability maps. However, existing tissue probability maps generated inaccurate gray matter probabilities in subcortical structures, particularly the thalamus. To address this issue, gray matter, white matter, and CSF tissue probability maps were generated by combining anatomical and signal intensity information. The effects of age on volumetric estimations were then assessed with mixed-effects models. Results showed that herein estimation of gray matter volumes better matched histological evidence, as compared to existing resources. All tissue volumes increased with age, and the tissue proportions relative to total brain volume varied across adulthood. Consequently, a set of rat brain templates and tissue probability maps from across the adult lifespan is released to expand the preclinical MRI community's fundamental resources.

scholarly journals Canine cognitive dysfunction patients have reduced total hippocampal volume compared with aging control dogs: A comparative magnetic resonance imaging study

2021 ◽  
Vol 10 (4) ◽  
pp. 438-442
Author(s):  
Curtis Wells Dewey ◽  
Mark Rishniw ◽  
Philippa J. Johnson ◽  
Simon Platt ◽  
Kelsey Robinson ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Cognitive Dysfunction ◽  
Brain Volume ◽  
Hippocampal Volume ◽  
Hippocampal Atrophy ◽  
Pathological Feature ◽  
Resonance Imaging ◽  
Total Brain Volume ◽  
Total Brain

Background: Hippocampal atrophy is a key pathologic and magnetic resonance imaging (MRI) feature of human Alzheimer’s disease (AD). Hippocampal atrophy has not been documented via MRI in canine cognitive dysfunction (CCD), which is considered as the dog model of human AD.Aim: The purpose of this retrospective comparative volumetric MRI study was to compare total hippocampal volumes between successfully aging (control) dogs and dogs diagnosed with CCD.Methods: Mimics® software was used to derive total hippocampal volumes and total brain volumes from the MRI studies of 42 aging dogs (≥ 9 years): 16 dogs diagnosed with CCD and 26 successfully aging controls. Hippocampal volumes were normalized to total brain volume and these values were compared between groups using Mann–Whitney U tests.Results: Total hippocampal volume normalized to total brain volume was significantly less for CCD patients compared with control dogs (p = 0.04).Conclusion: The results of this study suggest that – similar to human AD – hippocampal atrophy is a pathological feature of CCD. This finding has potential importance for both investigating disease mechanisms related to dementia as well as future hippocampal-targeted therapies.

scholarly journals Brain imaging correlates of general intelligence in UK Biobank

2019 ◽  
Author(s):  
SR Cox ◽  
SJ Ritchie ◽  
C Fawns-Ritchie ◽  
EM Tucker-Drob ◽  
IJ Deary
Keyword(s):  
White Matter ◽  
Brain Structure ◽  
Brain Volume ◽  
Brain Mri ◽  
Cognitive Test ◽  
General Factor ◽  
General Intelligence ◽  
Uk Biobank ◽  
Total Brain Volume ◽  
Total Brain

AbstractThe associations between indices of brain structure and measured intelligence are not clear. In part, this is because the evidence to date comes from mostly small and heterogenous studies. Here, we report brain structure-intelligence associations on a large sample from the UK Biobank study. The overall N = 29,004, with N = 18,363 participants providing both brain MRI and cognitive data, and a minimum N = 7318 providing the MRI data alongside a complete four-test battery. Participants’ age range was 44-81 years (M = 63.13, SD = 7.48). A general factor of intelligence (g) was extracted from four varied cognitive tests, accounting for one third of the variance in the cognitive test scores. The association between (age-and sex-corrected) total brain volume and a latent factor of general intelligence is r = 0.275, 95% C.I. = [0.252, 0.299]. A model that incorporated multiple global measures of grey and white matter macro-and microstructure accounted for more than double the g variance in older participants compared to those in middle-age (13.4% and 5.9%, respectively). There were no sex differences in the magnitude of associations between g and total brain volume or other global aspects of brain structure. The largest brain regional correlates of g were volumes of the insula, frontal, anterior/superior and medial temporal, posterior and paracingulate, lateral occipital cortices, thalamic volume, and the white matter microstructure of thalamic and association fibres, and of the forceps minor.

scholarly journals Mediterranean-type diet and brain structural change from 73 to 76 years in a Scottish cohort

Neurology ◽  
2017 ◽  
Vol 88 (5) ◽  
pp. 449-455 ◽  
Author(s):  
Michelle Luciano ◽  
Janie Corley ◽  
Simon R. Cox ◽  
Maria C. Valdés Hernández ◽  
Leone C.A. Craig ◽  
...  
Keyword(s):  
Cortical Thickness ◽  
Gray Matter ◽  
Brain Volume ◽  
Gray Matter Volume ◽  
Brain Mri ◽  
Total Brain Volume ◽  
Cross Sectional ◽  
Brain Volumes ◽  
Total Brain ◽  
Lower Adherence

Objective:To assess the association between Mediterranean-type diet (MeDi) and change in brain MRI volumetric measures and mean cortical thickness across a 3-year period in older age (73–76 years).Methods:We focused on 2 longitudinal brain volumes (total and gray matter; n = 401 and 398, respectively) plus a longitudinal measurement of cortical thickness (n = 323), for which the previous cross-sectional evidence of an association with the MeDi was strongest. Adherence to the MeDi was calculated from data gathered from a food frequency questionnaire at age 70, 3 years prior to the baseline imaging data collection.Results:In regression models adjusting for relevant demographic and physical health indicators, we found that lower adherence to the MeDi was associated with greater 3-year reduction in total brain volume (explaining 0.5% of variance, p < 0.05). This effect was half the size of the largest covariate effect (i.e., age). Cross-sectional associations between MeDi and baseline MRI measures in 562 participants were not significant. Targeted analyses of meat and fish consumption did not replicate previous associations with total brain volume or total gray matter volume.Conclusions:Lower adherence to the MeDi in an older Scottish cohort is predictive of total brain atrophy over a 3-year interval. Fish and meat consumption does not drive this change, suggesting that other components of the MeDi or, possibly, all of its components in combination are responsible for the association.

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