Radiosurgical Treatmement of Trigeminal Neuralgia: Pain Relief Correlates with Root Entry Zone Dose

✓ A multiinstitutional study was conducted to evaluate the technique, dose-selection parameters, and results of gamma knife stereotactic radiosurgery in the management of trigeminal neuralgia. Fifty patients at five centers underwent radiosurgery performed with a single 4-mm isocenter targeted at the nerve root entry zone. Thirty-two patients had undergone prior surgery, and the mean number of procedures that had been performed was 2.8 (range 1–7). The target dose of the radiosurgery used in the current study varied from 60 to 90 Gy. The median follow-up period after radiosurgery was 18 months (range 11–36 months). Twenty-nine patients (58%) responded with excellent control (pain free), 18 (36%) obtained good control (50%–90% relief), and three (6%) experienced treatment failure. The median time to pain relief was 1 month (range 1 day–6.7 months). Responses remained consistent for up to 3 years postradiosurgery in all cases except three (6%) in which the patients had pain recurrence at 5, 7, and 10 months. At 2 years, 54% of patients were pain free and 88% had 50% to 100% relief. A maximum radiosurgical dose of 70 Gy or greater was associated with a significantly greater chance of complete pain relief (72% vs. 9%, p = 0.0003). Three patients (6%) developed increased facial paresthesia after radiosurgery, which resolved totally in one case and improved in another. No patient developed other deficits or deafferentation pain. The proximal trigeminal nerve and root entry zone, which is well defined on magnetic resonance imaging, is an appropriate anatomical target for radiosurgery. Radiosurgery using the gamma unit is an additional effective surgical approach for the management of medically or surgically refractory trigeminal neuralgia. A longer-term follow-up review is warranted.

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Trigeminal interfascicular neurolysis (nerve combing) for refractory recurrent neuralgia in multiple sclerosis

Neurosurgical Focus: Video ◽

10.3171/2020.5.focvid203 ◽

2020 ◽

Vol 3 (2) ◽

pp. V3

Author(s):

Paolo Ferroli ◽

Ignazio G. Vetrano ◽

Francesco Acerbi ◽

Gabriella Raccuia ◽

Marco Schiariti ◽

...

Keyword(s):

Multiple Sclerosis ◽

Pain Relief ◽

Trigeminal Neuralgia ◽

Medical Therapy ◽

Myelin Sheath ◽

Neurovascular Conflict ◽

Entry Zone ◽

Link Type ◽

Root Entry Zone ◽

Good Pain Relief

In multiple sclerosis (MS) patients, trigeminal neuralgia (TN) represents a challenging syndrome to treat, often refractory to medical therapy and percutaneous techniques. Despite the frequent lack of a neurovascular conflict, the trigeminal nerve’s axons are often damaged, with the myelin sheath permanently degenerated, thus explaining the difficulty in treating TN in MS.The authors illustrate trigeminal interfascicular neurolysis (the combing technique) to control refractory recurrent TN in MS: the nerve is longitudinally divided along its fibers from the root entry zone, determining good pain relief.The video can be found here: https://youtu.be/o1XksPW5fMY

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Teflon bridge technique for endoscopic-assisted microvascular decompression of ectatic basilar artery and anterior inferior cerebellar artery for trigeminal neuralgia: operative video and technical nuances

Neurosurgical Focus: Video ◽

10.3171/2020.7.focvid2032 ◽

2020 ◽

Vol 3 (2) ◽

pp. V5

Author(s):

James K. Liu ◽

Asif Shafiq

Keyword(s):

Pain Relief ◽

Trigeminal Neuralgia ◽

Basilar Artery ◽

Microvascular Decompression ◽

Facial Pain ◽

Anterior Inferior Cerebellar Artery ◽

Safe Alternative ◽

Entry Zone ◽

Root Entry Zone ◽

Cerebellar Artery

In this illustrative operative video, the authors demonstrate a Teflon bridge technique to achieve safe transposition of a large, tortuous ectatic basilar artery (BA) and anterior inferior cerebellar artery (AICA) complex to decompress the root entry zone (REZ) of the trigeminal nerve in a 61-year-old woman with refractory trigeminal neuralgia via an endoscopic-assisted retractorless microvascular decompression. Postoperatively, the patient experienced immediate facial pain relief without requiring further medications. The Teflon bridge technique can be a safe alternative to sling techniques when working in narrow surgical corridors between delicate nerves and vessels. The operative technique and surgical nuances are demonstrated.The video can be found here: https://youtu.be/hIHX7EvZc1c

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Linear Accelerator Radiosurgery Using 90 Gray for Essential Trigeminal Neuralgia: Results and Dose Volume Histogram Analysis

Neurosurgery ◽

10.1227/01.neu.0000083550.03928.d8 ◽

2003 ◽

Vol 53 (4) ◽

pp. 823-830 ◽

Cited By ~ 58

Author(s):

Bryan W. Goss ◽

Leonardo Frighetto ◽

Antonio A.F. DeSalles ◽

Zachary Smith ◽

Timothy Solberg ◽

...

Keyword(s):

Pain Relief ◽

Trigeminal Neuralgia ◽

Nerve Root ◽

Linear Accelerator ◽

Treatment Plan ◽

Case Series ◽

Entry Zone ◽

Root Entry Zone ◽

Dose Volume ◽

Facial Numbness

Abstract OBJECTIVE To evaluate treatment of essential trigeminal neuralgia with 90 Gy delivered by a linear accelerator dedicated to radiosurgery. METHODS This is a retrospective case series of 25 patients with essential trigeminal neuralgia treated from March 1999 to March 2001. All were treated with 90 Gy by means of a 5-mm collimator directed to the nerve root entry zone. Patient follow-up (range, 8–52 mo; median, 18 mo) was completed by an uninvolved party. Dose volume histograms of the brainstem were developed for the 20, 30, and 50% isodose lines by means of radiosurgery planning software. RESULTS All patients obtained good to excellent pain relief with treatment. Nineteen (76%) of 25 patients achieved excellent pain relief (pain-free without medication). Six patients (24%) achieved good pain relief (50–90% reduction of pain with or without medication). Median time to pain relief was 2 months. Eight patients (32%) experienced relapse 4 to 13 months after treatment. Eight patients (32%) developed facial numbness, but none developed painful numbness. Mean brainstem volume within the 50% isodose line and occurrence of numbness was statistically significant (P = 0.03). There was no correlation between brainstem volume treated and outcome. CONCLUSION Dedicated linear accelerator-based stereotactic radiosurgery that uses a 5-mm collimator to deliver 90 Gy to the nerve root entry zone is a safe and effective method for the treatment of essential trigeminal neuralgia. Care should be taken to limit brainstem volume included in the 50% isodose line in the treatment plan to avoid facial numbness.

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Dorsal root entry zone lesions for the treatment of post-herpetic neuralgia

Journal of Neurosurgery ◽

10.3171/jns.1984.60.6.1258 ◽

1984 ◽

Vol 60 (6) ◽

pp. 1258-1262 ◽

Cited By ~ 43

Author(s):

Allan H. Friedman ◽

Blaine S. Nashold ◽

Janice Ovelmen-Levitt

Keyword(s):

Pain Relief ◽

Dorsal Root ◽

Post Herpetic Neuralgia ◽

Entry Zone ◽

Dorsal Root Entry Zone ◽

Content Type ◽

Root Entry Zone ◽

Adequate Pain Relief ◽

Good Pain Relief ◽

Transcutaneous Nerve Stimulation

✓ Post-herpetic pain was treated in 12 patients using dorsal root entry zone (DREZ) lesions. All patients had failed to receive adequate pain relief from conservative therapy consisting of transcutaneous nerve stimulation, carbamazepine, and/or amitriptyline. Dorsal root entry zone lesions were made to include the involved dermatomes plus one-half of the dermatomes above and below the painful areas. Eight patients reported good pain relief with follow-up periods ranging from 6 to 21 months. A ninth patient obtained satisfactory pain relief, but the superior 1 cm of the original painful area was not included in the distribution of the DREZ lesions. Patients whose lesions were performed using a thermally controlled lesion probe suffered no significant postoperative neurological deficit. Dorsal root entry zone lesions appeared to be a satisfactory treatment for post-herpetic neuralgia in patients who have failed to respond to more conservative modes of therapy.

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Pathophysiology of trigeminal neuralgia: new evidence from a trigeminal ganglion intraoperative microneurographic recording

Journal of Neurosurgery ◽

10.3171/jns.2004.101.5.0872 ◽

2004 ◽

Vol 101 (5) ◽

pp. 872-873 ◽

Cited By ~ 23

Author(s):

Kim J. Burchiel ◽

Thomas K. Baumann

Keyword(s):

Trigeminal Neuralgia ◽

Trigeminal Ganglion ◽

Physiological Mechanism ◽

Vascular Compression ◽

Entry Zone ◽

Content Type ◽

Root Entry Zone ◽

Trigeminal Ganglion Neurons ◽

Ganglion Neurons ◽

New Evidence

✓ The origin of trigeminal neuralgia (TN) appears to be vascular compression of the trigeminal nerve at the root entry zone; however, the physiological mechanism of this disorder remains uncertain. The authors obtained intraoperative microneurographic recordings from trigeminal ganglion neurons in a patient with TN immediately before percutaneous radiofrequency-induced gangliolysis. Their findings are consistent with the idea that the pain of TN is generated, at least in part, by an abnormal discharge within the peripheral nervous system.

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Neurovascular Compression at the Root Entry Zone Correlates with Trigeminal Neuralgia and Early Microvascular Decompression Outcome

World Neurosurgery ◽

10.1016/j.wneu.2016.08.040 ◽

2016 ◽

Vol 95 ◽

pp. 208-213 ◽

Cited By ~ 10

Author(s):

Akshitkumar M. Mistry ◽

Kurt J. Niesner ◽

Wendell B. Lake ◽

Jonathan A. Forbes ◽

Chevis N. Shannon ◽

...

Keyword(s):

Trigeminal Neuralgia ◽

Microvascular Decompression ◽

Neurovascular Compression ◽

Entry Zone ◽

Root Entry Zone

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Pain Relief After Dorsal Root Entry Zone Lesions

Advances in Stereotactic and Functional Neurosurgery 4 - Acta Neurochirurgica Supplementum ◽

10.1007/978-3-7091-8592-6_48 ◽

1980 ◽

pp. 383-389 ◽

Cited By ~ 10

Author(s):

B. S. Nashold ◽

R. H. Ostdahl

Keyword(s):

Pain Relief ◽

Dorsal Root ◽

Entry Zone ◽

Dorsal Root Entry Zone ◽

Root Entry Zone

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Analysis of morphological measurements of the trigeminal nerve in the linac stereotactic radiosurgery simulation targeting the root entry zone in trigeminal neuralgia

Neurocirugía ◽

10.1016/j.neucir.2018.10.001 ◽

2019 ◽

Vol 30 (3) ◽

pp. 105-114

Author(s):

Rafael Medélez-Borbonio ◽

Alexander Perdomo-Pantoja ◽

Alejandro Apolinar Serrano-Rubio ◽

Colson Tomberlin ◽

Rogelio Revuelta-Gutiérrez ◽

...

Keyword(s):

Trigeminal Neuralgia ◽

Stereotactic Radiosurgery ◽

Trigeminal Nerve ◽

Entry Zone ◽

Root Entry Zone

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Central Neuropathic Pain and Complex Regional Pain Syndrome Following Brachial Plexus Injury Treated Successfully With Dorsal Root Entry Zone Lesioning

Neurosurgery ◽

10.1093/neuros/nyz310_703 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Erin McCormack ◽

Mansour H Mathkour ◽

Lora Wallis Kahn ◽

Reda Tolba ◽

Maged Guirguis ◽

...

Keyword(s):

Neuropathic Pain ◽

Pain Relief ◽

Brachial Plexus ◽

Dorsal Root ◽

Brachial Plexus Injury ◽

Pain Syndrome ◽

Entry Zone ◽

Dorsal Root Entry Zone ◽

Central Neuropathic Pain ◽

Root Entry Zone

Abstract INTRODUCTION Central neuropathic pain (CNP) and complex regional pain syndrome (CRPS) present as chronic, unrelenting, and disabling pain resulting from central and peripheral nervous system injuries. For patients who have failed conservative management, dorsal root entry zone (DREZ) lesioning may serve as an alternative for the management of intractable pain. METHODS A 36-yr-old male presented with complete right brachial plexus injury and avulsion of nerve roots following a motorcycle accident. He developed disabling type I CRPS of the right upper extremity. After failing medical therapy, he underwent a trial of conventional SCS using 2 percutaneous leads in the upper cervical spine but did not get topographical coverage. He underwent a second SCS trial with the placement of a paddle lead using burst therapy, but his initial partial pain relief subsided after 3 d. Subsequently, he underwent SCS removal, C2 to T1 right DREZ lesioning, and C4 to T1 laminoplasty. The patient gained a significant pain relief and became more functional. Five months postoperatively, he experienced an improvement in his pain and narcotic consumption. RESULTS Using an insulated neurotomy electrode, 2-mm-deep lesions were made at 75°C for 15 s. A total of 83 lesions were made from T2 to C3. Each lesion was spaced 1 mm apart. The impedance was less than 1000 ohms, which was consistent within an area of injury. Somatosensory and motor-evoked potentials were at baseline during the case without significant changes. CONCLUSION When SCS fails, lesioning of the dorsal root entry zone is a useful tool in the armamentarium for the management of refractory brachial plexus neuropathic pain.

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