Decompression Of Trigeminal Nerve Research Articles

Abnormal electromyographical trigeminal activation through stimulation of the offending artery (Z-L response): An intraoperative tool during microvascular decompression for trigeminal neuralgia.

There are currently no intraoperative neurophysiological tools to assess the effectiveness of trigeminal nerve decompression during microvascular decompression surgery for drug-resistant trigeminal neuralgia. In microvascular decompression surgery for hemifacial spasm, an abnormal electromyographic activation of facial muscles after stimulation of the offending vessel was identified and named 'Z-L response'. We adapted a neurophysiological protocol to elicit a Z-L response during microvascular decompression surgery for trigeminal neuralgia and applied it to a prospective series of 18 surgical patients. Patients had suffered from trigeminal neuralgia for a median 9-year timeframe, and median preoperative Barrow Neurological Institute pain score was 4.5. Through monopolar stimulation, using rising amplitudes starting from 0.1 mA, we confirmed intraoperatively the true culprit vessel before decompression. In 4/18 cases, multiple offending vessels were identified (22 conflicts overall). After decompression, a significant increase in activation threshold (p < 0.0001) confirmed the effectiveness of the maneuver; in 10 cases, Z-L response was abolished. Using this technique, we obtained excellent or good outcome (Barrow Neurological Institute 1-3) in all patients, with a significant reduction in postoperative Barrow Neurological Institute score as compared with preoperative one (median Barrow Neurological Institute 1; p = 0.0002). we provide the first evidence on the applicability and clinical usefulness of Z-L response during microvascular decompression surgery for trigeminal neuralgia.

Fenestrated Aneurysm Clip Trigeminal Decompression after CyberKnife Treatment Failure

Fenestrated Aneurysm Clip Trigeminal Decompression after CyberKnife Treatment Failure

Radiosurgical Decompression of Trigeminal Nerve and Its Correlation with Functional Outcome in Tumor-Related Trigeminal Neuralgia

BackgroundThe target selection during gammaknife radiosurgery(GKRS) in cases of tumor related trigeminal neuralgia(TRTGN) is always debatable. Here we discuss the correlation of regression of tumor size, degree of release of the nerve with long term pain control. MethodsTotal 50 cases of TRTGN were treated with GKRS (tumor was targeted) during the period March 2012 and March 2023. Post GKRS radiology was categorised in to three types(Type 1 – tumor volume remained same/reduced, additional segment of nerve not seen, Type 2 – tumor volume reduced, additional segment of trigeminal nerve seen but tumor still adherent to the nerve, Type 3 – tumor volume reduced, adjacent nerve seen completely separated from tumor). Pre and post GKRS pain score(BNI I to III –good, BNI IV&V – poor) was correlated with the above subgroups. ResultAt a median follow up of 46.5 months 18 cases have type 1, 23 showed type 2 and 9 showed type 3 radiological response. Ten(55.5%) patients with type 1, 15(65.21%) with type 2 and 7(77.8%) with type 3 responses had good pain control. The outcome among these three was not statistically significant(p=0.519).Five patients with type 3 radiological response were off medication which was statistically better than type 1 radiological response with three patients(p = 0.012) and type2 radiological response with two patients(p = 0.002). ConclusionPost GKRS tumor volume reduction may show good pain control in TRTGN. This further allows visualization of additional segment of nerve that can be targeted in the second session for treating recurrent or failed cases.

Fenestrated Aneurysm Clip Trigeminal Decompression after CyberKnife Treatment Failure.

Objective This article describes a novel technique for trigeminal nerve decompression in the setting of refractory trigeminal neuralgia (TN). Design Technical note with an illustrative case example and operative video. Setting Outpatient, inpatient, and operating room of a quaternary neurosurgical referral center. Participant A woman in her early 70s who had previously undergone linear accelerator-based stereotactic radiotherapy (i.e., CyberKnife) and achieved 2 years of partial pain relief. However, facial pain, numbness, and parasympathetic dysfunction returned and became unbearable. Main Outcome Measure Durable relief of TN. Results Microvascular decompression was recommended for refractory TN. Intraoperatively, the trigeminal nerve was markedly attenuated from previous irradiation, with the superior cerebellar artery (SCA) loop embedded in the nerve at its root entry zone. The arterial loop was mobilized into a new position superior to the nerve, thus liberating it from the impingement. The tentorium was incised, and a fenestrated aneurysm clip was positioned such that the SCA loop was transmitted via the fenestration. The clip was applied across the tentorium, thus suspending the artery in a kink-free orientation that made no contact with the nerve. Conclusion This procedure provided excellent neurovascular decompression without placing mechanical strain on the nerve, relieving the patient's persistent postirradiation TN. The technique could have broader applications for other challenging or atypical microvascular decompression procedures.

Magnetic resonance imaging-guided surgical strategies for treating trigeminal neuralgia without vascular compression

ObjectiveTo describe the surgical strategy, curative effect and postoperative complications of trigeminal neuralgia (TN) without vascular compression using head magnetic resonance imaging (MRI). MethodsWe retrospectively enrolled 184 patients with TN who were admitted to the Department of Neurosurgery of Zhoukou Central Hospital from January 2018 to March 2021 and had complete clinical data. Preoperative MRI reveled that 35 patients (19.0%) had no vascular compression. Among them, 16 (45.7%) had simple venous compression during surgery, 9 (25.7%) had venous compression and arachnoid adhesion during surgery, 5 (14.3%) had arachnoid adhesion during surgery, 3 (8.6%) had no venous compression or arachnoid adhesion during surgery, and 2 (5.7%) had simple artery compression during surgery. During the operation, the corresponding surgical strategies for the various types of venous compression were developed. Postoperative efficacy was assessed using the Barrow Neurological Institute pain intensity and facial numbness scores. ResultsAccording to the four types of compression identified during the operation, which did not reveal obvious vascular compression on preoperative head MRI, appropriate decompression methods were found to effectively relieve or eliminate pain (97.1%), and the postoperative effect was relatively satisfactory. There was no recurrence after 1–2 years of follow-up. After operation, two patients (5.7%) experienced occasional pain, one patient (2.9%) reported minor pain, and two patients (5.7%) reported numbness on the affected side of the face. Furthermore, one patient had aseptic meningitis (2.9%) and one patient (2.9%) had transient tinnitus or hearing loss on the affected side. ConclusionFor patients with (TN) without vascular compression on head MRI prior to surgery, different surgical strategies can be implemented based on microvascular decompression and adequate trigeminal nerve decompression findings. Our results showed that these strategies could achieve satisfactory postoperative results without increasing postoperative complications.

Trigeminal radiculopathy in vestibular schwannomas

To evaluate the correlation of trigeminal radiculopathy with anatomical relationships of trigeminal nerve root, brainstem, tumors and vessels in patients with vestibular schwannomas. A retrospective analysis included 153 patients (106 females and 47 males aged 22-82 years) with vestibular schwannomas who underwent surgery via retromastoid approach. Preoperative trigeminal radiculopathy (facial pain and sensory disturbances) was examined after microsurgical resection. Brainstem compression was analyzed by comparison of transverse size of contralateral to vestibular schwannoma half of brainstem and ipsilateral side. Tumor-induced brainstem and trigeminal nerve compression was found in 115 cases. Sixty-four of these patients had trigeminal radiculopathy symptoms. Degree of brainstem compression was significantly higher in trigeminal radiculopathy group. Facial hypoesthesia was found in 61patients, trigeminal neuralgia - in 5 cases, neuropathic pain - in 3 patients. Thirty-seven patients without brainstem compression had no trigeminal nerve involvement. One patient had trigeminal neuralgia following compression by superior cerebellar artery. Total resection with brainstem and trigeminal nerve decompression were performed in all cases. Isolated or combined compression of trigeminal nerve root was noted in 9 patients with trigeminal neuralgia and neuropathic pain, in 2 with facial numbness and in 2 patients without trigeminal symptoms. In case of trigeminal neuralgia following compression by superior cerebellar artery, vascular decompression was performed only in patients with facial pain and numbness. Facial pain completely resolved in all patients. Complete or partial sensory restoration was noted in 25 cases. No facial sensory disorders were noted in 26 cases, transient sensory deterioration - in 10 patients. Trigeminal radiculopathy is caused by severe brainstem compression following vestibular schwannomas and usually results sensory disturbances and rarely facial pain. The impact of tumor on trigeminal nerve root and brainstem trigeminal pathways can be accompanied by vascular compression by superior cerebellar artery. Regression of trigeminal radiculopathy symptoms after resection of vestibular schwannoma is caused by decompression of trigeminal nerve root and brainstem. In case of concomitant neurovascular syndrome, vascular decompression is indicated.

Microvascular Decompression for Trigeminal Neuralgia: A Durable, Noncompressive Technique Using Teflon Secured With Mini Clip.

In cases of trigeminal neuralgia, the importance of durable separation of involved vessels from the trigeminal nerve as well as avoiding ongoing or recurrent compression by implanted material has been affirmed in recent literature. To demonstrate a novel and straightforward technique for trigeminal nerve decompression using a construct of Teflon felt patty (Bard Peripheral Vascular, Tempe, Arizona) secured with an aneurysm mini clip to achieve lasting results with no residual contact between implant or vessels and the nerve. Description of our technique and accompanying surgical video. As demonstrated in the video, this technique achieves an ideal, durable separation of the trigeminal nerve from the offending vasculature. The authors present a description of a technique for decompression with the goal of leaving no contact between implanted material and the nerve. This is accomplished by securing the Teflon felt (Bard Peripheral Vascular) to the tentorium with an aneurysm clip.

Current issues of trigeminal neuralgias of compressive origin. Results of surgical treatment regarding the iatrogenias influence

Objective. To study the results of surgical treatment of classical and symptomatic trigeminal prosopalgias of compressive origin; to define the influence of iatrogenias and thus to improve the treatment provided for this cohort of patients.Materials and methods. Retrospective case series assay of 43 patients with trigeminal neuralgia of compressive origin was performed. The groups were formed regarding the sequence of treatment procedures. Group 1 included 15 patients with TN (3 patients with symptomatic TN and 12 persons with classic TN) who had undergone trigeminal nerve decompression as a primary measure. Group 2 consisted of 28 patients with TN (5 symptomatic and 23 classic) operated after destructive procedures performed previously.Results. Treatment outcomes were significantly worse in the 2nd group where destructive procedures were primary treatment options. Mean BNI PS on the 1st postoperative day were 1.2 vs 2.2 for groups 1 and 2, respectively (Р=0.01; 95% CI 0.25–1.78). At one-year of follow-up period the parameters were 1.13 vs 2.43 (P=0.0006; 95% CI 0.59–2). Average BNI NS score after one year was significantly worse in group 2 — 2.43 vs 1.27 in group 1 (P &lt; 0.0001; 95% CI 0.67–1.65). 100% of group 2 and only 27% of group 1 had clinically significant neuropathy at one-year follow-up period after surgery with RR=3.75 (P=0.002; 95% CI 1.62–8.68).Conclusions. We suggest that destructive procedures as a primary measure for treatment of trigeminal neuralgias of compressive origin lead to worse long-term outcomes and reduce effectiveness of reconstructive technique of microsurgical decompression option.

Suprafloccular approach via the petrosal fissure and venous corridors for microvascular decompression of the trigeminal nerve: technique notes and clinical outcomes.

OBJECTIVE Surgical exposure and decompression of the entire trigeminal nerve in a conventional lateral supracerebellar approach can be challenging because of blockages from the superior petrosal vein complex, cerebellum, and vestibulocochlear nerve. The authors demonstrate a novel suprafloccular approach via the petrosal fissure and venous corridors that can be used as a substitute for the conventional route used to treat trigeminal neuralgia and present a consecutive series of patients and their clinical outcomes. METHODS Preoperative and postoperative clinical data from 420 patients who underwent this modified approach at Hangzhou First People's Hospital between March 2012 and May 2014 were reviewed. The technique expands the working space by opening the petrosal fissure and dissecting adhesions between the vein of the cerebellopontine fissure and the simple lobule as needed. Via 3 surgical corridors, the entire trigeminal nerve is exposed and decompressed thoroughly with minimal retraction of the surrounding vital structures. RESULTS The medial one-third of the trigeminal nerve accounted for the majority (275 [65.5%] cases) of neurovascular conflict sites. The lateral corridor was used in 219 (52.1%) cases, the medial corridor was used in 175 (41.7%) cases, and the intermediate corridor was used in 26 (6.2%) cases. The entire trigeminal nerve in each patient was accessed directly and decompressed properly. At the end of the 24-month follow-up period, the rate of excellent results (Kondo score of T0 or T1) was stable at approximately 90.5%. No complications were related directly to petrosal vein or vestibulocochlear nerve injury. CONCLUSIONS Based on data from the large patient series, the authors found this suprafloccular approach via the petrosal fissure and venous corridors provides full exposure and decompression of the entire trigeminal nerve, a high cure rate, and a low neurovascular morbidity rate.

Trans-cerebellar-fissure approach and via-venous corridor in microvascular decompression for trigeminal neuralgia

Objective To summarize the efficacy and experience of trans-cerebellar-fissure approach and via-venous corridor in microvascular decompression (MVD) of trigeminal neuralgia (TN). Methods The clinical data, operation videos and outcomes of 420 patients with TN treated between March 2014 and September 2015 at Department of Neurosurgery, Hangzhou First People's Hospital were retrospectively analyzed. Results Among all patients, 219 cases (52.1%) had a sufficient exposure of trigeminal nerve after dissection through cerebellar petrosal fissure and lateral venous corridor. An extra opening of medial or intermediate venous corridor was needed for the other 201 cases (47.9%) to fully expose and decompress the fifth cranial nerve. No severe complications including death, disability, petrosal vein injures, hearing disturbance or facial paralysis directly caused by cerebellar retraction occurred. There were 3 (0.7%) patients developing severe facial numbness, 1 patient (0.2%) undergoing reoperation to evacuate cerebellar hematoma and 1 patient (0.2%) reporting permanent hearing loss post surgery by erroneous coagulation of a labyrinth artery. All patients were followed up for 9-30 months with an average of 24.0±8.5 months. At 1 month post operation, the rate of excellent outcomes (T0+ T1) was 94.0% (395 cases) and increased to 96.0% (403 cases) after 3 months with the remission of some non-specific symptoms. Pain recurrence was reported in 5.5% (23 cases) of all patients (23 case), and the overall rate of excellent outcomes was 91.0% (382 cases) at the end of follow-up. Conclusions Trans-cerebellar-fissure approach and via-venous corridor could be beneficial supplements for conventional approach of MVD in helping provide sufficient exposure of decompression of trigeminal nerve and reduce injuries of the petrous vein, facial and trigeminal nerves. Key words: Trigeminal neuralgia; Microvascular decompression; Vein; Petrosal fissure

The value of MRI TOF and CISS sequence to the operation of trigeminal neuralgia decompression

Objective To demonstrate the spatial relationship between intracisternal segment of trigeminal nerve and adjacent vessels in patients with primary trigeminal neuralgia and to assess the effectiveness of magnetic resonance imaging (MRI) for diagnosis of the neurovascular contact.Methods 89patients underwent trigeminal nerve decompression operation from January 2011 to November 2012.Preoperative 1.5T MRI with axial time-of-flight (TOF) sequence and constructive interference in steady state (CISS) sequence were performed.And then the bilateral spatial relationship between intracisternal segment of trigeminal nerve and adjacent vessels were studied.The surgical video recordings were golden standards for comparative analysis of the different results between TOF,CISS and CISS + TOF.Results Confirmed by the operative video recordings,the contact vessels were superior cerebellar artery in 32 cases (35.6％),anterior inferior cerebellar artery in 3 cases (3.3％),vein in 8 cases (8.9％),composite vessels in 44 cases (48.9％),no obvious vascular in 3 cases (3.3％).The accuracies of TOF,CISS,and CISS + TOF to for the diagnosis of the neuralgia side were 56.7％,53.4％ and 56.2％,respectively.The sensitivities of TOF,CISS,and CISS + TOF for the diagnosis of the existence of contact vessels on the neuralgia sides were 74.7％,85.1％ and 93.1％,respectively.The difference between TOF and CISS + TOF was statistically significant.However,the consistency of all three groups for the diagnosis of the type of contact vessels was low,from 0％ to 55.6％.Conclusions Preoperative MRI could not accurately determine the trigeminal neuralgia pain in which side.The combined CISS and TOF sequence examination could accurately determine whether the contact vessels existed on the neuralgia sides.But in this study MRI examination could not accurately determine the types of contact vessels. Key words: Trigeminal neuralgia ; Magnetic resonance imaging; Microvascular decompression

Pontine compression caused by “surgiceloma” after trigeminal decompression: case report and literature review

After microvascular decompression of cranial nerve V or VII, Surgicel and Tissucol were used in 200 cases at our institution. They were uneventfully inserted between the impinging artery and pons to keep the vessels away from the cranial nerves and against the tentoriun or the dura covering the rocca petrosa. We report a case in which a patient developed delayed hemiparesis and packed Surgicel without blood was found as the only cause of compression.

Microvascular decompression of the trigeminal nerve in the treatment of SUNCT and SUNA

BackgroundMedical management of short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) is often unsatisfactory.MethodsThe authors report...

Peduncular hallucinosis after sacrifice of veins of the petrosal venous complex for trigeminal neuralgia

Peduncular hallucinosis is characterized by striking visual images, highly colored and mobile, which are recognized by the patient as imaginary. A 50-year-old-man underwent microvascular decompression for a classical right sided trigeminal neuralgia. During the procedure, the petrosal vein and a transverse pontine vein were sacrificed for trigeminal decompression. On the second postoperative day, the patient developed peduncular hallucinosis that disappeared on the forth postoperative day. This is the third case in the literature of peduncular hallucinosis after obliteration of veins of the petrosal venous complex for trigeminal neuralgia. The best policy in cerebellopontine angle surgery is to preserve the petrosal vein whenever possible to avoid complications related to venous congestion.

A modern view on pathogenesis of trigeminal neuralgia

The development and modern view points on trigeminal neuralgia etiology and pathogenesis are presented. The role of the trigeminal root-entry zone demyelination is stated. The optimal method of treatment is the trigeminal nerve decompression and nerve remyelination maintenance.

SUNCT: bilateral hypothalamic activation during headache attacks and resolving of symptoms after trigeminal decompression

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) is a primary head-pain syndrome, which is often refractory to any medical treatment. Concerning the pathophysiology of SUNCT, hypothalamic involvement ipsilaterally to the pain has been suggested based on the clinical features and one functional imaging case report. Here we now report a new case with SUNCT and the concomitant cerebral activation pattern (fMRI) during the pain attacks. In addition to an activation of several brain structures known to be generally involved in pain processing, bilateral hypothalamic activation occurred during the pain attacks, arguing for a central origin of the headache. Interestingly, this patient became completely pain free after surgical decompression of the ipsilateral trigeminal nerve. We hypothesize that in this case with a central predisposition for trigeminal autonomic cephalgias, a peripheral trigger with ectopic excitation might have contributed to the clinical picture of SUNCT.

Extradural Pneumatocele: An Unusual Case of Pulsatile Tinnitus

Our objective is to heighten the awareness of the clinician to the unusual features of latrogenic, pulsatile, yet nonvascular tinnitus. We present the case of an elderly white male with pulsatile tinnitus immediately following microvascular trigeminal decompression. Computed tomography revealed an extradural air collection and mastoidal fistula. The patient noticed resolution of tinnius with digital pressure over the mastoidal operative site. Treatment included exposure of the aerocele with resection of the lateral wall, fistula obliteration with wax, and abdominal fat graft. The patient noted complete resolution of his tinnitus in the recovery room. The etiology of pulsatile tinnitus can be suspected based on history and can be confirmed with corroborative imaging techniques.

Encircling method of trigeminal nerve decompression for neuralgia caused by tortuous vertebrobasilar artery: technical note

BACKGROUND Surgical treatment of trigeminal neuralgia caused by dolichoectatic vertebrobasilar attery presents a difficult problem because of the immobility and the stiffness of the atherosclerotic vessel walls METHODS AND RESULTS A patient with trigeminal neuralgia was treated by a new method of vascular decompression. Preoperative studies demonstrated a dolichoectatic vertebrobasilar artery, and compression of the trigeminal nerve by the artery was confirmed during surgery. The fifth nerve was mobilized away from the artery using a ring shaped piece of silicone rubber Postoperatively, the facial pain completely resolved without complication CONCLUSIONS Trigeminal neuralgia due to nerve compression by tertuous vertebrubasilar artery was successfully treated by an encircling method of vascular decompression.

Intraoperative variability of auditory brain-stem responses during cranial nerve microvascular decompression

The auditory brain-stem response (ABR) recordings of 40 patients who underwent microvascular decompression of cranial nerves V and VII were analyzed. The latencies of waves I, V, and the I-V interpeak interval were examined as a function of subject age, subject gender, operative site, and operative stage. The results indicated that: (1) subject age was not a significant factor in intraoperative ABR variability; (2) significant male-female latency differences were present only in the earlier operative stages; (3) greater latency changes were produced during decompression of the facial nerve than during trigeminal nerve decompression; and (4) greater response variability was present during the later operative stages. The patients' postoperative auditory status was studied to determine the predictive efficiency of three currently used criteria for significant intraoperative latency change.