Abnormal neurotransmitter metabolite levels in Alzheimer patients with a delirium.
BACKGROUND
Delirium is a complex neuropsychiatric syndrome with an acute onset and fluctuating course. Several studies have suggested the presence of disturbed cholinergic, dopaminergic and serotonergic pathways in delirium as well as in Alzheimer's disease. Abnormal concentrations of amino acids and of neurotransmitter metabolites have been found in plasma, platelets and cerebrospinal fluid of AD patients, and in plasma and CSF of patients with a delirium. The aim of this study was to investigate amino acid and neurotransmitter metabolite levels in plasma of AD patients with a concurrent delirium.


METHODS
In a case-control study of patients suffering from Alzheimer's disease (AD) with concurrent delirium, we investigated the contribution of delirium to some biochemical parameters in blood. We compared plasma amino acid and neurotransmitter metabolite levels of 17 delirious AD patients with those of 17 age- and gender-matched non-delirious AD patients and 29 age- and gender-matched controls.


RESULTS
Homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) levels were higher in delirious AD patients than in controls, but only HVA concentrations were higher in delirious AD patients than in non-delirious AD patients.


CONCLUSIONS
Our findings suggest that central dopaminergic and serotonergic turnover are increased in AD patients with delirium and that the high dopaminergic turnover might reflect the consequences of delirium.
van der Cammen
Tischa J M
TJ
Section of Geriatric Medicine, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands. t.vandercammen@erasmusmc.nl
Tiemeier
Henning
H
Engelhart
Marianne J
MJ
Fekkes
Durk
D
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000523:psychology*; D000596:Amino Acids / Q000097:blood; D016022:Case-Control Studies; D003693:Delirium / Q000097:blood / Q000209:etiology*; D005260:Female; D006719:Homovanillic Acid / Q000097:blood; D006760:Hospitalization; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000097:blood; D008297:Male; D018377:Neurotransmitter Agents / Q000097:blood*; D011569:Psychiatric Status Rating Scales
D000596:Amino Acids; D018377:Neurotransmitter Agents; D006897:Hydroxyindoleacetic Acid; D006719:Homovanillic Acid