Neuroanatomic correlates of CCK-4-induced panic attacks in healthy humans: a comparison of two time points.
BACKGROUND
Several functional imaging studies have demonstrated increases of brain activity in the temporofrontal, cingulate, and claustrum regions during a pharmacologically induced panic attack when scanning was done at a single point in time. However, no study has evaluated changes in brain activity at two time points during a panic attack. We hypothesized that in response to a single bolus injection of the panicogen cholecystokinin-4 (CCK-4) in healthy volunteers, changes in regional cerebral blood flow (rCBF) might be different if scanning were done at two different time points.


METHODS
To test this hypothesis, we conducted a single-blind study, using positron emission tomography (PET). To determine the time effect of panic attack on brain activity, we performed either early scan or late scan covering the first or the second minute after CCK-4 bolus injection, respectively. The PET images were analyzed by statistical parametric mapping (SPM) followed by region of interest (ROI) analysis.


RESULTS
The results showed significant differences between the early and the late scan. The early effects of CCK-4 are accompanied by increases in rCBF in the hypothalamic region, whereas the late scan showed an increase in rCBF in the claustrum-insular region. Reductions in rCBF were observed for both time groups in the medial frontal region. A separate scan for anticipatory anxiety demonstrated rCBF increases in the anterior cingulate region and decreases in the occipital regions.


CONCLUSIONS
These results may support the hypothesis that changes in rCBF as a function of time during CCK-4-induced panic might correspond to a neurocircuitry involved in panic attacks.
Javanmard
M
M
Royal Ottawa Hospital, Department of Psychiatry, University of Ottawa, Ontario, Canada.
Shlik
J
J
Kennedy
S H
SH
Vaccarino
F J
FJ
Houle
S
S
Bradwejn
J
J
D000328:Adult; D000704:Analysis of Variance; D001007:Anxiety / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology; D001479:Basal Ganglia / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects*; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006728:Hormones / Q000097:blood; D006801:Humans; D007031:Hypothalamus / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects; D008032:Limbic System / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010103:Oxygen Isotopes; D016584:Panic Disorder / Q000097:blood / Q000139:chemically induced / Q000503:physiopathology*; D016037:Single-Blind Method; D013758:Tetragastrin; D013997:Time Factors; D014055:Tomography, Emission-Computed
D006728:Hormones; D010103:Oxygen Isotopes; D013758:Tetragastrin