Comprehensive anatomy of the foramen ovale critical to percutaneous stereotactic radiofrequency rhizotomy: cadaveric study of dry skulls

2020 ◽  
Vol 132 (5) ◽  
pp. 1414-1422
Author(s):  
Adel Elnashar ◽  
Smruti K. Patel ◽  
Almaz Kurbanov ◽  
Kseniya Zvereva ◽  
Jeffrey T. Keller ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Facial Pain ◽  
Preoperative Imaging ◽  
Morphometric Study ◽  
Microsurgical Anatomy ◽  
Foramen Ovale ◽  
Percutaneous Approach ◽  
Head Ct ◽  
Adjacent Structures ◽  
Shape And Size

OBJECTIVEPercutaneous stereotactic radiofrequency rhizotomy (PSR) is often used to treat trigeminal neuralgia, a serious condition that results in lancinating, episodic facial pain. Thorough understanding of the microsurgical anatomy of the foramen ovale (FO) and its surrounding structures is required for efficient, effective, and safe use of this technique. This morphometric study compares anatomical and surgical orientations to identify the variations of the FO and assess cannulation difficulty.METHODSBilateral foramina from 174 adult human dry skulls (348 foramina) were analyzed using anatomical and surgical orientations in photographs from standardized projections. Measurements were obtained for shape, size, adjacent structures, and morphometric variability effect on cannulation. The risk of potential injury to surrounding structures was also assessed.RESULTSThe authors identified 6 distinctive shapes of the FO and 5 anomalous variants from the anatomical view, and 6 shapes from the surgical view. In measurements of surface area of this foramen obtained using the surgical view, loss (average 18.5% ± 5.7%) was significant compared with the anatomical view. Morphometrically, foramen size varied significantly and obstruction from a calcified pterygoalar ligament occurred in 7.8% of specimens. Importantly, 8% of foramina were difficult to cannulate, thus posing a 12% risk of inadvertent cannulation of the foramen lacerum.CONCLUSIONSSignificant variability in the FO’s shape and size probably affected its safe and effective cannulation. Preoperative imaging by 3D head CT may be helpful in predicting ease of cannulation and in guiding treatment decisions, such as a percutaneous approach over microvascular decompression or radiosurgery.

Controlled thermocoagulation of trigeminal ganglion and rootlets for differential destruction of pain fibers

1974 ◽  
Vol 40 (2) ◽  
pp. 143-156 ◽  
Author(s):  
William H. Sweet ◽  
James G. Wepsic
Keyword(s):  
Trigeminal Neuralgia ◽  
Facial Pain ◽  
Electrical Heating ◽  
Gasserian Ganglion ◽  
Foramen Ovale ◽  
Content Type ◽  
Corneal Scarring ◽  
Radiofrequency Heating ◽  
Neurological Morbidity ◽  
Fine Print

✓ The authors report their experience in the treatment of trigeminal neuralgia with controlled increments of radiofrequency heating from an electrode placed in the Gasserian ganglion or its posterior rootlets. Touch is preserved in some or all of a trigeminal zone rendered analgesic. The electrode tip is introduced through the foramen ovale and placed among the desired rootlets with the help of a combination of radiographs and the conscious patient's response to electrical stimulation with a square wave signal and gentle electrical heating. The degree of heat is measured by a thermister at the electrode tip. The patient's cooperation is maintained by the use of the neurolept anesthetic Innovar and the production of brief unconsciousness for the painful parts of the operation by methohexital (Brevital). Of 274 patients with facial pain so treated, 214 had trigeminal neuralgia; 91% of the latter group experienced relief of pain and 125 followed for 2½ to 6 years had a recurrence rate of 22%. In a total of 353 procedures, there has been no mortality and no neurological morbidity outside the trigeminal nerve. Only six of the patients with trigeminal neuralgia have complained significantly of postoperative paresthesias. The most serious undesired result has been the production of an anesthetic cornea in 28 patients, one of whom lost the sight of one eye due to corneal scarring. Correlating findings in our patients with those in studies by other authors, we conclude that the preservation of some touch is due to resistance to heating by the heavily myelinated A-beta fibers.

Unconventional Facial Entry Points Confirmed Using a 3D CT Reconstruction–Guided Stereotactic Approach to Radiofrequency Thermocoagulation for the Treatment of Trigeminal Neuralgia: A Series of Case Reports

Pain Medicine ◽  
2018 ◽  
Vol 20 (8) ◽  
pp. 1551-1558 ◽  
Author(s):  
Zhigang Guo ◽  
Zhijia Wang ◽  
Kai Li ◽  
Chao Du ◽  
Xingli Zhao ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Anatomical Variation ◽  
Preoperative Imaging ◽  
Gasserian Ganglion ◽  
Ct Reconstruction ◽  
Foramen Ovale ◽  
Radiofrequency Thermocoagulation ◽  
Patient Reported ◽  
Entry Points

Abstract Objectives Patients with trigeminal neuralgia who are refractory to medical therapy may choose to undergo Gasserian ganglion percutaneous radiofrequency thermocoagulation. However, in cases where the foramen ovale is difficult to access due to various anatomical anomalies, the typical estimation of the facial entry point is suboptimal. Methods Three-dimensional computed tomography reconstruction imaging performed before surgery revealed anatomical variations in each of the four adult patient cases that made it more difficult to successfully access the foramen ovale (FO) for percutaneous radiofrequency thermocoagulation. Using measurements collected from preoperative imaging that showed each specific anatomical variation in the FO, researchers marked alternate facial entry points that would allow successful probe placement into the FO and recorded the arc angle data in the stereotactic instrument. Results Patients were evaluated during follow-up visits ranging from seven to 26 months after surgery and asked to rate postoperative pain using a visual analog scale. These scores decreased from 10 to 3 in all four patients by the third day after the procedure. There were no permanent complications or morbidities from the surgery. One patient experienced mild facial numbness; however, this side effect subsided within three months after surgery. During the follow-up period, no patient reported pain recurrence. Conclusions The expectation for clinicians approaching trigeminal nerve block using a peri-oral approach should be to expect a great degree of potential variability in terms of both distances from the corner of the mouth and needle angle taken to successfully navigate the anatomy and access the foramen ovale.

scholarly journals Microsurgical anatomy and approaches around the lateral recess with special reference to entry into the pons

2018 ◽  
Vol 129 (3) ◽  
pp. 740-751 ◽  
Author(s):  
Osamu Akiyama ◽  
Ken Matsushima ◽  
Maximiliano Nunez ◽  
Satoshi Matsuo ◽  
Akihide Kondo ◽  
...  
Keyword(s):  
Surgical Approaches ◽  
Morphometric Study ◽  
Microsurgical Anatomy ◽  
Entry Zone ◽  
Lateral Recess ◽  
Fiber Tracts ◽  
Adjacent Structures ◽  
Microsurgical Techniques ◽  
Safe Entry Zone ◽  
Wide Exposure

OBJECTIVEThe lateral recess is a unique structure communicating between the ventricle and cistern, which is exposed when treating lesions involving the fourth ventricle and the brainstem with surgical approaches such as the transcerebellomedullary fissure approach. In this study, the authors examined the microsurgical anatomy around the lateral recess, including the fiber tracts, and analyzed their findings with respect to surgical exposure of the lateral recess and entry into the lower pons.METHODSTen cadaveric heads were examined with microsurgical techniques, and 2 heads were examined with fiber dissection to clarify the anatomy between the lateral recess and adjacent structures. The lateral and medial routes directed to the lateral recess in the transcerebellomedullary fissure approach were demonstrated. A morphometric study was conducted in the 10 cadaveric heads (20 sides).RESULTSThe lateral recess was classified into medullary and cisternal segments. The medial and lateral routes in the transcerebellomedullary fissure approach provided access to approximately 140º–150º of the posteroinferior circumference of the lateral recess. The floccular peduncle ran rostral to the lateral recess, and this region was considered to be a potential safe entry zone to the lower pons. By appropriately selecting either route, medial-to-lateral or lateral-to-medial entry axis is possible, and combining both routes provided wide exposure of the lower pons around the lateral recess.CONCLUSIONSThe medial and lateral routes of the transcerebellomedullary fissure approach provided wide exposure of the lateral recess, and incision around the floccular peduncle is a potential new safe entry zone to the lower pons.

scholarly journals Radiofrequency Thermocoagulation Through Foramen Rotundum Versus Foramen Ovale for the Treatment of V2 Trigeminal Neuralgia

2019 ◽  
Vol 6 (22;6) ◽  
pp. E609-E614
Author(s):  
Cong-yang Yan
Keyword(s):  
Trigeminal Neuralgia ◽  
Facial Pain ◽  
Operation Time ◽  
Controlled Clinical Trial ◽  
Gasserian Ganglion ◽  
Internal Opening ◽  
Foramen Ovale ◽  
Maxillary Nerve ◽  
Radiofrequency Thermocoagulation ◽  
Foramen Rotundum

Background: Percutaneous radiofrequency thermocoagulation through the foramen rotundum (FR) is a new approach for the treatment of V2 trigeminal neuralgia (TN). Objectives: This study aimed to compare the efficacy and safety of the FR approach with that of the foramen ovale (FO) approach. Study Design: Nonrandomized controlled clinical trial. Setting: The study was conducted at Huaian Hospital of Huaian City, Huaian, China. Methods: From July 2014 to December 2016, 80 consecutive patients with V2 TN were prospectively assigned into the FO group (n = 40) or the FR group (n = 40). All radiofrequency thermocoagulation procedures were performed under the guidance of digital subtraction angiography (DSA). Patients in the FO group were treated with Gasserian ganglion ablation through the Hartel approach. Patients in the FR group received ablation of the maxillary nerve at the internal opening of the FR. Facial pain was evaluated using the Visual Analog Scale preoperatively and postoperatively at 1 week, 6 months, and 1 year. Results: All surgical procedures were successfully completed using DSA guidance. The FR group had no facial pain at postoperative 1 week, 6 months, and 1 year. The facial fain was not relieved in 4 patients of the FO group. They were treated with radiofrequency thermocoagulation of the maxillary nerve through the FR and maintained painless at postoperative 1 week, 6 months, and 1 year. At postoperative 1 year, another 3 patients relapsed in the FO group. The incidences of facial numbness and swelling did not differ significantly between the 2 groups (all P > 0.05). There was no postoperative corneal involvement or masticatory weakness in the FR group. However, corneal involvement and masticatory weakness occurred postoperatively in 22 (55%) patients and 31 (77.5%) patients in the FO group. The FR group had significantly shorter operation time than the FO group (19.3 ± 5.9 vs. 32.7 ± 8.7 minutes; P < 0.05). Limitations: We were unable to avoid the V1 and V3 branches, despite multiple adjustments of the needed position in 35 of the 40 patients in this group. Conclusions: For the treatment of V2 TN, thermocoagulation of the maxillary nerve through the FR had better efficacy and fewer complications in comparison with the Gasserian ganglion ablation through the FO

scholarly journals Microsurgical Anatomy of Safe Entry Zones on the Ventrolateral Brainstem: A Morphometric Study

2021 ◽  
Author(s):  
Ilke Bayzıt Kocer ◽  
Mine Oner Demiralin ◽  
Mete Erturk ◽  
Dilek Arslan ◽  
Gulgun Sengul
Keyword(s):  
Trigeminal Nerve ◽  
Inferior Olive ◽  
Careful Analysis ◽  
Anatomical Landmark ◽  
Oculomotor Nerve ◽  
Preoperative Imaging ◽  
Morphometric Study ◽  
Lateral Side ◽  
Microsurgical Anatomy ◽  
Descending Fibers

Abstract Surgery of the brainstem is challenging due to the complexity of the area with cranial nerve nuclei, reticular formation and ascending and descending fibers. Safe entry zones are required to reach the intrinsic lesions of the brainstem. The aim of this study was to provide detailed measurements for anatomical landmark zones of the ventrolateral surface of the human brainstem related to previously described safe entry zones. In this study, 53 complete and 34 midsagittal brainstems were measured using a stainless caliper with an accuracy of 0.01 mm. The distance between the pontomesencephalic and bulbopontine sulci was measured as 26.94 mm. Basilar sulcus-lateral side of pons (origin of the fibers of the trigeminal nerve) distance was 17.23 mm, transverse length of the pyramid 5.42 mm and vertical length of the pyramid 21.36 mm. Lateral mesencephalic sulcus was 12.73 mm, distance of the lateral mesencephalic sulcus to the oculomotor nerve 13.85 mm and distance of trigeminal nerve to the upper tip of pyramid 17.58 mm. The transverse length for the inferior olive at midpoint and vertical length were measured as 5.21 mm and 14.77 mm, consequently. The thickness of the superior colliculus was 4.36 mm, the inferior colliculus 5.06 mm; length of the tectum was 14.5 mm and interpeduncular fossa 11.26 mm. Profound anatomical knowledge and careful analysis of preoperative imaging are mandatory before surgery of the brainstem lesions. The results presented in this study will serve neurosurgeons operating in the brainstem region.

scholarly journals Neuronavigated percutaneous approach to the sphenopalatine ganglion

2017 ◽  
Vol 126 (2) ◽  
pp. 375-378 ◽  
Author(s):  
Nicola Benedetto ◽  
Paolo Perrini
Keyword(s):  
Trigeminal Neuralgia ◽  
Cluster Headache ◽  
Gold Standard ◽  
Facial Pain ◽  
Technical Note ◽  
Sphenopalatine Ganglion ◽  
Atypical Facial Pain ◽  
Percutaneous Approach ◽  
Percutaneous Procedures ◽  
First Time

The sphenopalatine ganglion (SPG) has been assumed to be involved in the genesis of several types of facial pain, including Sluder's neuralgia, trigeminal neuralgia, persistent idiopathic facial pain, cluster headache, and atypical facial pain. The gold standard treatments for SPG-related pain are percutaneous procedures performed with the aid of fluoroscopy or CT. In this technical note the authors present, for the first time, an SPG approach using the aid of a neuronavigator.

Percutaneous Approach to the Foramen Ovale: An Anatomical Study of the Extracranial Trajectory

Skull Base ◽  
2009 ◽  
Vol 19 (03) ◽  
Author(s):  
Jorge Alvernia ◽  
Nguyen Dang ◽  
Patrick Mertens ◽  
Marc Sindou ◽  
Miguel Melgar
Keyword(s):  
Anatomical Study ◽  
Foramen Ovale ◽  
Percutaneous Approach

scholarly journals Percutaneous radiofrequency treatment of the gasserian ganglion for trigeminal neuralgia complicated by trochlear nerve palsy: a case report

2021 ◽  
pp. rapm-2020-102285
Author(s):  
Pascal SH Smulders ◽  
Michel AMB Terheggen ◽  
José W Geurts ◽  
Jan Willem Kallewaard
Keyword(s):  
Trigeminal Neuralgia ◽  
Cranial Nerve ◽  
Facial Pain ◽  
Anatomical Variations ◽  
Anterior Inferior Cerebellar Artery ◽  
Gasserian Ganglion ◽  
Radiofrequency Treatment ◽  
Experienced Pain ◽  
Cerebellar Artery ◽  
Trochlear Nerve Palsy

BackgroundTrigeminal neuralgia (TN) has the highest incidence of disorders causing facial pain. TN is provoked by benign stimuli, like shaving, leading to severe, short-lasting pain. Patients are initially treated using antiepileptic drugs; however, multiple invasive options are available when conservative treatment proves insufficient. Percutaneous radiofrequency treatment of the trigeminal, or gasserian, ganglion (RF-G) is a procedure regularly used in refractory patients with comorbidities. RF-G involves complex needle maneuvering to perform selective radiofrequency heat treatment of the affected divisions. We present a unique case of cranial nerve 4 (CN4) paralysis after RF-G.Case presentationA male patient in his 60s presented with sharp left-sided facial pain and was diagnosed with TN, attributed to the maxillary and mandibular divisions. MRI showed a vascular loop of the anterior inferior cerebellar artery without interference of the trigeminal complex. The patient opted for RF-G after inadequate conservative therapy. The procedure was performed by an experienced pain physician and guided by live fluoroscopy. The patient was discharged without problems but examined the following day for double vision. Postprocedural MRI showed enhanced signaling between the trigeminal complex and the brainstem. Palsy of CN4 was identified by a neurologist, and spontaneous recovery followed 5 months after the procedure.ConclusionsMention of postprocedural diplopia in guidelines is brief, and the exact incidence remains unknown. Different mechanisms for cranial nerve (CN) palsy have been postulated: incorrect technique, anatomical variations, and secondary heat injury. We observed postprocedural hemorrhage and hypothesized that bleeding might be a contributing factor in injury of CNs after RF-G.

scholarly journals A novel method to treat recurrent facial pain: a case report

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Jintakorn Kuvatanasuchati ◽  
Karoon Leowsrisook
Keyword(s):  
Case Report ◽  
Trigeminal Neuralgia ◽  
Facial Pain ◽  
Case Presentation ◽  
Facial Movements ◽  
Novel Treatment ◽  
Effective Cost ◽  
Novel Method

Abstract Background Chronic facial pain is a serious condition affecting millions of people worldwide. The reasons for chronic facial pain vary, and currently, the methods of treating chronic facial pain are expensive, invasive, and, based on current findings, ineffective. The purpose of this study is to develop and test an effective, cost-friendly method to treat patients with chronic facial pain. This study will examine the effectiveness of a novel treatment of a patient suffering from trigeminal neuralgia. Case presentation A 70-year-old Thai female visited the advanced general dentistry clinic at the Faculty of Dentistry, Mahidol University, Bangkok, Thailand. She was suffering from facial pain on her left side and was diagnosed by a physician as having trigeminal neuralgia. She experienced a sharp shooting pain that was triggered by facial movements such as chewing, speaking, or brushing teeth, and touching certain areas of her face. Bouts of pain lasted from a few seconds to several minutes, and episodes of several attacks lasted days, weeks, months, or longer prior to her visit to the advanced general dentistry clinic at Mahidol University. Physician designed an occlusal equilibration appliance for treating the patient by inserting the appliance in the mouth for dental occlusal equilibration (deprogram). The patient used this appliance by placing it in the mouth continuously (day and night) and removed it only when eating. After using the appliance for 2 weeks, the patient appeared to feel and look better prior to taking medication and was able to eat normally. The patient was pain free after treatment for a duration of 9 months. However, after 9 months, the pain reoccurred and manifested itself. Conclusion This novel treatment of recurrent facial pain showed an improvement of the patient’s chronic facial pain and serves as evidence to being a novel method for treating those suffering from trigeminal neuralgia.

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.

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