Neurapraxia in patients with trigeminal neuralgia but no identifiable neurovascular conflict during microvascular decompression: a retrospective analysis of 26 cases

Background Microvascular decompression (MVD) is the first choice in patients with classic trigeminal neuralgia (TGN) that could not be sufficiently controlled by pharmacological treatment. However, neurovascular conflict (NVC) could not be identified during MVD in all patients. To describe the efficacy and safety of treatment with aneurysm clips in these situations. Methods A total of 205 patients underwent MVD for classic TGN at our center from January 1, 2015 to December 31, 2019. In patients without identifiable NVC upon dissection of the entire trigeminal nerve root, neurapraxia was performed using a Yasargil temporary titanium aneurysm clip (force: 90 g) for 40 s (or a total of 60 s if the process must be suspended temporarily due to bradycardia or hypertension). Results A total of 26 patients (median age: 64 years; 15 women) underwent neurapraxia. Five out of the 26 patients received prior MVD but relapsed. Immediate complete pain relief was achieved in all 26 cases. Within a median follow-up of 3 years (range: 1.0–6.0), recurrence was noted in 3 cases (11.5%). Postoperative complications included hemifacial numbness, herpes labialis, masseter weakness; most were transient and dissipated within 3–6 months. Conclusions Neurapraxia using aneurysm clip is safe and effective in patients with classic TGN but no identifiable NVC during MVD. Whether this method could be developed into a standardizable method needs further investigation.

Right medium-sized vestibular schwannoma with trigeminal neuralgia post-fractionated radiotherapy

A patient with trigeminal neuralgia secondary to a vestibular schwannoma underwent fractionated radiotherapy without relief of her pain. She was then effectively treated with microsurgical resection of her tumor. Early identification of the lower cranial nerves and the origin of the facial and vestibulocochlear nerves is key to determining the operative corridors for vestibular schwannoma resection. To effectively treat trigeminal neuralgia, the trigeminal nerve root entry zone and motor branch are clearly identified and decompressed. Fractioned radiotherapy does not effectively treat trigeminal neuralgia secondary to vestibular schwannoma compression. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21112

Arteriovenous malformation of the trigeminal nerve root presented with venous congestive edema of the medulla oblongata and upper cervical cord: illustrative case

BACKGROUND Arteriovenous malformation (AVM) of the trigeminal nerve root (TNR) is a rare subtype of the lateral pontine AVM. Most of them are diagnosed when they bleed or exert trigeminal neuralgia. Venous congestive edema is a rare phenomenon caused by TNR AVMs. OBSERVATIONS An 82-year-old man was admitted with progressive limb weakness and dysphasia. Magnetic resonance imaging (MRI) revealed extensive edema of the medulla oblongata and the upper cervical cord with signal flow void at the C3 anterior spinal cord. Vertebral angiography revealed a small nidus fed mainly by the pontine perforating arteries (PPAs). The anterior pontomesencephalic vein (AMPV) was dilated, functioning as the main drainage route. This suggests that venous hypertension triggered the brainstem and upper cervical cord edema. MRI with gadolinium enhancement showed that the nidus was located around the right TNR. Because the nidus sat extrinsically on the pial surface of the right TNR’s base, microsurgical obliteration with minimum parenchymal injury was achieved. Postoperative MRI showed disappearance of the brainstem and cervical cord edema with improved clinical symptoms. LESSONS TNR AVM is rarely associated with brainstem and upper cervical cord edema caused by venous hypertension of the congestive drainage system.

Trigeminal neuralgia secondary to onyx embolization of a right occipital arteriovenous malformation

Background: Trigeminal neuralgia is a debilitating chronic condition characterized by severe recurrent hemifacial pain which is often caused by compression of the trigeminal nerve by an adjacent vessel loop. Microvascular decompression (MVD) surgery is an effective procedure that can lead to full symptomatic relief. Intracranial arteriovenous malformations (AVMs) are primarily congenital abnormalities that may be asymptomatic or manifest as seizures or focal neurologic deficits. They may cause intracranial bleeding and hence are promptly treated, often by endovascular embolization. This procedure is safe but may have a multitude of unpredictable complications. Case Description: A 33-year-old female presented with medically refractory trigeminal neuralgia secondary to Onyx embolization of a right occipital AVM 3 years prior. She underwent surgical exploration and MVD of the trigeminal nerve root which was found to be compressed by the previously embolized superior cerebellar artery. The procedure was successful and full symptomatic resolution was immediately achieved. Conclusion: Postprocedural trigeminal neuralgia is a procedural complication of Onyx endovascular embolization. It may be treated by MVD surgery regardless of the presence or absence of a compressive vascular loop on imaging.

Five-year result of microvascular decompression using video endoscopy in the treatment of classic trigeminal neuralgia with paroxysmal pain syndrome

Background. The incidence of trigeminal neuralgia (TN) is 15 per 100,000 people per year. The effectiveness of the existing conservative methods of therapy does not exceed 50%. The use of carbamazepine doubles the frequency of depressive conditions, and 40% of suicidal thoughts. Purpose of the study. To evaluate the long-term results of microvascular decompression using video endoscopy in the treatment of patients with classical trigeminal neuralgia (cNTN) with paroxysmal facial pain. Methods. At the Federal Research and Clinical Center of the FMBA of Russia in the period from 2014 to 2019. 96 patients with cNTN were operated on in 62 (64%) of whom neuralgia was with paroxysmal facial pain, and in 34 (36%) - with constant pain. The average period from the onset of pain syndrome to surgery was 5 years (from 2 months to 15 years). The maximum pain intensity upon admission to the hospital according to the visual analogue scale (VAS) was 10 points, according to the BNI (Barrow Neurological Institute) pain syndrome scale - V. All patients underwent MIA of the trigeminal nerve root using Teflon, and in 9 patients during surgery used video endoscopic assistance. The average follow-up period after surgery was 3.4 1.7 years (from 1 to 5 years).Results. In all (100%) patients, pain was completely relieved after surgery (BNI - I). Excellent and good results after MVD within 5 years were achieved in 98% of patients (BNI - I-II). Facial hypesthesia, which does not bring discomfort and anxiety (BNI-II), developed in 8% (n = 5) of patients. The use of video endoscopy made it possible to identify vessels compressing the trigeminal nerve root with minimal traction of the cerebellum and cranial nerves. The development of cerebellar edema and ischemia occurred in one (1.6%) patient.Conclusion. The MVD method with video endoscopy is effective in the treatment of patients with cNTN with paroxysmal pain syndrome.

Nerve Splitting and Vascular Transposition for Trigeminal Neuralgia Attribute to Nerve Penetrating Trigeminocerebellar Artery: 2-Dimensional Operative Video

The trigeminocerebellar artery (TCA) is an infrequent anatomic anomaly of the branches originating from the basilar artery. It is clinically identifiable by the presence of the ipsilateral superior cerebellar artery and the anterior inferior cerebellar artery, and its course from the basilar artery to the cerebellar hemisphere. Because of its anatomic proximity to the trigeminal nerve root, the TCA often causes trigeminal neuralgia (TGN). Unlike other common arteries, repositioning the TCA is not always feasible when it penetrates the trigeminal nerve root (the intraneural type of TCA). In addition, the rich perforators originating from the TCA may limit its movability. The nerve decompression technique in such a rare condition has not yet been fully assessed. In this video, we present the nerve-splitting method for the intraneural type of TCA, in which sufficient isolation of the sensory root is achieved. The motor root of the trigeminal nerve originates from the brainstem slightly rostral of the root entry zone of the sensory root. Dissecting the motor root from its exit to the porous trigeminus allows mobilization of the root together with penetrating TCA away from the sensory root. The movability of the TCA increases by dissecting its perforators to the nerve root and brain stem. Sufficient separation of the sensory root contributes to ensuring the surgical result of nerve decompression and reducing the risk of recurrence due to adhesion. No complications of motor root retraction, such as masseter weakness and malocclusion, were noted in our experience. All data identifying the patients were anonymized. All procedures performed in this study were in accordance with the ethical standards of our institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study also obtained approval from the ethics committee of our institution. Written informed consent was obtained from all individual participants, as well as their first-degree relatives, included in this study.

Microvascular Transposition Without Teflon: A Single Institution's 17-Year Experience Treating Trigeminal Neuralgia

BACKGROUND Trigeminal neuralgia (TN) refractory to medical management is often treated with microvascular decompression (MVD) involving the intracranial placement of Teflon. The placement of Teflon is an effective treatment, but does apply distributed pressure to the nerve and has been associated with pain recurrence. OBJECTIVE To report the rate of postoperative pain recurrence in TN patients who underwent MVD surgery using a transposition technique with fibrin glue without Teflon. METHODS Patients were eligible for our study if they were diagnosed with TN, did not have multiple sclerosis, and had an offending vessel that was identified and transposed with fibrin glue at our institution. All eligible patients were given a follow-up survey. We used a Kaplan-Meier (KM) model to estimate overall pain recurrence. RESULTS A total of 102 patients met inclusion criteria, of which 85 (83%) responded to our survey. Overall, 76 (89.4%) participants responded as having no pain recurrence. Approximately 1-yr pain-free KM estimates were 94.1% (n = 83), 5-yr pain-free KM estimates were 94.1% (n = 53), and 10-yr pain-free KM estimates were 83.0% (n = 23). CONCLUSION Treatment for TN with an MVD transposition technique using fibrin glue may avoid some cases of pain recurrence. The percentage of patients in our cohort who remained pain free at a maximum of 17 yr follow-up is on the high end of pain-free rates reported by MVD studies using Teflon. These results indicate that a transposition technique that emphasizes removing any compression near the trigeminal nerve root provides long-term pain-free rates for patients with TN.

Petrosal Vein Involvement in Neurovascular Conflict in Trigeminal Neuralgia: Surgical Technique and Clinical Outcomes

BACKGROUND Contact of the main stem of the petrosal vein (PV) to the nerve root is a rare cause of trigeminal neuralgia (TGN). The implication of the PV in relation with neurovascular contact (NVC) is not fully understood. OBJECTIVE To assess the operative procedures in microvascular decompression (MVD) in patients with PV involvement in the long-term. METHODS We retrospectively reviewed 34 cases (7.0%) in 485 consecutive MVDs for TGN, whose PV main stem had contact with the trigeminal nerve root (PV-NVC). PV-NVCs were divided into 2 groups: concomitant arterial contact or no concomitant arterial contact. Surgical techniques, outcomes, complications, and recurrence were assessed. RESULTS The anatomical relationship of the PV with the trigeminal nerve root was consistent with preoperative 3-dimensional imaging in all patients. Pain relief was obtained in most patients immediately after surgery (97.1%) by separating the PV from the nerve root. Postoperative facial numbness was noted in 9 patients (26.5%). Symptomatic venous infarctions occurred in 2 patients (5.9%). Recurrence of facial pain occurred in 3 patients (8.8%) with a median 48 mo follow-up period. Re-exploration surgery revealed adhesion being the cause of recurrence. The statistical analyses showed no difference in the surgical outcomes of the 2 groups. CONCLUSION Separating the PV from the nerve root contributes to pain relief in patients with PV conflict regardless of concomitant arteries. Preserving venous flow is crucial to avoid postoperative venous insufficiency.

Basilar artery dolichoectasia an unusual and rare cause of secondary trigeminal neuralgia: a clinical report

Objective: Patients with Trigeminal Neuralgia often consults a dentist for relief of their symptoms as the pain seems to be arising from teeth and allied oral structures. Basilar artery Dolichoectasia is an unusual and very rare cause of secondary Trigeminal Neuralgia as it compresses the Trigeminal nerve Root Entry Zone. Case reports: We report three cases of Trigeminal Neuralgia caused by Basilar artery Dolichoectasia compression. The corneal reflex was found absent in all three of the cases along with mild neurological deficits in one case. Multiplanar T1/T2W images through the brain disclosed an aberrant, cirsoid (S-shaped) and torturous Dolichoectasia of basilar artery offending the Trigeminal nerve Root Entry Zone. Discussion: Based on these findings we propose a protocol for general dentist for diagnosis of patients with trigeminal neuralgia and timely exclusion of secondary intracranial causes. Conclusion: General dentists and oral surgeons ought to consider this diagnosis in patients presenting with chronic facial pain especially pain mimicking neuralgia with loss of corneal reflex or other neurosensory deficit on the face along with nighttime pain episodes. Timely and accurate diagnosis and prompt referral to a concerned specialist can have an enormous impact on patient survival rate in such cases. KEYWORDS Basilar artery; Cirsoid dolichoectasia; Corneal reflex; Trigeminal neuralgia.

Microvascular decompression for trigeminal neuralgia caused by trigeminocerebellar artery

In this operative video, the authors demonstrate the case of a 53-year-old woman who presented with typical right trigeminal neuralgia by a trigeminocerebellar artery (TCA). The TCA was first defined by Marinković as a unique branch of the basilar artery supplying both the trigeminal nerve root and the cerebellar hemisphere. As a result of the close relationship between this vessel and the nerve root, the TCA might compress the nerve root, thereby causing trigeminal neuralgia. However, few cases of trigeminal neuralgia caused by TCA have been reported. This video shows the microvascular decompression for trigeminal neuralgia by the TCA.The video can be found here: https://youtu.be/UnGsCQRK6aY