Prediction of panic response to a respiratory stimulant by reduced orbitofrontal cerebral blood flow in panic disorder.
OBJECTIVE
Lack of appropriate top-down governance by frontal cortical regions over a hypersensitive amygdala-centered fear neurocircuitry has been hypothesized to be central in the pathophysiology of panic disorder. The aim of this study was to examine regional cerebral blood flow changes in response to anxiety/panic provocation in subjects with panic disorder and healthy comparison subjects.


METHODS
Quantitative water method positron emission tomography was used to obtain brain images of five untreated subjects with panic disorder and five healthy comparison subjects before and during anxiogenic challenge with intravenous doxapram, an acute respiratory stimulant.


RESULTS
Baseline perfusion of the orbitofrontal cortex predicted panic attacks: lower perfusion was associated with heightened anxiety in response to doxapram challenge.


CONCLUSIONS
The orbitofrontal cortex may be important in the regulation of responding to fear and is a potential area of aberrant functioning in panic disorder.
Department of Psychiatry, Unit 41, Columbia University, 1051 Riverside Drive, New York, NY 10032, USA. jmk14@columbia.edu
Justine M
JM
Kent
Jeremy D
JD
Coplan
Osama
O
Mawlawi
Jose M
JM
Martinez
Susan T
ST
Browne
Mark
M
Slifstein
Diana
D
Martinez
Anissa
A
Abi-Dargham
Marc
M
Laruelle
Jack M
JM
Gorman
D000328:Adult; D000679:Amygdala / Q000502:physiology; D004315:Doxapram / Q000494:pharmacology*; D005239:Fear / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D010104:Oxygen Radioisotopes; D016584:Panic Disorder / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D049268:Positron-Emission Tomography; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D019141:Respiratory System Agents / Q000494:pharmacology*; D014867:Water
D010104:Oxygen Radioisotopes; D019141:Respiratory System Agents; D014867:Water; D004315:Doxapram