Shoulder tip pain is a type of referred pain where the shoulder meets the arm. This study was a clinical report of two patients who experienced pain relief after a thoracic surgery. It was presumed that the pain in these cases was referred from diagphragm irritation.
Shoulder tip pain is also known to occur in ectopic pregnancy.
While there are many causes of shoulder pain shoulder tip pain appears to be related to internal organs. The connection to the Spenopalatine Ganglion (SPG) is unknown but the connection is likely due to the sympathetic and parasympathetic nerve fibers that pass thru the SPG.
One cannot rule out central connections in the CNS and the Trigeminal Nervous system as the mechanism of pain relief after SPG Block.
It is also possible that the control of the blood flow to the meninges in the anterior 2/3 of the brain is the route of pain reduction with an SPG Block.
The trigeminal nervous system has an enormous input into the hypothalamus, Amygdala and entire limbic system. It is also possible that this pain relief is related directly to this emotional center.
Stellate Ganglion Blocks given for CRPS or Complex Regional Pain Syndrome have had secondary effects of curing PTSD or Post Traumatic Stress Disorder. It has been hypothesized that this is also a limbic system event. PHN or Post Herpetic Nerualgia has also been treated with Stellate Ganglion Blocks. This opens the possibility that Self-Administered SPG Blocks could be helpful for pain relief. This would especially be true in areas that are innervated by the Trigeminal Nervous System.
It is known the the Stellate Ganglion is at the bottom of the Sympathetic Cervical Chain and that fibers from the Stellate Ganglion and the entire chain travel up the chain to the Superior Cervical Ganglion and on to Sphenopalatine Ganglion.
This is a subject that is very relevant in the field of pain management and hopefully there will be additional studiers evaluating this effect.
While it is not seen in the literature this author has heard anecdotal stories on menstrual cramping and pain being relieved with SPG Blocks. These patients were typically utilizing Self-Administered SPG Blocks or SASPGB.
ClinicalTrials.gov reported a trial “Sphenopalatine Ganglion Block to Prevent Shoulder Pain After Laprasopic Bariatric Surgery” Shoulder tip pain has been reported after this type of laprascopic surgery however none of the participants in the study reported shoulder tip pain before the completion of the trial.
A recent article in A A Pract 2018 Aug 15;11(4):90-92.
Sphenopalatine Ganglion Block to Treat Shoulder Tip Pain After Thoracic Surgery: Report of 2 Cases
Gilbert J Grant 1, Ghislaine C Echevarria 1, Jerome Lax 1, Harvey I Pass 2, Michael L Oshinsky 2
PMID: 29634542 DOI: 10.1213/XAA.0000000000000746
Shoulder tip pain may occur after thoracic surgical procedures. The pain is caused by diaphragmatic irritation and is referred to the shoulder. Shoulder tip pain is often resistant to treatment with conventional analgesics. The sphenopalatine ganglion block has been described to manage many painful conditions. We report here the first use of this block to treat shoulder tip pain in 2 thoracic surgical patients. In both patients, the block produced rapid and sustained relief of the shoulder tip pain. We suggest that sphenopalatine ganglion block be considered to treat postoperative shoulder tip pain after thoracic surgical procedures.
Another excellent article on Autonomic Ganglion Blocks (abstract)
Ganglion blocks as a treatment of pain: current perspectives
The inputs from sympathetic ganglia have been known to be involved in the pathophysiology of various painful conditions such as complex regional pain syndrome, cancer pain of different origin, and coccygodynia. Sympathetic ganglia blocks are used to relieve patients who suffer from these conditions for over a century. Many numbers of local anesthetics such as bupivacaine or neurolytic agents such as alcohol can be chosen for a successful block. The agent is selected according to its duration of effect and the purpose of the injection. Most commonly used sympathetic blocks are stellate ganglion block, lumbar sympathetic block, celiac plexus block, superior hypogastric block, and ganglion Impar block. In this review, indications, methods, effectiveness, and complications of these blocks are discussed based on the data from the current literature.
There is a reference of a case report of PHN or Post Herpetic Neuralgia being treated by SPG Blocks. Transnasal Sphenopalatine Ganglion Block for Post Herpetic Ophthalmic Neuralgia: A Case Report.
Abstract Post herpetic ophthalmic neuralgia can often be a frustrating condition for both patients and physicians due to its medical treatment resistance. In this case report, we demonstrate the effectiveness of the transnasal sphenopalatine ganglion block in treating severe, debilitating post herpetic ophthalmic neuralgia. We utilized the transnasal technique with a cotton tipped applicator soaked in 4% lidocaine. This technique is advantageous in that it is noninvasive, well tolerated, technically simple, and easy to repeat if necessary. We propose an increased consideration of the transnasal sphenopalatine ganglion block for the treatment of post herpetic ophthalmic neuralgia. Link to entire article: http://medcraveonline.com/JACCOA/JACCOA-08-00323.pdf