Increased glutamate/glutamine compounds in the brains of patients with fibromyalgia: a magnetic resonance spectroscopy study.
OBJECTIVE
Fibromyalgia (FM) has been defined as a systemic disorder that is clinically characterized by pain, cognitive deficit, and the presence of associated psychopathology, all of which are suggestive of a primary brain dysfunction. This study was undertaken to identify the nature of this cerebral dysfunction by assessing the brain metabolite patterns in patients with FM through magnetic resonance spectroscopy (MRS) techniques.


METHODS
A cohort of 28 female patients with FM and a control group of 24 healthy women of the same age were studied. MRS techniques were used to study brain metabolites in the amygdala, thalami, and prefrontal cortex of these women.


RESULTS
In comparison with healthy controls, patients with FM showed higher levels of glutamate/glutamine (Glx) compounds (mean +/- SD 11.9 +/- 1.6 arbitrary units [AU] versus 13.4 +/- 1.7 AU in controls and patients, respectively; t = 2.517, 35 df, corrected P = 0.03) and a higher Glx:creatine ratio (mean +/- SD 2.1 +/- 0.4 versus 2.4 +/- 1.4, respectively; t = 2.373, 35 df, corrected P = 0.04) in the right amygdala. In FM patients with increased levels of pain intensity, greater fatigue, and more symptoms of depression, inositol levels in the right amygdala and right thalamus were significantly higher.


CONCLUSIONS
The distinctive metabolic features found in the right amygdala of patients with FM suggest the possible existence of a neural dysfunction in emotional processing. The results appear to extend previous findings regarding the dysfunction in pain processing observed in patients with FM.
Valdés
Manuel
M
Institut d'Investigacions Biomèdiques August Pi i Sunyer and Hospital Clínic of Barcelona, Barcelona, Spain.
Collado
Antonio
A
Bargalló
Nuria
N
Vázquez
Mireia
M
Rami
Lorena
L
Gómez
Emili
E
Salamero
Manel
M
D001007:Anxiety / Q000150:complications / Q000175:diagnosis; D001921:Brain / Q000378:metabolism*; D001931:Brain Mapping; D016009:Chi-Square Distribution; D003401:Creatine / Q000378:metabolism; D003863:Depression / Q000150:complications / Q000175:diagnosis; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D011569:Psychiatric Status Rating Scales
D005973:Glutamine; D018698:Glutamic Acid; D003401:Creatine