Treatments
14. Peripheral Nerve blocks
Objective: Peripheral nerve blocks have multiple uses. In this office, we use them to treat: 1) neuralgic pain caused by injury, trauma, surgery, or disease that affects the peripheral nervous system, and 2) nerve pain caused by cancer.
Nerve blocks alter the way nerves transmit painful signals, and are a form of neuromodulation. Nerve blocks can be short- or longterm. Techniques include:
Local anesthetic peripheral nerve injection: This technique might not last as long as other peripheral nerve blocks, but it can help us diagnose the cause of your pain. Our goal is to expose a maximum area of the nerve to local anaesthetic.
The block usually addresses an area between the source of the nerve injury, and the connection to the spinal cord. When repeated several times, some patients notice a significant reduction in their neuralgic pain. This may be due to some form of neuromodulation to the dorsal horn on the spinal cord.
Local anesthetic peripheral neuroma injection: If a nerve becomes severed (say through trauma, surgery, or amputation), it tries to reconnect with the other severed end without success. The result is a benign nerve growth (neuroma), which resembles the shape of a broccoli flower.
Neuromas are sensitive to direct pressure, and fire electrically in a random pattern. The application of local anesthetic can reduce the resulting pain.
Radiofrequency techniques (RF): In this technique, we heat up the peripheral nerve in question through the application of a high frequency electrical signal.
Classic RF lesioning heats the nerve to 80 degrees Celsius for 60 - 90 seconds, causing nerve coagulation and disruption (rhizotomy). The result is permanent interruption of the pain signal (neuromodulation).
Pulsed radiofrequency (PRF) gently warms the nerve to 42 degrees Celsius for 10 -15 minutes. This technique keeps the nerve intact, while neuromodulating your pain.
Neurolytic peripheral nerve injection: This technique is usually reserved for patients with terminal conditions such as cancer, and who are close to the end of their life.
We apply nerve destructive substances such as phenol or absolute alcohol directly to the affected nerves. This neurolytic solution causes coagulation of the vasa nervorum (small vessels supplying the nerves). As a result, the nerve ceases functioning.
The effect can last 6-8 weeks, and needs to be timed carefully, as a chemical neuritis can develop which might be difficult to treat.
If the nerve is easily accessible, the block can usually be repeated.
The table below lists indications for different nerve blocks in the body.
Region |
Nerve |
Diagram |
Indications | |
Head |
Greater Occipital |
Occipital Neuralgia, Shingles | ||
Supratrochlear, Supraorbital, Infraorbital |
Facial Neuralgia, Shingles | |||
Gasserian Ganglion |
Trigeminal Neuralgia, Shingles, Facial Cancers | |||
Maxillary, Mandibular |
Trigeminal Neuralgia, Shingles, Facial Cancers | |||
Neck |
Superficial Cervical Plexus |
After Neck Surgery, Trauma | ||
Deep Cervical Plexus |
After Neck Surgery, Trauma | |||
Shoulder |
Suprascapular |
Chronic Shoulder Joint Arthritis | ||
Arm |
Brachial Plexus |
Interscalene Approach |
Brachial Plexus Injuries, Upper Limb Injuries, Pancoast Lung Cancer | |
Supraclavicular Approach |
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Infraclavicular Approach |
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Axillary Approach |
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Elbow |
Median, Radial |
Forearm and Hand Trauma, Neuralgia | ||
Ulnar |
Forearm and Hand Trauma, Neuralgia | |||
Wrist |
Median, Ulnar |
Hand Trauma, Neuralgia | ||
Dorsal Radial |
Dorsal Radial Neuralgia, Trauma | |||
Hand |
Digital |
Digital Neuralgia, Trauma | ||
Chest |
Intercostal |
Intercostal Neuralgia, After Thoracotomy | ||
Abdomen |
Intercostal |
Intercostal Neuralgia, After Nephrectomy | ||
Intra-operative Pain Relief For Abdominal Surgery | ||||
Pelvis |
Pudendal |
Pudendal Neuralgia, Pain relief for forceps delivery in labour | ||
Groin |
Iliohypogastric, Ilioinguinal |
After Hernia Surgery | ||
Thigh |
Sciatic |
Posterior Approach |
Sciatic Neuralgia, Buttock, Thigh and Leg Trauma | |
Anterior Approach |
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Lateral Approach |
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Femoral |
Femoral Neuralgia, Thigh Trauma | |||
Obturator |
Obturator Neuralgia, Pelvic Trauma | |||
Lateral Femoral Cutaneous |
Meralgia Paraesthetica | |||
Knee |
Common Peroneal, Posterior Tibial |
Tibial, Ankle and Foot Trauma | ||
Saphenous |
Saphenous Neuralgia, After Varicose Vein Surgery | |||
Ankle |
Saphenous, Sural, Posterior Tibial, Superficial Peroneal, Deep Peroneal |
Foot Neuralgias and Trauma | ||
Foot |
Digital |
Mortons Neuroma, Trauma |