Cerebrospinal fluid homovanillic acid is correlated to psychotic features in neurological patients with delirium.
OBJECTIVE
The aim of this study was to determine if cerebrospinal fluid (CSF) levels of homovanillic acid (HVA) are related to the clinical features of delirium in a group of patients with acute onset neurological illness.


METHODS
Fifty-one patients with probable acute brain infection were classified as delirious and nondelirious according to Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition (DSM-IV) and Delirium Rating Scale (DRS). CSF HVA concentration was analyzed by high-performance liquid chromatography.


RESULTS
Delirium was present in 60.8% of the total sample. HVA levels were not significantly different between delirious and nondelirious patients. Remarkably, patients with psychotic symptoms shown higher levels of CSF HVA as compared to nonpsychotic patient values. In addition, HVA levels were positively correlated to specific items of DRS such as delusions (r=0.463, P=.001), hallucinations (r=0.438, P=.001), cognitive dysfunction (r=0.286, P=.042) and fluctuation of symptoms (r=0.280, P=.046) in the total sample. Subanalyses excluding patients taking antipsychotic drugs revealed that HVA CSF levels were higher in those patients with delusions, and furthermore, the dopamine metabolite remained positively correlated to delusion subscale of DRS.


CONCLUSIONS
Our results suggest that psychotic symptoms in delirious patients may be related to increased dopamine neurotransmission, as reflected by increased CSF HVA concentration, providing direct evidence to support the dopaminergic theory of psychosis.
Ramirez-Bermudez
Jesus
J
Department of Neuropsychiatry, National Institute of Neurology and Neurosurgery of Mexico, Insurgentes Sur 3877, Tlalpan 14269, Mexico City, Mexico.
Ruiz-Chow
Angel
A
Perez-Neri
Ivan
I
Soto-Hernandez
Jose Luis
JL
Flores-Hernandez
Ricardo
R
Nente
Francisco
F
Montes
Sergio
S
Rios
Camilo
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000134:cerebrospinal fluid / Q000175:diagnosis; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003693:Delirium / Q000134:cerebrospinal fluid* / Q000453:epidemiology / Q000503:physiopathology; D003702:Delusions / Q000134:cerebrospinal fluid / Q000175:diagnosis; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004298:Dopamine / Q000502:physiology; D005260:Female; D015658:HIV Infections / Q000134:cerebrospinal fluid / Q000175:diagnosis; D006212:Hallucinations / Q000134:cerebrospinal fluid / Q000175:diagnosis; D006719:Homovanillic Acid / Q000134:cerebrospinal fluid*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000134:cerebrospinal fluid* / Q000175:diagnosis / Q000453:epidemiology; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000134:cerebrospinal fluid* / Q000453:epidemiology / Q000503:physiopathology; D009435:Synaptic Transmission / Q000502:physiology
D004298:Dopamine; D006719:Homovanillic Acid