PainExam Show Notes: Mandibular Division of the Trigeminal Nerve Block with Dr. David Rosenblum Introduction

• Host: Dr. David Rosenblum
• Topic: Mandibular Division of the Trigeminal Nerve Block for Cancer Pain Management
• Techniques: Ultrasound and Fluoroscopic Guidance

Overview

• Purpose: Alleviate chronic facial pain, specifically in cancer patients suffering from trigeminal neuralgia or other related conditions.
• Focus: Detailed discussion on the anatomy, clinical presentation, and procedural techniques for effective nerve block.

Anatomy of the Mandibular Nerve

• Origin: Mandibular nerve is a branch of the trigeminal nerve (cranial nerve V).
• Pathway: Exits the middle cranial fossa through the foramen ovale and descends between the lateral and medial pterygoid muscles.
• Sensory Innervation:
  • Anterior two-thirds of the tongue
  • Teeth and mucosa of the mandible
  • Skin of the chin and lower lip
  • Skin over the mandible (excluding the mandibular angle)
  • Tragus and anterior part of the ear
  • Posterior part of the temporalis muscle up to the scalp

Ultrasound-Guided Technique

1. Patient Positioning:
   • Patient lies on their side with the affected side facing upward.
2. Transducer Selection:
   • Curvilinear transducer preferred for deeper structures.
3. Transducer Placement:
   • Place distal and parallel to the zygomatic arch to bridge the coronoid and condylar processes.
4. Anatomical Landmarks:
   • Identify the lateral pterygoid muscle and plate.
   • Use power Doppler to locate the sphenoid palatine artery.
5. Needle Trajectory:
   • Introduce the needle using an out-of-plane approach to target the pterygopalatine fossa (anterior to the lateral pterygoid plate).
   • For the mandibular nerve block, target the area posterior to the lateral pterygoid plate between the medial and lateral pterygoid muscles.
6. Electrostimulation (Optional):
   • Utilize a 22G, 10 cm insulated short beveled needle connected to a peripheral nerve simulator.
   • Position confirmed by motor response from the temporalis and masseter muscles.

Fluoroscopic-Guided Technique

1. Patient Positioning:
   • Similar to ultrasound guidance, patient lies on their side with the affected side facing upward.
2. C-arm Positioning:
   • Position the C-arm to visualize the foramen ovale.
3. Needle Insertion:
   • Insert the needle under fluoroscopic guidance towards the foramen ovale.
4. Contrast Injection:
   • Confirm needle placement with contrast injection.
5. Anesthetic Administration:
   • Administer local anesthetic and/or neurolytic agents.

Clinical Symptoms and Diagnosis

• Symptoms:
  • Unilateral sharp, stabbing, or burning pain in the mandibular nerve distribution.
  • Pain triggered by activities such as eating, talking, washing the face, or cleaning the teeth.
• Diagnostic Imaging:
  • MRI or CT scans to identify causes like vascular compression, mass lesions, or fractures.

Complications and Considerations

• Potential Complications:
  • Bleeding, hematoma, infection, and hypersensitivity reaction to the injectate.
  • Serious complications from neurolytic agents like permanent sensory deficit and tissue necrosis.
• Alternative Treatments:
  • PNS? Radiofrequency or cryoablation for recalcitrant cases.

Conclusion

• Efficacy: Ultrasound and fluoroscopic guidance provide precise targeting of the affected nerves, minimizing collateral damage.
• Safety: Routine use of power Doppler imaging to avoid injury to surrounding vessels.
• Recommendation: Consider these techniques for patients unresponsive to oral medications or unsuitable for surgery.

These show notes provide a comprehensive overview of the discussion, highlighting key points on the anatomy, technique, and clinical considerations for mandibular nerve blocks in cancer patients.

Other Announcements from NRAP Academy:

• PainExam App is ready for iphone
•  
  •  Pain Management Board Prep migrated to NRAPpain.org
• AnesthesiaExam Board Prep migrated to NRAPpain.org
• PMRExam Board Prep migrated to NRAPpain.org

  Live Workshop Calendar

 

 

  Ultrasound Interventional Pain Course Registration    For Anesthesia Board Prep Click Here!

References

Nicholas A Telischak, Jeremy J Heit, Lucas W Campos, Omar A Choudhri, Huy M Do, Xiang Qian, Fluoroscopic C-Arm and CT-Guided Selective Radiofrequency Ablation for Trigeminal and Glossopharyngeal Facial Pain Syndromes, Pain Medicine, Volume 19, Issue 1, January 2018, Pages 130–141, https://doi.org/10.1093/pm/pnx088

Allam, Abdallah El-Sayed, et al. "Ultrasound‐Guided Intervention for Treatment of Trigeminal Neuralgia: An Updated Review of Anatomy and Techniques." Pain Research and Management 2018.1 (2018): 5480728.

isclaimer

Disclaimer: This Podcast, website and any content from NRAP Academy (NRAPpain.org) otherwise known as Qbazaar.com, LLC is  for general informational purposes only and does not constitute the practice of medicine, nursing or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this podcast or materials linked from this podcast is at the user’s own risk. Professionals should conduct their own fact finding, research, and due diligence to come to their own conclusions for treating patients. The content of this podcast is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard or delay in obtaining medical advice for any medical condition they may have and should seek the assistance of their health care professionals for any such conditions.