The Amygdala may be one of the key spots where both Stimulation and Blocking of the Sphenopalatine Ganglion act. It is important to remember the neural input, both positive and negative are are carried into the brain. This can change the balance of neurotransmitters in the brain and either cause or relieve not only pain but symptoms like anxiety and depression. Stimulation and Blocking of the Sphenopalatine Ganglion also transiently and reversibly changes the permeability of the Blood-Brain Barrier which has multiple implications for treatment of many disorders.
Understanding the Amazing effects of Self-Administered SphenoPalatine Ganglion (SPG) Blocks (SASPGB) in turning off pain may be enhanced by a new study. I have long felt that the effects of Sphenopalatine Ganglion Blocks was largely based on the Limbic System and turning off Sympathetic Overload and letting the Parasympathetic System dominate.
I explain to my patients that SPG blocks are a resetting action of the nociceptive input to the Trigeminal Nervous System and to the Limbic System. It acts in a manner similar to rebooting a computer by hitting Control /Alt/ Delete and lets the brain reboot in a healthier manner. When computer programmers set up large computer systems they often leave themselves a “Back Door” that they can access. The Sphenopalatine Ganglion can serve as that back door for the brain.
Dr. Fan Wang of Duke University has been researching brain regions in mice as targets for non-opioid pain interventions. His research was funded in part by NIH’s National Institute of Dental and Craniofacial Research (NIDCR) as part of NIH’s Helping to End Addiction Long-term (HEAL) Initiative. Dr Wang’s work was published on May 18, 2020, in Nature Neuroscience. The research revealed a small area of the brain in mice that can profoundly control the animals’ sense of pain.
The unexpected results showed that this brain center turns pain off, not on. It is located in the Amygdala an area generally associated with emotions and emotional impacts of pain. The Amygdala is sometimes wrongly considered only as an area of negative emotions.
As reported by the NIH https://www.nih.gov/news-events/nih-research-matters/scientists-find-new-pain-suppression-center-brain
“This search turned up a group of neurons in the central region of the brain’s amygdala. Because the amygdala is known to be activated by pain and plays a key role in processing fear, it’s an unexpected area for an anti-pain center.”
My CRANIO Journal article “Neuromuscular Dentistry and the Role of the Autonomic Nervous System: Sphenopalatine Ganglion Blocks and Neuromodulation. An International College of Cranio Mandibular Orthopedics (ICCMO) Position Paper” on use of SPG Blocks cited “The Amygdala is another important part of the limbic system that processes memory, especially memories associated with emotional responses, such as fear, pain, and anxiety . https://pubmed.ncbi.nlm.nih.gov/30973097/?from_single_result=sphenopalatine+ganglion+blocks+shapira
The approach utilized is in one way very similar to Sphenopalatine Ganglion (SPG or Pterygopalatine Ganglion) Blocks in that they work with “healthy and awake” mice. The joy in working with patients is they can express in no uncertain terms the almost relief they feel from Anxiety and Pain.
The work states they “manipulate the central amygdala neurons in healthy, awake mice.” The use of Sphenopalatine Ganglion Blocks is also utilized in healthy and awake human patients. Because they are very minimally invasive and extremely safe they do not evoke either pain or negative input to the brain or Limbic System. The responses to patients on the elimination of pain and anxiety can be expressed clearly by the patients.
“Activating these neurons suppressed the rodents’ responses to painful stimuli.” The use of Self-Administered SPG Blocks (SASPGB) also blocks or silences pain via the neurons in the Pterygopalatine Ganglion. This response is almost instantaneous in many patients. This is an example of Lisa who learned to Self-Administer SPG Blocks to treat and prevent chronic Migraine but was amazed when she experienced relief of Chronic Anxiety for the first time in her life! https://www.youtube.com/watch?v=WX4XE4Zk864&t=2s
There are many additional videos of patients who had almost instant relief of pain from self-administered SPG Blocks or by use of Neuromuscular Approach in TMD at https://www.youtube.com/channel/UCk9Bfz6pklC7_UluWFHzLrg/videos
The neurons also reduced nerve hypersensitivity called allodynia in the mice, where nonpainful inputs are felt or expressed as pain, which is also common in chronic neuropathic pain conditions such as trigeminal neuralgia, which affects the face and arises from nerve injury.
“This central amygdala node appears to be suppressing pain by sending inhibitory signals to widespread pain-processing areas of the brain,” Wang says. “Our work raises the possibility that tapping into the power of this internal analgesic system could be an effective alternative to opioids for relieving chronic pain.”
That “Internal analgesic system has been tapped into for over 100 years since Greenfield Sluder MD first described the use of Sphenopalatine Ganglion Blocks. I explain to patients that the brain acts like a computer and chronic pain issues like Allodynia are due to I/O or input / output errors. These input errors can be a combination of physical/ structural stressors, emotional stressors or biochemical stressors. Regardless of the underlying issues and causes Sphenopalatine are extremely effective in a large proportion of patients.
The Sphenopalatine Ganglion Block and specifically Self-Administered Sphenopalatine Ganglion Blocks done with continual capillary delivery of anesthetic to the nasal mucosa overlying the medial wall of the Pterygopalatine Fossa that holds both the Ganglion and the maxillary branch of the trigeminal Nerve and the maxillary artery.
When the scientists turned on the central amygdala neurons in mouse models of facial neuropathic pain, allodynia was markedly reduced.
Another recent article “A Central Amygdala-Ventrolateral Periaqueductal Gray Matter Pathway for Pain. in a Mouse Model of Depression-like Behavior” that concluded “These findings indicate that the central amygdala-ventrolateral periaqueductal gray pathway may mediate some aspects of pain symptoms under depression conditions.” This is again an action that can also be mediated thru Self-Administered SPG Blocks that often lead to a reduction of Anxiety and Depression as well as pain.
A more complete discussion of SPG Blocks can be found at: https://www.sphenopalatineganglionblocks.com/sphenopalatine-ganglion-block-treatment-chronic-episodic-chronic-headache-severe-headache-tension-headache-migraine-cluster-headache-trigeminal-autonomic-cephalgias/