Normal cerebral oxygen consumption and lactate levels in patients with Alzheimer's disease and Lewy body dementia.
Normal cerebral oxygen consumption and lactate levels in patients with Alzheimer's disease and Lewy body dementia.
Where did the research take place?
The study site has not been established. Author addresses may differ from where the research occurred.
Copenhagen, DK · Author affiliation
Danish Dementia Research Centre (DDRC), Department of Neurology, Copenhagen University Hospital -Rigshospitalet, Inge Lehmanns Vej 8, 2100, Copenhagen, Denmark. Christian.sandoee.musaeus@regionh.dk.Location evidence
Aalborg, DK · Author affiliation
Aalborg University, Fredrik Bajers Vej 7, Aalborg East, Denmark.Location evidence
Roskilde, DK · Author affiliation
Regional Dementia Research Centre, Department of Neurology, Zealand University Hospital, Vestermarksvej 11, 4000, Roskilde, Denmark.Location evidence
Glostrup, DK · Author affiliation
Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital - Rigshospitalet, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark.Location evidence
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Original abstract
Brain metabolism is reduced in patients with dementia disorders, as demonstrated by hypometabolism on 2-deoxy-2-[18F]fluoroglucose ([18F]FDG) positron emissions tomography. A contributing factor to the hypometabolism could be decreased cerebral blood flow (CBF) leading to a state of subtle hypoperfusion-induced tissue hypoxia causing a reduced brain oxygen metabolism and consequently elevated brain lactate. In the current exploratory study, we investigated brain lactate, global and regional CBF, and global cerebral metabolic rate of oxygen (CMRO2) in patients with Alzheimer's disease (AD) and dementia with Lewy bodies (DLBs). We hypothesized that the patients demonstrate a state of tissue hypoxia with reduced CMRO2 and elevated brain lactate concentration. Participants included 24 AD patients, 10 DLB patients, and 15 healthy controls. MR spectroscopy measured lactate in the precuneus and occipital lobe. Global CBF and venous oxygen saturation (for CMRO2 calculation) were assessed using phase-contrast and susceptibility-based oximetry MRI, respectively. Regional CBF was measured with ASL-MRI. We observed no significant difference in either brain lactate or CMRO2 between groups. The regional CBF in precuneus was significantly lower in AD compared to HC; however, this hypoperfusion was not associated with a higher lactate concentration. The lack of a difference in CMRO2 or lactate concentration between patients and controls suggests that the hypometabolism observed in patients with AD and DLB may reflect structural neurodegeneration and not a state of tissue hypoxia. The local decrease of CBF in precuneus in patients with AD may be due to a lower CBF demand due to neurodegeneration.