Links Between Metabolic and Structural Changes in the Brain of Cognitively Normal Older Adults: A 4-Year Longitudinal Follow-Up.

We aimed to longitudinally assess the relationship between changing brain energy metabolism (glucose and acetoacetate) and cognition during healthy aging. Participants aged 71 ± 5 year underwent cognitive evaluation and quantitative positron emission tomography (PET) and magnetic resonance imaging (MRI) scans at baseline ( = 25) and two ( = 25) and four ( = 16) years later. During the follow-up, the rate constant for brain extraction of glucose (K) declined by 6%-12% mainly in the temporo-parietal lobes and cingulate gyri ( ≤ 0.

68Ga-DOTATATE Uptake in Ischemic Stroke.

A 76-year-old man known to have a pancreatic neuroendocrine tumor with hepatic and lymph nodes metastasis had a follow-up Ga-DOTATATE PET/CT before Lu-DOTATATE therapy. A new cerebral lesion expressing somatostatin receptors was discovered in the right temporal lobe, suggestive of an ischemic stroke territory. This was later confirmed from the hospital chart where an ischemic stroke was described a month ago.

A 3-Month Aerobic Training Program Improves Brain Energy Metabolism in Mild Alzheimer's Disease: Preliminary Results from a Neuroimaging Study.

Background: Aerobic training has some benefits for delaying the onset or progression of Alzheimer's disease (AD). Little is known about the implication of the brain's two main fuels, glucose and ketones (acetoacetate), associated with thesebenefits.

Objective: To determine whether aerobic exercise training modifies brain energy metabolism in mild AD.

Lower brain 18F-fluorodeoxyglucose uptake but normal 11C-acetoacetate metabolism in mild Alzheimer's disease dementia.

Background: The cerebral metabolic rate of glucose (CMRg) is lower in specific brain regions in Alzheimer's disease (AD). The ketones, acetoacetate and β-hydroxybutyrate, are the brain's main alternative energy substrates to glucose.

Objective: To gain insight into brain fuel metabolism in mild AD dementia by determining whether the regional CMR and the rate constant of acetoacetate (CMRa and Ka, respectively) reflect the same metabolic deficit reported for cerebral glucose uptake (CMRg and Kg).

Glucose hypometabolism is highly localized, but lower cortical thickness and brain atrophy are widespread in cognitively normal older adults.

Several studies have suggested that glucose hypometabolism may be present in specific brain regions in cognitively normal older adults and could contribute to the risk of subsequent cognitive decline. However, certain methodological shortcomings, including a lack of partial volume effect (PVE) correction or insufficient cognitive testing, confound the interpretation of most studies on this topic. We combined [(18)F]fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) and magnetic resonance (MR) imaging to quantify cerebral metabolic rate of glucose (CMRg) as well as cortical volume and thickness in 43 anatomically defined brain regions from a group of cognitively normal younger (25 ± 3 yr old; n = 25) and older adults (71 ± 9 yr old; n = 31).

Assessment of inflammation in large arteries with 18F-FDG-PET in elderly.

This paper presents repeated measurements of atherosclerosis using bimodality positron emission tomography and computed tomography (PET/CT) with 18F-fluorodeoxyglucose (18F-FDG) to assess its uptake in aorta, iliac and femoral arteries in three groups of elderly subjects classified as normals (N), hypercholesterolemics (H) and with stable angina (A) in a 12 months follow-up (T0 to T12). The subjects in group H were taking rosuvastatin (20mg/d) for 12 months before the second scan. The calcifications in the arteries were determined by CT imaging and the artery PET images were analyzed slice by slice.

Complete normalization of severe brain 18F-FDG hypometabolism following electroconvulsive therapy in a major depressive episode.

We describe a patient with a complex neuropsychiatric disorder who presented a severe and diffuse cerebral glucose hypometabolism on (18)F-FDG PET initially which, in the clinical setting, was suspicious of an advanced neurodegenerative disease. Further evaluation suggested a major depressive episode with agitation and poor response to medication. Electroconvulsive therapy (ECT) brought excellent results.

Brain fuel metabolism, aging, and Alzheimer's disease.

Lower brain glucose metabolism is present before the onset of clinically measurable cognitive decline in two groups of people at risk of Alzheimer's disease--carriers of apolipoprotein E4, and in those with a maternal family history of AD. Supported by emerging evidence from in vitro and animal studies, these reports suggest that brain hypometabolism may precede and therefore contribute to the neuropathologic cascade leading to cognitive decline in AD. The reason brain hypometabolism develops is unclear but may include defects in brain glucose transport, disrupted glycolysis, and/or impaired mitochondrial function.

The value of PET in mild cognitive impairment, typical and atypical/unclear dementias: A retrospective memory clinic study.

This retrospective study examined the role of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis of atypical/unclear dementias in a memory clinic setting. A total of 94 patients with a diagnosis of mild cognitive impairment (MCI) or dementia, who had a PET study within 2 months of their diagnosis, were reevaluated at 5 and 18 months. Results showed that PET was associated with a change in diagnosis in 29% of patients and a 64% increase in the use of cholinesterase inhibitors (ChEIs).

Autopsy as gold standard in FDG-PET studies in dementia.

Positron emission tomography (PET) imaging with F18-fluorodeoxyglucose (FDG) is increasingly used as an adjunct to clinical evaluation in the diagnosis of dementia. Considering that most FDG-PET studies in dementia use clinical diagnosis as gold standard and that clinical diagnosis is approximately 80% sensitive or accurate, we aim to review the evidence-based data on the diagnostic accuracy of brain FDG-PET in dementia when cerebral autopsy is used as gold standard. We searched the PubMed and Medline databases for dementia-related articles that correlate histopathological diagnosis at autopsy with FDG-PET imaging and found 47 articles among which there were only 5 studies of 20 patients or more.

Psychogenic or neurogenic origin of agrammatism and foreign accent syndrome in a bipolar patient: a case report.

Background: Foreign accent syndrome (FAS) is a rare speech disorder characterized by the appearance of a new accent, different from the speaker's native language and perceived as foreign by the speaker and the listener. In most of the reported cases, FAS follows stroke but has also been found following traumatic brain injury, cerebral haemorrhage and multiple sclerosis. In very few cases, FAS was reported in patients presenting with psychiatric disorders but the link between this condition and FAS was confirmed in only one case.

18F-FDG PET in children with lymphomas.

Purpose: The aim of this study was to retrospectively evaluate the performance of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) in children with lymphomas, at various stages of their disease.

Methods: Twenty-eight children (mean age 12.5 years, 14 girls, 14 boys) with Hodgkin's disease (HD, n=17) or non-Hodgkin's lymphoma (NHL, n=11) were evaluated.

Within-patient variability of (18)F-FDG: standardized uptake values in normal tissues.

Unlabelled: The aim of this study was to evaluate the test-retest variability of standardized uptake values (SUVs) in normal tissues and the impact of various methods for measuring the SUV.

Methods: SUVs were determined in 70 cancer-free patients (40 female and 30 male) on 2 occasions an average of 271 d apart. Mean values for body weight and height, blood glucose level, injected dose, and uptake period did not change between the 2 groups of studies.