Stellate ganglion block shows promise in providing prolonged relief of chronic, extreme post-traumatic stress disorder (PTSD). A pilot 12-patient series by researchers from the Long Beach VA Healthcare System, while far from definitive, revealed that stellate ganglion block may also be effective in treating anxiety or depression.
“I became interested in this after seeing the case report by Eugene Lipov [Ann Clin Psychiatry 2008;20:227-228] that claimed that a patient had his PTSD symptoms completely relieved for a number of months by a single, right-sided stellate ganglion block,” said Michael T. Alkire, MD, a staff physician at Long Beach VA and professor of anesthesiology at the University of California, Irvine. “That report—and a subsequent study by Mulvaney [Pain Pract2010;10:349-365]—prompted me and my colleagues at the VA into action.”
Dr. Alkire and his colleagues enrolled 15 veterans into the study; each patient had extreme, chronic (>1 year) PTSD with hyperarousal symptoms. The subjects underwent a single, right-sided stellate ganglion block using 2% lidocaine 8 cc and 0.25% bupivacaine under fluoroscopic guidance, and then were followed for six months. All of the patients underwent a comprehensive battery of examinations, including the Clinician-Administered PTSD Scale (CAPS) score, Post-Traumatic Stress Disorder Symptom Scale–Self Report (PSS-SR), Beck Depression Inventory version 2, General Anxiety Scale, State-Trait Anxiety Inventory and Mee-Bunney Psychological Pain Assessment Scale. Assessments were conducted at baseline, and then at one week and one, three and six months post-block.
Figure. Mean Clinician-Administered PTSD Scale scores at baseline and following treatment in responders and nonresponders
CAPS, Clinician-administered PTSD Scale; PTSD, post-traumatic stress disorder; SGB, stellate ganglion block
Among the 12 patients who received the block, three primary responses were observed. “A few subjects were immediate nonresponders, and one of those three subjects actually felt worse because he was anxious about the lump in his neck,” Dr. Alkire said. “Most subjects [n=5] had moderate, generalized feelings of improvement. Interestingly, their scores got even better a week later, and continued to show improvement with time. And then there were four subjects that we would call ‘miracle cures.’ These patients essentially returned back to normal within a few minutes, before they even got off the fluoroscopy table.”
The block was effective in helping nine subjects (75%). For those who responded, the positive effects resulted in a significant reduction in scores of both the CAPS and PSS-SR at one week. “The positive effects lasted for a number of months and are still present in a few people as much as six months later,” Dr. Alkire noted here at the 2014 annual meeting of the American Society of Anesthesiologists (abstract A1046).
Anxiety, depression and psychological pain scores were significantly reduced by the block and also trended positively with time. “The improvement in depression ratings was so pronounced and so quick that it may rival electroconvulsive therapy,” Dr. Alkire explained. “So we propose that this block itself might be better for acute treatment of depressed patients.” Successfully treated subjects also demonstrated reduced arousal levels of respiratory sinus arrhythmia, heart rate variability and eye blink electromyographic responses.
Proposing a neurophysiologic mechanism of action for the dramatic response to the block is challenging, but Dr. Alkire offered a hypothesis. “I think based on our work investigating mechanisms of emotional memory that we are actually flipping the same switch that gets activated when someone is startled, but in this case, we are switching it in the opposite direction. So, we’re changing their parasympathetic/sympathetic tone to a more relaxed state almost instantly with the block.
“Our work, coupled with recent reports and ongoing studies, strongly suggests that a large, randomized controlled trial be undertaken to prove the effectiveness of this in a generalized population,” he said.
Session moderator Honorio T. Benzon, MD, saw value in performing a sham procedure as part of such a trial. “We published a case report of two patients in whom we did saline injection into the stellate ganglion as part of their diagnostic blocks. They developed Horner syndrome, increases in skin temperature of their ipsilateral hand, and partial pain relief,” said Dr. Benzon, professor of anesthesiology at Northwestern University’s Feinberg School of Medicine, in Chicago. “So, unless you do a placebo sham technique, you never really know what’s producing the effect you’re seeing.”