The Cingulate Island Sign on FDG‐PET vs. IMP‐SPECT to Assess Mild Cognitive Impairment in Alzheimer's Disease vs. Dementia with Lewy Bodies

2019 ◽  
Vol 29 (6) ◽  
pp. 712-720 ◽  
Author(s):  
Yuhei Chiba ◽  
Hiroshige Fujishiro ◽  
Eizo Iseki ◽  
Koji Kasanuki ◽  
Kiyoshi Sato
2014 ◽  
Vol 25 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Bing Zhang ◽  
Tanis J. Ferman ◽  
Bradley F. Boeve ◽  
Glenn E. Smith ◽  
Mandie Maroney-Smith ◽  
...  

Brain ◽  
2021 ◽  
Author(s):  
Julia Schumacher ◽  
Nicola J Ray ◽  
Calum A Hamilton ◽  
Paul C Donaghy ◽  
Michael Firbank ◽  
...  

Abstract Dementia with Lewy bodies and Alzheimer’s disease show early degeneration of the cholinergic nucleus basalis of Meynert. However, how white matter projections between the nucleus basalis of Meynert and the cortex are altered in neurodegenerative disease is unknown. Tractography of white matter pathways originating from the nucleus basalis of Meynert was performed using diffusion-weighted imaging in 46 Alzheimer’s disease dementia, 48 dementia with Lewy bodies, 35 mild cognitive impairment with Alzheimer’s disease, 38 mild cognitive impairment with Lewy bodies, and 71 controls. Mean diffusivity of the resulting pathways was compared between groups and related to cognition, attention, functional EEG changes, and dementia conversion in the mild cognitive impairment groups. We successfully tracked a medial and a lateral pathway from the nucleus basalis of Meynert. Mean diffusivity of the lateral pathway was higher in both dementia and mild cognitive impairment groups than controls (all P < 0.03). In the patient groups, increased mean diffusivity of this pathway was related to more impaired global cognition (β=-0.22, P = 0.06) and worse performance on an attention task (β = 0.30, P = 0.03). In patients with mild cognitive impairment, loss of integrity of both nucleus basalis of Meynert pathways was associated with increased risk of dementia progression (hazard ratio [95% confidence interval], medial pathway: 2.51 [1.24–5.09]; lateral pathway: 2.54 [1.24–5.19]). Nucleus basalis of Meynert volume was reduced in all clinical groups compared to controls (all P < 0.001), but contributed less strongly to cognitive impairment and was not associated with attention or dementia conversion. EEG slowing in the patient groups as assessed by a decrease in dominant frequency was associated with smaller nucleus basalis of Meynert volumes (β = 0.22, P = 0.02) and increased mean diffusivity of the lateral pathway (β=-0.47, P = 0.003). We show that degeneration of the cholinergic nucleus basalis of Meynert in Alzheimer’s disease and dementia with Lewy bodies is accompanied by an early reduction in integrity of white matter projections that originate from this structure. This is more strongly associated with cognition and attention than the volume of the nucleus basalis of Meynert itself and might be an early indicator of increased risk of dementia conversion in people with mild cognitive impairment.


Author(s):  
Tahreem Ghazal Siddiqui ◽  
Timothy Whitfield ◽  
Sudhakar Janaki Praharaju ◽  
Dilman Sadiq ◽  
Hiba Kazmi ◽  
...  

<b><i>Introduction:</i></b> Fifteen percent of people with mild cognitive impairment (MCI) will progress to dementia within 2 years. There is increasing focus on the evaluation of biomarkers which point towards the underlying pathology. This enables better prediction of clinical outcomes. Early diagnosis of the dementia subtype is crucial for appropriate management and accurate prognosis. The aim of this study was to compare MRI measures in stable mild cognitive impairment patients (stable-MCI), prodromal Alzheimer’s disease (pro-AD), and prodromal dementia with Lewy bodies (pro-DLB). <b><i>Methods:</i></b> Out of 1,814 patients assessed in Essex memory clinic between 2002 and 2017, 424 had MCI at baseline with follow-up data. All patients underwent comprehensive clinical and cognitive assessment at each assessment. MRI scans were acquired at patients’ baseline assessment, corresponding to the time of initial MCI clinical diagnosis. Patients were grouped according to their diagnosis at the end of follow-up. All baseline scans were visually rated according to established rating scales for medial temporal atrophy (MTA), global cortical atrophy (GCA), and white matter lesions (WMLs). <b><i>Results:</i></b> MRI scans were available for 28 pro-DLB patients and were matched against 27 pro-AD and 28 stable-MCI patients for age, sex, and education. The mean follow-up duration was 34 months for the pro-AD group, 27 months for the pro-DLB group, and 21 months for the stable-MCI group. MTA scores were significantly greater in pro-AD patients compared to pro-DLB (<i>p</i> = 0.047) and stable-MCI patients (<i>p</i> = 0.012). There was no difference on GCA or WMLs between pro-AD, pro-DLB, and stable-MCI. <b><i>Conclusions:</i></b> This study indicates that a simple visual rating of MTA at the stage of MCI already differs at a group level between patients that progress to AD, DLB, or continue to be stable-MCI. This could aid clinicians to differentiate between MCI patients who are likely to develop AD, versus those who might progress to DLB or remain stable.


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