ReviewSympathetic system modulation to treat post-traumatic stress disorder (PTSD): A review of clinical evidence and neurobiology
Introduction
Post-traumatic stress disorder (PTSD) is a chronic anxiety disorder caused by seeing or experiencing traumatic events. The symptoms of PTSD include re-experiencing the event through flashbacks or nightmares, avoidance of stimuli which remind the victim of the traumatic event, and increased arousal, such as anxiety, anger or hypervigilance. A formal diagnosis of PTSD requires these symptoms to persist for at least a month and to cause significant disruption in one's personal and/or professional life. The person with PTSD has clinically significant distress and/or functional impairment.
The potential for experiencing stress and trauma is a part of the human condition. Trauma may be physical or psychological, or both, and is caused by a variety of circumstances—domestic violence, terrorism, war. Its incidence is very likely to increase due to a multitude of factors. Military populations in particular are likely to be affected due to the ongoing, large-scale military operations in the past decade. The rise in international terrorism, combined with natural disasters such as tsunami, earthquakes, hurricanes and others, will likely exacerbate the increased prevalence of PTSD.
In addition to the psychiatric toll of PTSD, the financial burden of caring for civilian and military patients with this disorder is significant. In veteran populations affected by the Gulf Wars, financial impact is projected to be overwhelming–the eventual cost of covering lifetime benefits for veterans (medical, disability benefits, and social security) may reach $700 billion or more (Stiglitz and Bilmes, 2008). This is approximately the total overall cost of the first five years of war. The human cost of PTSD as well as financial are extreme, pointing to the pressing need for finding an effective, available treatment.
Section snippets
Historical perspective of PTSD
The earliest description of PTSD in the modern era was from the Civil War (1861–1865): “irritable heart” or “soldiers' heart” (Da Costa, 1871). According to a paper published in 1876 by Mendez DaCosta, MD, Civil War combat veterans with “soldiers' heart” had startle responses, hyper-vigilance, and heart arrhythmia, thus the first modern description of PTSD had a physiologic description. Further designations for PTSD followed. Current term PTSD was introduced in the 1980s in the United States
Pharmaceuticals plus cognitive behavioral therapy (CBT)
Conventional PTSD treatment comprises two complementary strategies: (1) Medication to reduce anxiety and/or arousal (the selective serotonin reuptake inhibitors or SSRIs); (2) Cognitive behavioral therapy (CBT). Primarily indicated to address mood disorders, the SSRIs increase the amount of serotonin circulating in the brain but they have been shown to be helpful in mediating PTSD symptoms. However, side effects include sexual dysfunction (Balon, 2006), somnolence (Giner et al., 2005), and an
Proposed mechanism of action for invasive SNS procedures
The best understood member of the neurotropic family, nerve growth factor (NGF) regulates a variety of signaling events such as cell differentiation and survival, growth cessation, and apoptosis (death) of neurons (Snider, 1994). The body responds to chronic stress by increasing NGF levels (Smith, 1996) and NGF is also known to be elevated immediately prior to soldiers' first parachute jump (Alleva et al., 1996) thus demonstrating a connection between NGF, stress and possibly PTSD. Further
Conclusion
In summary, the sympathetic nervous system appears to mediate PTSD. Encouraging reports have been published recently regarding improvements in PTSD symptoms following direct SNS modulation. The double-blind, placebo-controlled rat studies which demonstrate significant improvement in PTSD models speak to the efficacy of those approaches as do the early reports of use of SGB in humans for treatment of PTSD. It is our sincere hope that in the near future, invasive sympathetic modulating techniques
Role of funding source
This was a non-funded report.
Conflict of interest
There are no conflicts of interest.
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