Functional neuroimaging evidence for hyperarousal in insomnia.
OBJECTIVE
The authors investigated the neurobiological basis of poor sleep and daytime fatigue in insomnia.


METHODS
[(18)F]Fluorodeoxyglucose positron emission tomography was used to assess regional cerebral glucose metabolism of seven patients with insomnia and 20 healthy subjects.


RESULTS
Compared with healthy subjects, patients with insomnia showed greater global cerebral glucose metabolism during sleep and while awake, a smaller decline in relative metabolism from waking to sleep states in wake-promoting regions, and reduced relative metabolism in the prefrontal cortex while awake.


CONCLUSIONS
Subjectively disturbed sleep in patients with insomnia is associated with greater brain metabolism. The inability to fall asleep may be related to a failure of arousal mechanisms to decline in activity from waking to sleep states. Further, daytime fatigue may reflect decreased activity in the prefrontal cortex resulting from inefficient sleep.
Nofzinger
Eric A
EA
Western Psychiatric Institute and Clinic, Sleep Neuroimaging Research Program, Department of Psychiatry, University of Pittsburgh School of Medicine, 3811 O'Hara St., Pittsburgh, PA 15213-2593, USA. nofzingerea@upmc.edu
Buysse
Daniel J
DJ
Germain
Anne
A
Price
Julie C
JC
Miewald
Jean M
JM
Kupfer
David J
DJ
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D001931:Brain Mapping; D004569:Electroencephalography; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D012890:Sleep / Q000502:physiology; D020921:Sleep Arousal Disorders / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism; D007319:Sleep Initiation and Maintenance Disorders / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000503:physiopathology; D014851:Wakefulness / Q000502:physiology
D019788:Fluorodeoxyglucose F18; D005947:Glucose