With a severe event there are real or perceived effects on the prefrontal cortex, which then causes changes to the amygdala and insular cortex. These changes are associated with fear and anxiety. Amygdala changes are noted on functional MRI. Soldiers with PTSD are known to have shrinkage of the insular cortex.
What can be done to help? Is their any new hope on the horizon?
Current treatments are not very effective. The most effective treatment currently is eye movement desensitization and reprocessing [EMDR] exposure plus cognitive restructuring. The mechanism of action is not understood. At least 10 sessions are required and the efficacy is still highly debated.
What is the science behind SGB treatment?
It is known that NGF [nerve growth factor] is produced after trauma leading to PTSD. Further, it is also known that NGF gets picked up from the brain and carried to the ganglia where activation of the terminals of the sympathetic nerves occurs leading to sprouting [new nerve growth] which then leads to more brain activation. The connections, demonstrated in the diagram below, were recently discovered to exist. Local anesthetic injection (SGB) leads to turning off this process by reduction or elimination of sprouting. We believe this then places the brain and rest of the system into the pre-trauma state.
ref4
(Stellate ganglion block may relieve hot flashes by interrupting the sympathetic nervous system. Medical Hypotheses, 2007. Volume 69, Issue 4, Pages 758 - 763 E. Lipov, S. Lipov, J. Joshi, V. Santucci, K. Slavin, S. Beck Vigue)
Neurobiological Explanation of the Effects of PTSD
