Understanding and managing migraines and trigeminal autonomic cephalalgias: a multifaceted approach

Understanding and managing migraines and trigeminal autonomic cephalalgias: a multifaceted approach

Migraine and Trigeminal Autonomic Cephalalgias (TACs), including conditions like cluster headache, are characterized by intense, often debilitating, pain originating from the trigeminal nervous system. This intricate system transmits sensory information, including pain signals, from the face and head to the brain. Key to the pathophysiology of these disorders is the activation and sensitization of the trigeminal system, notably the release of Calcitonin Gene-Related Peptide (CGRP) from trigeminal nerve endings. This release contributes to both peripheral and central sensitization, perpetuating pain signals through interactions with adjacent neurons and glial cells in the central nervous system. 

The role of masticatory muscles and TMJ in trigeminal nociception

Beyond the classic understanding of trigeminal involvement, dysfunction in the temporomandibular joint (TMJ) and surrounding masticatory muscles plays a significant role in headache generation and exacerbation. This connection is explained by the close anatomical and neurological relationship between these structures and the trigeminal system. 

• Muscle Tension: Chronic tension in the masticatory muscles can radiate pain to the head, neck, and shoulders, contributing to headaches and potentially triggering migraines. Studies show that individuals with chronic migraines have a higher likelihood of reporting symptoms of TMJ disorder.
• Joint Dysfunction and Inflammation: Problems within the TMJ, such as disc displacement or inflammation, can irritate nearby nerves and blood vessels, further contributing to headache development.
• Referred Pain: Pain signals from the TMJ and masticatory muscles can be referred to other areas of the head, causing various headache syndromes. Myofascial pain and trigger points can also contribute to widespread pain.
• Trigeminal Convergence: Nociceptive inputs from both the TMJ/masticatory muscles and other areas, like meningeal tissues, converge in the trigeminal nucleus caudalis in the brainstem. This convergence can trigger or worsen migraine activity and contribute to central sensitization.
• Comorbidity: There's a strong association between TMDs and migraine, with the presence of one increasing the likelihood and severity of the other. 

Targeting trigeminal nociception: diverse approaches

Addressing trigeminal nociception is crucial for managing migraine and TACs, with various therapeutic avenues explored:

1. Medications:
   • Triptans: These medications primarily act as serotonin receptor agonists, aiming to inhibit CGRP release from trigeminal nerve endings.
   • CGRP-Targeted Therapies: Specifically designed to block CGRP activity, these therapies include:
     • Monoclonal Antibodies (mAbs): These antibodies target either the CGRP ligand or its receptor, preventing CGRP binding and activation. Examples include erenumab, fremanezumab, galcanezumab, and eptinezumab.
     • Gepants: Small-molecule CGRP receptor antagonists used for both acute and preventive migraine treatment. Examples include rimegepant and atogepant.
   • Other Preventative Medications: Include antidepressants, beta-blockers, and anticonvulsants that modulate trigeminal activity through different mechanisms.
2. Nerve Blocks:
   • Trigeminal Nerve Blocks: Local anesthetic injections into trigeminal nerve branches interrupt pain signal transmission.
   • Greater Occipital Nerve Blocks (GON Blocks): Injections of corticosteroids and anesthetic near the greater occipital nerve can provide relief, particularly in episodic cluster headaches.
   • Sphenopalatine Ganglion (SPG) Blocks: Local anesthetics target the SPG, a nerve bundle in the nasal cavity involved in pain signals and autonomic symptoms like tearing and nasal congestion. Methods of administration include intranasal catheters, viscous lidocaine with syringes, and nasal sprays/atomizers. SPG blocks can offer acute relief for various headache disorders.
3. Neurostimulation:
   • Non-invasive Vagus Nerve Stimulation (nVNS): Demonstrates effectiveness in both acute and preventive treatment for migraine and cluster headache. Studies suggest nVNS may inhibit trigeminal activation by enhancing pain modulation pathways involving GABAergic and serotonergic signaling.
   • Occipital Nerve Stimulation (ONS): Involves implanting electrodes near occipital nerves to modulate trigeminal nociceptive signals.
   • Sphenopalatine Ganglion (SPG) Stimulation: Involves stimulating the SPG, which has connections to the trigeminovascular system and has shown benefits in cluster headache.
4. Addressing TMJ Disorders: Treating TMDs can significantly reduce TMJ-related headaches and migraines. Approaches include:
   • Dental Interventions: This may involve custom oral appliances like splints or night guards to realign the jaw and reduce clenching and grinding. Orthodontic treatment or restorative dental work may also be necessary to correct bite misalignment.
   • Physical Therapy: Exercises to improve jaw function, reduce muscle tension, and alleviate strain in the head and neck can be beneficial. Manual therapy, ultrasound therapy, and electrical stimulation may also be used.
   • Medications: Over-the-counter or prescription anti-inflammatory drugs and muscle relaxants can help manage pain and muscle spasms. Botox injections may also be used in severe cases to relax jaw muscles.
   • Lifestyle Changes: Stress management techniques and avoiding habits that exacerbate jaw strain can also be helpful. 

Ultra-low frequency TENS (ULF-TENS) and the trigeminal and facial nerves

Ultra-Low Frequency Transcutaneous Electrical Nerve Stimulation (ULF-TENS) is a therapeutic technique utilized in managing orofacial pain and diagnosing and treating TMDs. ULF-TENS involves applying low-frequency electrical impulses to stimulate neural structures, including the trigeminal and facial nerves. This therapy aims to reduce inflammation, increase blood flow, release endorphins, and stimulate muscles to function aerobically. When masticatory muscles are in spasm, blood flow can be hindered, and ULF-TENS helps to promote muscle relaxation by increasing blood flow to the area. 

• Mechanism of Action: ULF-TENS stimulates the nerves that control the muscles associated with facial expression and jaw function. This stimulation is believed to activate central descending inhibitory pain pathways and trigger the release of endorphins, the body's natural painkillers, which in turn reduces pain and discomfort. According to the National Institutes of Health (NIH), ULF-TENS may modulate pain through central descending inhibitory pathways and affect trigeminal nerve fibers.
• Benefits: ULF-TENS can provide significant pain relief, reduce muscle tension and spasms, improve jaw function, and potentially reduce the frequency and severity of headaches and migraines associated with TMD. It is a non-invasive, drug-free approach with minimal side effects when used correctly.
• Application: Electrodes are typically placed over the trigeminal and facial nerves, stimulating them directly. 

Self-administration of sphenopalatine ganglion (SPG) blocks (SASPGBs)

Self-administering SPG blocks (SASPGBs) are emerging as a potential at-home option for treating acute migraines and other headaches.

Mechanism of action

SPG blocks work by targeting the SPG, a nerve bundle in the nasal cavity that transmits pain signals and autonomic symptoms associated with headaches. By delivering a local anesthetic like lidocaine to the SPG, pain pathways are interrupted, potentially providing acute pain relief. 

Administration methods

Several approaches are used for self-administering SPG blocks:

• Intranasal Catheters: Thin plastic catheters are inserted into the nostril to deliver the anesthetic. Commercially available devices include Sphenocath, Allevio, and TX360.
• Cotton-tipped catheters: These catheters offer a continual capillary feed of anesthetic to the mucosa overlying the pterygopalatine fossa, potentially enhancing efficacy due to prolonged exposure to the SPG. According to Think Better Life, this continuous flow allows patients to remain upright and functional while the anesthetic is delivered.
• Viscous Lidocaine with Syringe: Viscous lidocaine is instilled into the nostril using a syringe, with specific head positioning to help it reach the SPG region.
• Nasal Spray/Atomizer: This method uses a compounded anesthetic nasal spray or atomizer for potentially easier and more convenient administration.

Potential benefits

• Early Intervention: Blocks can be self-administered at the onset of a headache, potentially preventing or reducing its severity.
• Reduced Emergency Visits: Effective self-administration may reduce the need for hospital visits.
• Cost-Effectiveness: SASPGBs can be more affordable than emergency room visits or other costly treatments.
• Fewer Side Effects: SPG blocks, when administered properly, generally have limited systemic side effects compared to some medications.

Safety and risks

SASPGBs are generally considered safe, but certain safety and logistical considerations exist:

• Proper Technique and Training: Patients require thorough education and training to ensure correct administration and minimize risks.
• Adverse Effects: Potential adverse effects include nasal discomfort, bitter taste, throat numbness, and, rarely, nosebleeds or allergic reactions to the anesthetic.
• Nasal Bleeding or Infection: Improper technique could increase the risk of nasal bleeding or infection.
• Distinguishing Headache Subtypes: Patients need to be able to differentiate headache types and understand when self-administration is appropriate. 

Dr. Ira L. Shapira and the DNO®

Dr. Ira L. Shapira is a Chicago-area neuromuscular dentist with practices in Gurnee and Highland Park, IL. He specializes in treating migraines and TMJ disorders, holding credentials as a Diplomate of the American Board of Dental Sleep Medicine, a Diplomate of the American Academy of Pain Management, and a Fellow of the International College of Craniomandibular Orthopedics (ICCMO). He is also the Chair of the TMD Alliance. Dr. Shapira emphasizes a holistic approach to treating the root cause of the problem.  

One of the key tools in Dr. Shapira's practice is the DNO® Diagnostic Neuromuscular Orthotic. This custom oral appliance helps establish a healthy 3D jaw position, minimizing stress on the trigeminal nervous system and myofascial system. This reversible treatment is considered a crucial first step in his approach to addressing headaches, migraines, and TMJ disorders. Testimonials praise Dr. Shapira's expertise and the positive impact of the DNO®, with patients reporting significant reductions in headache frequency and severity, resolution of jaw locking and clicking, improved sleep, and a better quality of life. Some patients have worn permanent orthotics from Dr. Shapira for decades. 

Neuromuscular dentistry and the autonomic nervous system

Dr. Shapira has written on the link between neuromuscular dentistry and the autonomic nervous system. He has stated that addressing TMJ disorders and orofacial pain with neuromuscular dentistry can positively affect the autonomic nervous system. The central nervous system is influenced by nerve input from the body. The autonomic system includes the fight or flight response and affects heart rate, blood pressure, and muscle tone. Chronic stress can negatively impact this system, leading to biochemical changes in the brain. Correcting the neurological input is considered the preferred method for addressing these changes.

ICCMO

The International College of Cranio-Mandibular Orthopedics (ICCMO) is a society of health care professionals focused on occlusion, jaw function, and TMD. ICCMO members work to alleviate pain from TMDs and related head and neck pain, promoting research and education in neuromuscular dentistry. Dr. Shapira is an active member and has held leadership positions within the ICCMO. 

Conclusion

Managing migraine and TACs involves various strategies targeting trigeminal nociception, including medications, nerve blocks, neurostimulation, and addressing TMJ disorders. Self-administered SPG blocks, especially with cotton-tipped catheters, and ULF-TENS offer potential for at-home management of acute headaches and related pain. Dr. Ira L. Shapira's approach through neuromuscular dentistry and the DNO® addresses the connection between TMJ disorders and headaches, emphasizing the positive effects on the autonomic nervous system. Ongoing research continues to improve our understanding and treatment of headache disorders.

Important Note: Self-administration of SPG blocks should only be undertaken under the guidance and instruction of a qualified healthcare professional.  Dr Shapira is the Leading Practioner Teaching Self-Administration with Continual Capillary Feed via Cotton-Tipped Catheters