Varying length of central myelin along the trigeminal nerve might contribute to trigeminal neuralgia

2019 ◽  
Vol 32 (4) ◽  
pp. 541-545 ◽  
Author(s):  
Kei Nomura ◽  
Hiroshi Ryu ◽  
Koji Ohno ◽  
Kohji Sato
Keyword(s):  
Trigeminal Neuralgia ◽  
Trigeminal Nerve ◽  
Central Myelin ◽  
Varying Length

Microanatomy of the Central Myelin-Peripheral Myelin Transition Zone of the Trigeminal Nerve

Neurosurgery ◽  
2006 ◽  
Vol 59 (2) ◽  
pp. 354-359 ◽  
Author(s):  
Selçuk Peker ◽  
Özlem Kurtkaya ◽  
İbrahim Üzün ◽  
M Necmettin Pamir
Keyword(s):  
Trigeminal Neuralgia ◽  
Trigeminal Nerve ◽  
Transitional Zone ◽  
Vascular Compression ◽  
Lateral Aspect ◽  
Entry Zone ◽  
Root Entry Zone ◽  
Central Myelin ◽  
Trigeminal Nerves ◽  
Vascular Decompression

Abstract OBJECTIVE: The aim of this study was to evaluate the microanatomy of the central myelin-peripheral myelin transitional zone (TZ) in trigeminal nerves from cadavers. METHODS: One hundred trigeminal nerves from 50 cadaver heads were examined. The cisternal portion of the nerve (from the pons to Meckel's cave) was measured. Horizontal sections were stained and photographed. The photomicrographs were used to measure the extent of central myelin on the medial and lateral aspects of the nerve and to classify TZ shapes. RESULTS: The cisternal portions of the specimens ranged from 8 to 15 mm long (mean, 12.3 mm; median, 11.9 mm). The data from the photomicrographs revealed that the extent of central myelin (distance from pons to TZ) on the medial aspect of the nerve (range, 0.1–2.5 mm; mean, 1.13 mm; median, 1 mm) was shorter than that on the lateral aspect (range, 0.17–6.75 mm; mean, 2.47 mm; median, 2.12 mm). CONCLUSION: The data definitively prove that the root entry zone (REZ, nerve-pons junction) and TZ of the trigeminal nerve are distinct sites and that these terms should never be used interchangeably. The measurements showed that the central myelin occupies only the initial one-fourth of the trigeminal nerve length. If trigeminal neuralgia is caused exclusively by vascular compression of the central myelin, the problem vessel would always have to be located in this region. However, it is well known that pain from trigeminal neuralgia can resolve after vascular decompression at more distal sites. This suggests that the effects of surgical decompression are caused by another mechanism.

Temporal disconnection between pain relief and trigeminal nerve microstructural changes after Gamma Knife radiosurgery for trigeminal neuralgia

2020 ◽  
Vol 133 (3) ◽  
pp. 727-735
Author(s):  
Peter Shih-Ping Hung ◽  
Sarasa Tohyama ◽  
Jia Y. Zhang ◽  
Mojgan Hodaie
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Pain Intensity ◽  
Gamma Knife ◽  
Trigeminal Nerve ◽  
Diffusion Tensor ◽  
Gamma Knife Radiosurgery ◽  
Time Points ◽  
Microstructural Effect

OBJECTIVEGamma Knife radiosurgery (GKRS) is a noninvasive surgical treatment option for patients with medically refractive classic trigeminal neuralgia (TN). The long-term microstructural consequences of radiosurgery and their association with pain relief remain unclear. To better understand this topic, the authors used diffusion tensor imaging (DTI) to characterize the effects of GKRS on trigeminal nerve microstructure over multiple posttreatment time points.METHODSNinety-two sets of 3-T anatomical and diffusion-weighted MR images from 55 patients with TN treated by GKRS were divided within 6-, 12-, and 24-month posttreatment time points into responder and nonresponder subgroups (≥ 75% and < 75% reduction in posttreatment pain intensity, respectively). Within each subgroup, posttreatment pain intensity was then assessed against pretreatment levels and followed by DTI metric analyses, contrasting treated and contralateral control nerves to identify specific biomarkers of successful pain relief.RESULTSGKRS resulted in successful pain relief that was accompanied by asynchronous reductions in fractional anisotropy (FA), which maximized 24 months after treatment. While GKRS responders demonstrated significantly reduced FA within the radiosurgery target 12 and 24 months posttreatment (p < 0.05 and p < 0.01, respectively), nonresponders had statistically indistinguishable DTI metrics between nerve types at each time point.CONCLUSIONSUltimately, this study serves as the first step toward an improved understanding of the long-term microstructural effect of radiosurgery on TN. Given that FA reductions remained specific to responders and were absent in nonresponders up to 24 months posttreatment, FA changes have the potential of serving as temporally consistent biomarkers of optimal pain relief following radiosurgical treatment for classic TN.

MRI features of responsible contacts in vascular compressive trigeminal neuralgia and prediction modeling

2021 ◽  
pp. 028418512098397
Author(s):  
Yufei Zhao ◽  
Jianhua Chen ◽  
Rifeng Jiang ◽  
Xue Xu ◽  
Lin Lin ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Predictive Model ◽  
Trigeminal Nerve ◽  
Roc Curve ◽  
Neurovascular Compression ◽  
Diagnostic Efficiency ◽  
Mri Features ◽  
Vascular Origin ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Characteristics

Background Multiple neurovascular contacts in patients with vascular compressive trigeminal neuralgia often challenge the diagnosis of responsible contacts. Purpose To analyze the magnetic resonance imaging (MRI) features of responsible contacts and establish a predictive model to accurately pinpoint the responsible contacts. Material and Methods Sixty-seven patients with unilateral trigeminal neuralgia were enrolled. A total of 153 definite contacts (45 responsible, 108 non-responsible) were analyzed for their MRI characteristics, including neurovascular compression (NVC) grading, distance from pons to contact (Dpons-contact), vascular origin of compressing vessels, diameter of vessel (Dvessel) and trigeminal nerve (Dtrigeminal nerve) at contact. The MRI characteristics of the responsible and non-responsible contacts were compared, and their diagnostic efficiencies were further evaluated using a receiver operating characteristic (ROC) curve. The significant MRI features were incorporated into the logistics regression analysis to build a predictive model for responsible contacts. Results Compared with non-responsible contacts, NVC grading and arterial compression ratio (84.44%) were significantly higher, Dpons-contact was significantly lower at responsible contacts ( P < 0.001, 0.002, and 0.033, respectively). NVC grading had a highest diagnostic area under the ROC curve (AUC) of 0.742, with a sensitivity of 64.44% and specificity of 75.00%. The logistic regression model showed a higher diagnostic efficiency, with an AUC of 0.808, sensitivity of 88.89%, and specificity of 62.04%. Conclusion Contact degree and position are important MRI features in identifying the responsible contacts of the trigeminal neuralgia. The logistic predictive model based on Dpons-contact, NVC grading, and vascular origin can qualitatively improve the prediction of responsible contacts for radiologists.

TRIGEMINAL NERVE RADIOSURGICAL TREATMENT IN INTRACTABLE CHRONIC CLUSTER HEADACHE

Neurosurgery ◽  
2006 ◽  
Vol 59 (6) ◽  
pp. 1252-1257 ◽  
Author(s):  
Anne Donnet ◽  
Manabu Tamura ◽  
Dominique Valade ◽  
Jean Régis
Keyword(s):  
Trigeminal Neuralgia ◽  
Cluster Headache ◽  
Trigeminal Nerve ◽  
Chronic Cluster Headache ◽  
High Rate ◽  
Long Term Results ◽  
Complete Relief ◽  
Term Evaluation ◽  
The One

Abstract OBJECTIVE We have previously reported short-term results of a prospective open trial designed to evaluate trigeminal nerve radiosurgical treatment in intractable chronic cluster headache (CCH). Medium- and long-term results have not yet been reported. METHODS Ten patients presenting with a severe and drug-resistant CCH were enrolled (nine men, one woman). The radiosurgical treatment was performed according to the technique usually used for trigeminal neuralgia in our department. A single 4-mm shot was positioned at the level of the cisternal portion of the trigeminal nerve. The median distance between the center of the shot and the emergence of the nerve was 9.35 mm (range, 7.5–13.3 mm). The median of this maximum dose to the brainstem was 8.0 Gy (range, 4.0–11.1 Gy). Mean age was 49.8 years (range, 32–77 yr). Mean duration of the CCH was 9 years (range, 2–33 yr). The mean follow-up period was 36.3 months (range, 24–48 mo). RESULTS Two patients had complete relief of CCH. One patient had a good result with evolution in an episodic form. Seven patients had no improvement. Nine patients developed a new trigeminal nerve disturbance: three developed paresthesia with no hypoesthesia and six developed hypoesthesia, including two patients with deafferentation pain. Only one patient had neither paresthesia nor hypoesthesia. CONCLUSION We confirmed, with medium- and long-term evaluation, the high rate of toxicity and failure of the technique. The high toxicity, despite a methodology identical to the one used in trigeminal neuralgia, leads us to suspect an underlying specificity of the nerve in CCH. We do not recommend radiosurgery for treatment of intractable CCH.

scholarly journals Neuralgias of the Trigeminal Nerve

2000 ◽  
Vol 5 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Allan S Gordon
Keyword(s):  
Neuropathic Pain ◽  
Differential Diagnosis ◽  
Trigeminal Neuralgia ◽  
Clinical Features ◽  
Trigeminal Nerve ◽  
Postherpetic Neuralgia ◽  
Facial Pain ◽  
The Other ◽  
Atypical Facial Pain ◽  
Trigeminal Neuropathic Pain

Practitioners are often presented with patients who complain bitterly of facial pain. The trigeminal nerve is involved in four conditions that are sometimes mixed up. The four conditions - trigeminal neuralgia, trigeminal neuropathic pain, postherpetic neuralgia and atypical facial pain - are discussed under the headings of clinical features, differential diagnosis, cause and treatment. This article should help practitioners to differentiate one from the other and to manage their care.

Effect of 5% Lidocaine Medicated Plaster on Pain Intensity and Paroxysms in Classical Trigeminal Neuralgia

2014 ◽  
Vol 48 (11) ◽  
pp. 1521-1524 ◽  
Author(s):  
Stefano Tamburin ◽  
Vittorio Schweiger ◽  
Francesca Magrinelli ◽  
Maria Paola Brugnoli ◽  
Giampietro Zanette ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Pain Intensity ◽  
Trigeminal Nerve ◽  
Signs And Symptoms ◽  
C Fibers ◽  
Randomized Controlled Studies ◽  
Reduction Of Pain ◽  
Peripheral Afferents ◽  
Systemic Side Effects ◽  
Third Line

Objective: Trigeminal neuralgia (TN) is a neuropathic pain condition affecting one or more branches of the trigeminal nerve. It is characterized by unilateral, sudden, shock-like, and brief painful attacks, which follow the distribution of trigeminal nerve branches, and with no other accompanying sensorimotor or autonomic signs and symptoms. Current guidelines stipulate which therapies represent first-, second-, and third-line treatments for TN, but there is a consistent mismatch between the therapeutic guidelines and the patient’s preferences and expectations. Case Summary: We report on 2 patients with classical TN in whom conventional drugs for TN were not tolerated. In these patients, treatment with 5% lidocaine medicated plaster (LMP) resulted in reduction of pain intensity and the number of pain paroxysms. Discussion: LMP is known to block the sodium channels on peripheral nerves and may cause a selective and partial block of Aδ and C fibers. According to the TN ignition hypothesis, blockage of peripheral afferents by LMP may reduce pain paroxysms. The effect of LMP may outlast the pharmacokinetics of the drug by reducing pain amplification mechanisms in the central nervous system. LMP has limited or no systemic side effects. Conclusions: LMP may be an effective and well-tolerated treatment option for TN in those patients who do not tolerate or who refuse other therapies. Future randomized controlled studies should better address this issue.

Targeting the cranial nerve: microradiosurgery for trigeminal neuralgia with CISS and 3D-Flash MR imaging sequences

2005 ◽  
Vol 102 ◽  
pp. 107-110 ◽  
Author(s):  
Vasilios A. Zerris ◽  
Georg C. Noren ◽  
William A. Shucart ◽  
Jeff Rogg ◽  
Gerhard M. Friehs
Keyword(s):  
Mr Imaging ◽  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Trigeminal Nerve ◽  
Cranial Nerve ◽  
Fusion Imaging ◽  
Vascular Compression ◽  
Content Type ◽  
History Of ◽  
Fine Print

Object.The authors undertook a study to identify magnetic resonance (MR) imaging techniques that can be used reliably during gamma knife surgery (GKS) to identify the trigeminal nerve, surrounding vasculature, and areas of compression.Methods.Preoperative visualization of the trigeminal nerve and surrounding vasculature as well as targeting the area of vascular compression may increase the effectiveness of GKS for trigeminal neuralgia. During the past years our gamma knife centers have researched different MR imaging sequences with regard to their ability to visualize cranial nerves and vascular structures. Constructive interference in steady-state (CISS) fusion imaging with three-dimensional gradient echo sequences (3D-Flash) was found to be of greatest value in the authors' 25 most recent patients.In 24 (96%) out of the 25 patients, the fifth cranial nerve, surrounding vessels, and areas of compression could be reliably identified using CISS/3D-Flash. The MR images were acceptable despite patients' history of microvascular decompression, radiofrequency (RF) ablation, or concomitant disease. In one of 25 patients with a history of multiple RF lesions, the visualization was inadequate due to severe trigeminal nerve atrophy.Conclusions.The CISS/3D-Flash fusion imaging has become the preferred imaging method at the authors' institutions during GKS for trigeminal neuralgia. It affords the best visualization of the trigeminal nerve, surrounding vasculature, and the precise location of vascular compression.

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