Increased GABA levels in medial prefrontal cortex of young adults with narcolepsy.
OBJECTIVE
To explore absolute concentrations of brain metabolites including gamma amino-butyric acid (GABA) in the medial prefrontal cortex and basal ganglia of young adults with narcolepsy.


METHODS
Proton magnetic resonance (MR) spectroscopy centered on the medial prefrontal cortex and the basal ganglia was acquired. The absolute concentrations of brain metabolites including GABA and glutamate were assessed and compared between narcoleptic patients and healthy comparison subjects.


METHODS
Sleep and Chronobiology Center at Seoul National University Hospital; A high strength 3.0 Tesla MR scanner in the Department of Radiology at Seoul National University Hospital.


METHODS
Seventeen young adults with a sole diagnosis of HLA DQB1 0602 positive narcolepsy with cataplexy (25.1 +/- 4.6 years old) and 17 healthy comparison subjects (26.8 +/- 4.8 years old).


METHODS
N/A.


RESULTS
Relative to comparison subjects, narcoleptic patients had higher GABA concentration in the medial prefrontal cortex (t = 4.10, P <0.001). Narcoleptic patients with nocturnal sleep disturbance had higher GABA concentration in the medial prefrontal cortex than those without nocturnal sleep disturbance (t = 2.45, P = 0.03), but had lower GABA concentration than comparison subjects (t = 2.30, P = 0.03).


CONCLUSIONS
The current study reports that young adults with narcolepsy had a higher GABA concentration in the medial prefrontal cortex, which was more prominent in patients without nocturnal sleep disturbance. Our findings suggest that the medial prefrontal GABA level may be increased in narcolepsy, and the increased medial prefrontal GABA might be a compensatory mechanism to reduce nocturnal sleep disturbances in narcolepsy.
Kim
Seog Ju
SJ
Department of Psychiatry, Gachon University of Medicine and Science, Incheon, South Korea.
Lyoo
In Kyoon
IK
Lee
Yujin S
YS
Sung
Young Hoon
YH
Kim
Hengjun J
HJ
Kim
Jihyun H
JH
Kim
Kye Hyun
KH
Jeong
Do-Un
DU
D000328:Adult; D001479:Basal Ganglia / Q000503:physiopathology; D002385:Cataplexy / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D005260:Female; D005838:Genotype; D018698:Glutamic Acid / Q000378:metabolism; D006683:HLA-DQ Antigens / Q000235:genetics; D059866:HLA-DQ beta-Chains; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics; D009290:Narcolepsy / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012016:Reference Values; D020178:Sleep Disorders, Circadian Rhythm / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D008562:Membrane Glycoproteins; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid