Structural Volume of Hippocampus and Alzheimer’s Disease

Balestrieri, João Vitor Lois; Nonato, Mahara Barbosa; Gheler, Larissa; Prandini, Mirto Nelso

doi:10.1590/1806-9282.66.4.512

Cited by 12 publications

(10 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Notably, AD tends to involve specific neural assemblies and networks that are more vulnerable to Aβ aggregates 14 . Two structures that are proposed affected in AD early stages are the entorhinal cortex (EC) 15 and hippocampus (HPC) 16 , both pivotal for proper memory functions, notably, object recognition 17 . Functional and structural changes in EC and HPC can be detected years before significant clinical symptoms, and therefore, suggested as potential biomarkers for AD diagnosis 18 .…”

Section: Introductionmentioning

confidence: 99%

Disrupted connectivity in the olfactory bulb-entorhinal cortex-dorsal hippocampus circuit is associated with recognition memory deficit in Alzheimer’s disease model

Salimi

Tabasi

Abdolsamadi

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Neural synchrony in brain circuits is the mainstay of cognition, including memory processes. Alzheimer's disease (AD) is a progressive neurodegenerative disorder that disrupts neural synchrony in specific circuits, associated with memory dysfunction before a substantial neural loss. Recognition memory impairment is a prominent cognitive symptom in the early stages of AD. The entorhinal–hippocampal circuit is critically engaged in recognition memory and is known as one of the earliest circuits involved due to AD pathology. Notably, the olfactory bulb is closely connected with the entorhinal–hippocampal circuit and is suggested as one of the earliest regions affected by AD. Therefore, we recorded simultaneous local field potential from the olfactory bulb (OB), entorhinal cortex (EC), and dorsal hippocampus (dHPC) to explore the functional connectivity in the OB-EC-dHPC circuit during novel object recognition (NOR) task performance in a rat model of AD. Animals that received amyloid-beta (Aβ) showed a significant impairment in task performance and a marked reduction in OB survived cells. We revealed that Aβ reduced coherence and synchrony in the OB-EC-dHPC circuit at theta and gamma bands during NOR performance. Importantly, our results exhibit that disrupted functional connectivity in the OB-EC-dHPC circuit was correlated with impaired recognition memory induced by Aβ. These findings can elucidate dynamic changes in neural activities underlying AD, helping to find novel diagnostic and therapeutic targets.

show abstract

Section: Introductionmentioning

confidence: 99%

Disrupted connectivity in the olfactory bulb-entorhinal cortex-dorsal hippocampus circuit is associated with recognition memory deficit in Alzheimer’s disease model

Salimi

Tabasi

Abdolsamadi

et al. 2022

Sci Rep

View full text Add to dashboard Cite

show abstract

“…We found limited studies in Latin America that utilized the MTA and PA scores for comparisons, limiting comparisons with the results of our study in a Peruvian population. One review article from Brazil summarized several articles that have utilized various MRI hippocampal measurements to identify dementia types ( 37 ). One study from Argentina used the MTA score to identify patients with AD utilizing the ATN protocol for Alzheimer's disease ( 38 ), but this study did not seek to validate the MTA in a Latin American population.…”

Section: Discussionmentioning

confidence: 99%

Combining visual rating scales to identify prodromal Alzheimer's disease and Alzheimer's disease dementia in a population from a low and middle-income country

et al. 2022

View full text Add to dashboard Cite

BackgroundMany low- and middle-income countries, including Latin America, lack access to biomarkers for the diagnosis of prodromal Alzheimer's Disease (AD; mild cognitive impairment due to AD) and AD dementia. MRI visual rating scales may serve as an ancillary diagnostic tool for identifying prodromal AD or AD in Latin America. We investigated the ability of brain MRI visual rating scales to distinguish between cognitively healthy controls, prodromal AD and AD.MethodsA cross-sectional study was conducted from a multidisciplinary neurology clinic in Lima, Peru using neuropsychological assessments, brain MRI and cerebrospinal fluid amyloid and tau levels. Medial temporal lobe atrophy (MTA), posterior atrophy (PA), white matter hyperintensity (WMH), and MTA+PA composite MRI scores were compared. Sensitivity, specificity, and area under the curve (AUC) were determined.ResultsFifty-three patients with prodromal AD, 69 with AD, and 63 cognitively healthy elderly individuals were enrolled. The median age was 75 (8) and 42.7% were men. Neither sex, mean age, nor years of education were significantly different between groups. The MTA was higher in patients with AD (p < 0.0001) compared with prodromal AD and controls, and MTA scores adjusted by age range (p < 0.0001) and PA scores (p < 0.0001) were each significantly associated with AD diagnosis (p < 0.0001) but not the WMH score (p=0.426). The MTA had better performance among ages <75 years (AUC 0.90 [0.85–0.95]), while adjusted MTA+PA scores performed better among ages>75 years (AUC 0.85 [0.79–0.92]). For AD diagnosis, MTA+PA had the best performance (AUC 1.00) for all age groups.ConclusionsCombining MTA and PA scores demonstrates greater discriminative ability to differentiate controls from prodromal AD and AD, highlighting the diagnostic value of visual rating scales in daily clinical practice, particularly in Latin America where access to advanced neuroimaging and CSF biomarkers is limited in the clinical setting.

show abstract

“…MRI T1 weighted structural images are recommended [2] and integrated [3] in routine diagnosis of Alzheimer's disease (AD). The medial temporal lobe atrophy (MTA) is the hall mark of AD in MRI images [4,5]. Radiologists use a coronal section of the T1 weighted MRI images to rate patients' MTA using a 5 points visual grading scale, based on the height of the hippocampal formation, the widths of the choroid fissure and the temporal horn [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…The medial temporal lobe atrophy (MTA) is the hall mark of AD in MRI images [4,5]. Radiologists use a coronal section of the T1 weighted MRI images to rate patients' MTA using a 5 points visual grading scale, based on the height of the hippocampal formation, the widths of the choroid fissure and the temporal horn [4][5][6]. A score of 3 or above is considered abnormal [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…Radiologists use a coronal section of the T1 weighted MRI images to rate patients' MTA using a 5 points visual grading scale, based on the height of the hippocampal formation, the widths of the choroid fissure and the temporal horn [4][5][6]. A score of 3 or above is considered abnormal [4][5][6]. A diagnostic sensitivity and specificity of 85% can be achieved by the best radiologists using visual scale grading [6] without using the patients' other information.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Computer assisted diagnosis of Alzheimer’s disease using statistical likelihood-ratio test

et al. 2023

View full text Add to dashboard Cite

The purpose of this work is to present a computer assisted diagnostic tool for radiologists in their diagnosis of Alzheimer’s disease. A statistical likelihood-ratio procedure from signal detection theory was implemented in the detection of Alzheimer’s disease. The probability density functions of the likelihood ratio were constructed by using medial temporal lobe (MTL) volumes of patients with Alzheimer’s disease (AD) and normal controls (NC). The volumes of MTL as well as other anatomical regions of the brains were calculated by the FreeSurfer software using T1 weighted MRI images. The MRI images of AD and NC were downloaded from the database of Alzheimer’s disease neuroimaging initiative (ADNI). A separate dataset of minimal interval resonance imaging in Alzheimer’s disease (MIRIAD) was used for diagnostic testing. A sensitivity of 89.1% and specificity of 87.0% were achieved for the MIRIAD dataset which are better than the 85% sensitivity and specificity achieved by the best radiologists without input of other patient information.

show abstract

Structural Volume of Hippocampus and Alzheimer’s Disease

Cited by 12 publications

References 9 publications

Disrupted connectivity in the olfactory bulb-entorhinal cortex-dorsal hippocampus circuit is associated with recognition memory deficit in Alzheimer’s disease model

Disrupted connectivity in the olfactory bulb-entorhinal cortex-dorsal hippocampus circuit is associated with recognition memory deficit in Alzheimer’s disease model

Combining visual rating scales to identify prodromal Alzheimer's disease and Alzheimer's disease dementia in a population from a low and middle-income country

Computer assisted diagnosis of Alzheimer’s disease using statistical likelihood-ratio test

Contact Info

Product

Resources

About