An integrative assessment of brain and body function 'at rest' in panic disorder: a combined quantitative EEG/autonomic function study.
We conducted a quantitative electroencephalographic (QEEG) and autonomic assessment of panic disorder (PD). The study samples comprised 52 individuals meeting DSM-IV criteria for PD (with or without agoraphobia) and 104 age-, gender-, and handedness-matched controls. EEG data were acquired from 16 scalp sites during resting eyes-open (REO) and eyes-closed (REC) conditions, and spectral power was assessed within 4 frequency bands: theta, alpha-1, alpha-2, and beta. The main findings were an overall reduction of spectral power in PD, compared to controls (Group main effect, p=.011), which was most apparent during REC (Group Condition interaction, p=.014), and within the alpha-1 frequency band (8-11 Hz; Group Band interaction, p=.014). Alpha-1 desynchronization occurs in response to increases in non-specific information processing, and aspects of attention such as alertness. Other findings were region-specific alterations of spectral power at frontal and temporal scalp sites, including a frontal alpha-1 asymmetry (R<L power) during REC in patients, but not controls. Findings for concomitantly-recorded autonomic measures included elevated heart rate, lower heart rate variability, and reduced rate of decrement of skin conductance level in patients, compared to controls. Finally, analyses examining the within-subjects relationship of central and peripheral function measures showed a differential pattern in patients and controls. Possible causes of these disturbances of brain and body function 'at rest', such as patients' ongoing automatic and strategic engagement with multiple disorder-related threat cues, including somatic variability and the testing environment, are discussed.
The Centre for Military and Veterans Health, School of Population Health and Clinical Practice, University of Adelaide, Adelaide, Australia. vikki.wise@adelaide.edu.au
Vikki
V
Wise
Alexander C
AC
McFarlane
C Richard
CR
Clark
Malcolm
M
Battersby
D000328:Adult; D000379:Agoraphobia / Q000209:etiology; D000513:Alpha Rhythm / Q000502:physiology; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D002490:Central Nervous System / Q000503:physiopathology; D004562:Electrocardiography; D004569:Electroencephalography / Q000379:methods; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000150:complications* / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D011601:Psychophysics; D012146:Rest