An fMRI motor activation paradigm demonstrates abnormalities of putamen activation in females with panic disorder.
BACKGROUND
The neurobiology of panic disorder is incompletely understood. The aim of this study was to determine if functional abnormalities of the putamen occur in panic disorder.


METHODS
Activation patterns of 12 female subjects with panic disorder were compared to 18 female healthy controls using functional MRI at 3 T. A motor activation paradigm was used to probe putamen function.


RESULTS
A complex motor activation paradigm for the non-dominant hand revealed decreased activation of the bilateral putamen among subjects with panic disorder.


CONCLUSIONS
The sample size was a relatively small cohort of non-depressed females. Further, some panic disorder subjects were taking medications and/or had comorbid conditions. However, second-level regression analyses did not reveal any correlations between medication use or comorbidity and activation patterns demonstrated by the non-dominant hand complex task. Finally, we used a post-hoc approach to determine the magnitude of global fMRI signal as a surrogate index of the global cerebral blood flow as a means of controlling for possible confounds from reduction of BOLD signal secondary to cerebral vasoconstriction resulting from possible hyperventilation among panic subjects. A more compelling approach would have been to record the respiratory data from subjects during scanning.


CONCLUSIONS
Our findings suggest that putamen dysfunction occurs in at least some cases of panic disorder. We also provide preliminary evidence that a complex motor task for the non-dominant hand is a useful probe of putamen function in this disorder.
Marchand
William R
WR
Department of Veterans Affairs VISN 19 MIRECC, Salt Lake City, Utah 84148, USA. william.marchand@va.gov
Lee
James N
JN
Healy
Lindsey
L
Thatcher
John W
JW
Rashkin
Esther
E
Starr
Jennifer
J
Hsu
Ed
E
D000328:Adult; D002560:Cerebrovascular Circulation; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D009043:Motor Activity; D009483:Neuropsychological Tests; D016584:Panic Disorder / Q000503:physiopathology*; D011597:Psychomotor Performance; D011699:Putamen / Q000503:physiopathology*; D013647:Task Performance and Analysis; D055815:Young Adult