RSNA: FDG uptake could help differentiate PTSD from mild TBI in veterans

CHICAGO—PET/CT has demonstrated promise for differentiating post-traumatic stress disorder (PTSD) from mild traumatic brain injury (mTBI) in military veterans, according to a study presented at the annual meeting of the Radiological Society of North America (RSNA).

The results of the study, which focused on the pituitary region of the brain, also suggested that many vets diagnosed with PTSD may in fact have hormonal irregularities stemming from pituitary gland damage from blast injury.

Lead author Thomas M. Malone, of the Department of Neurosurgery at Saint Louis University School of Medicine, noted that the pituitary gland is part of the HPA axis, which also includes the hypothalamus and adrenal glands and this system is suspected of playing a role in PTSD.

"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,” said Malone.

The current study featured a review of 159 brain 18F-FDG PET/CT exams in patients with both mTBI and PTSD, mTBI alone, and a group of matched controls. Results showed significantly lower FDG uptake in the hypothalamus in the mTBI-only group compared with normal controls, while uptake in the pituitary gland was significantly higher in the group of patients diagnosed with both mTBI and PTSD compared with the mTBI-only group.

Thomas and colleagues said the finding of higher FDG uptake in the pituitary glands of veterans with PTSD suggests that many diagnosed with the disorder may actually have hypopituitarism that is masking itself as PTSD. This may indicate that PET/CT could be an effective way to differentiate PTSD from mTBI and better understand the physical and biological differences between those with both conditions and those mTBI alone.