PET/CT Shows Pituitary Abnormalities in Veterans with PTSD

Images of the pituitary region of the brains of military veterans with post-traumatic stress disorder (PTSD), obtained by PET and CT, showed abnormalities, according to a new study presented this week at the annual meeting of the Radiological Society of North America (RSNA).

Researchers from the Saint Louis University School of Medicine in Missouri, sought to evaluate the use of 18F-fluorodeoxyglucose (18F-FDG) PET/CT in differentiating PTSD from mild traumatic brain injury (mTBI), based on metabolic activity in the pituitary and hypothalamic regions.                      

"The HPA axis is a complex system with a feedback loop, so that damage to any one of the three areas will affect the others," study lead author Thomas M. Malone, BA, said in a release. "It's suspected of playing an important role in PTSD, but there is limited neuroimaging research in the veteran population."

The researchers retrospectively reviewed 159 dedicated FDG PET/CT studies. The cases were divided into three groups: TBI, TBI and PTSD, and control. The patients in the TBI group were further stratified by severity, based on criteria from the Department of Defense and Veterans Affairs Consensus Definition of TBI. 

The findings showed that FDG uptake in the hypothalamus was significantly lower in the mTBI-only group compared with normal controls. FDG uptake in the pituitary gland was significantly higher in the mTBI and PTSD group compared with the MTBI-only group.

"This raises the possibility that some PTSD cases are actually hypopituitarism masking itself as PTSD," Malone explained in the release. "If that's the case, then we might be able to help those patients by screening for hormone irregularities and treating those irregularities on an individual basis."

"Currently, treatment for PTSD is typically limited to psychological therapy, antidepressants, and anxiety medications. Our findings reinforce the theory that there is something physically and biologically different in veterans who have MTBI and PTSD compared to those who just have MTBI."