Trigeminal neuralgia caused by a dilated superior cerebellar artery and a draining vein of cerebellar arteriovenous malformations: a case report and review of the literature

The Superior Cerebellar Artery: Variability and Clinical Significance

The superior cerebellar artery (SCA) arises from the distal part of the basilar artery and passes by the oculomotor, trochlear, and trigeminal nerves. SCA is known to play a crucial role in the development of trigeminal neuralgia. However, due to its anatomical variability, it may also trigger other neurovascular compression (NVC), including hemifacial spasm, oculomotor nerve palsy, and ocular neuromyotonia. Additionally, it may be associated with ischemic syndromes and aneurysm development, highlighting its clinical significance. The most common anatomical variations of the SCA include duplication, a single vessel origin from the posterior cerebral artery (PCA), and a common trunk with PCA. Rarely observed variants include bifurcation and origin from the internal carotid artery. Certain anatomical variants such as early bifurcation and caudal course of duplicated SCA trunk may increase the risk of NVC. In this narrative review, we aimed to examine the impact of the anatomical variations of SCA on the NVCs based on papers published in Pubmed, Scopus, and Web of Science databases with a snowballing approach. Our review emphasizes the importance of a thorough understanding of the anatomical variability of SCA to optimize the management of patients with NVCs associated with this artery.

Microvascular decompression in trigeminal neuralgia with the offending artery transfixing the nerve: a case report

Background

An anterior inferior cerebellar artery (AICA) that crosses the right trigeminal nerve is an uncommon arterial anatomic variation. In this anatomical position, it is difficult to separate or move the offending blood vessels and nerves. We report an uncommon case of trigeminal neuralgia (TN) caused by compression of the trigeminal ganglion by a branch of the AICA.

Case presentation

A 34-year-old man with 5 years history who complained of pain on the right side of the face (area V1). The symptoms gradually worsened, and the pain episodes became intense and frequent. Magnetic resonance imaging (MRI) of the cerebrum showed a small blood vessel passing through the right trigeminal nerve. Microvascular decompression (MVD) was performed,because medication was ineffective. Intraoperative exploration confirmed that the vessel which was a branch of the AICA passing through the right trigeminal nerve. As while the artery was temporarily clipped, electrophysiological monitoring showed a decrease in the amplitude of nerve activity. As the artery was considered too important to be sacrificed, the space between the nerves was enlarged mildly, the artery was liberated, the Teflon implant was shredded and placed between the artery branches and nerve to make the blood vessels as perpendicular as possible to the nerve. The patient had no neurological dysfunction and no pain after 8 months of follow-up.

Conclusion

MVD is an effective treatment for artery-induced trigeminal nerve compression, but we report a novel procedure that avoids the complication of facial numbness caused by cutting the offending vessels and incision of the trigeminal nerve.

Trigeminal Neuralgia Secondary to Cerebellar Arteriovenous Malformation: A Report of Two Cases

Trigeminal neuralgia (TN) secondary to cerebellar arteriovenous malformation (cAVM) is a rare condition with only few reports existing in the literatures. Given to its rarity, the treatment armamentarium is still controversial. We reported our experiences treated two cases of TN secondary to cAVM using different strategies. The first case was successfully treated by a combination of gamma knife radiosurgery and microvascular decompression (MVD) of the trigeminal nerve. The second case was successfully treated by one-step microsurgical AVM resection and MVD of the trigeminal nerve. Postoperative immediate pain relief was achieved in both patients. Microsurgical procedure is still playing an important role in treating TN secondary to cAVM.

A Study on the Recurrence Rate of Trigeminal Neuralgia after MVD and the Related Factors

The aim of this article is to investigate the related factors affecting the recurrence of microvascular decompression (MVD) after trigeminal neuralgia. We selected 400 cases of patients who met the diagnostic criteria of primary trigeminal neuralgia. The recurrence rate of patients and their statistical data related factors such as age, gender, disease duration, pain branches, vascular compression, patients, and complications (urban and rural), were collected. Of the 400 cases, 36 had recurrence after 2 years. In female group, the recurrence rate was (9.4%) higher than the recurrence rate in male group (8%); no recurrence rate of vascular compression group (40%) was higher than that of vascular compression group recurrence rate (8.6%); the recurrence rate of each branch in pain group from high to low was V _2-3 (13.4%), V ₂ (12.5%), V ₁ (9.1%), V ₃ (7.5%), V _1-2-3 (4.4%), V _1-2 (4.3%), V _1-3 (0%); and the difference was statistically significant ( p  < 0.05).Gender of the patient, the presence of vascular pressure, and the branch of pain could significantly affect the postoperative recurrence rate of trigeminal neuralgia in patients treated with simple MVD ( p  < 0.05).

Right Retrosigmoid Approach for In Situ Occlusion of Brainstem Arteriovenous Malformation Surrounding the Trigeminal Nerve: 3-Dimensional Operative Video

Arteriovenous malformations (AVMs) of the trigeminal root entry zone are rare and can be associated with neurovascular compression syndromes as well as intracranial hemorrhage.1 They generally have a small nidus located on and around the pial surface of the brainstem; thus, they are feasible for surgery. Nevertheless, they represent a challenge given the vicinity and involvement of cranial nerves and brainstem perforators.2-4This video demonstrates the case of a 57-yr-old man with new onset of a severe headache without neurological deficit associated with MRI evidence of a vascular malformation around the cisternal right trigeminal nerve. The nerve showed an altered signal on the MRI. Angiography revealed a Spetzler-Martin grade II AVM with a 16-mm nidus supplied by basilar artery perforators, right anterior inferior cerebellar artery, and the superior cerebellar artery (SCA), with drainage into the superior petrosal vein and sigmoid sinus. After an unsuccessful attempted embolization, the patient was referred for and elected microsurgical treatment. With the patient in a lateral position, a right retrosigmoid approach was performed. After cisternal dissection and identification of the nidus, the feeders were occluded by alternating cauterization and clipping to avoid damage to the critical surrounding structures. The AVM in-situ occlusion was carried on without resection, given the involvement of the trigeminal nerve. The intraoperative indocyanine green angiography allowed recognition of the venous drainage and helped to localize and differentiate the feeders from normal perforators. In the immediate postoperative course, the patient suffered from mild numbness with a V2-V3 distribution that progressively improved. Angiography showed no residual AVM.

Genome-wide analysis of circular RNAs in bovine cumulus cells treated with BMP15 and GDF9

Circular RNAs (circRNAs) are important members of the non-coding RNA family, and those relating to animal physiologies have been widely studied in recent years. This study aimed to explore the roles of circRNAs in the regulation of follicular development. We constructed four bovine cumulus cell cDNA libraries, including a negative control group (NC) and groups treated with BMP15, GDF9 and BMP15 + GDF9, and we sequenced the libraries on the Illumina HiSeq Xten platform. We identified 1706 circRNAs and screened for differential circRNA expression. We conducted a bioinformatics analysis of these circRNAs and screened for differential circRNAs. Functional annotation and enrichment analysis of the host genes showed that the differential circRNAs were related to locomotion, reproduction, biological adhesion, growth, rhythmic processes, biological phases and hormone secretion. According to the differential expression of circRNA between groups, there were 3 up-regulated and 6 down-regulated circRNAs in the BMP15 group as well as 12 up-regulated and 24 down-regulated circRNAs in the GDF9 group. Co-addition of both BMP15 and GDF9 resulted in 15 up-regulated and 13 down-regulated circRNAs. circ_n/a_75,circ_12691_1 and circ_n/a_303 were altered in both the BMP15 and GDF9 groups as well as in the BMP15 + GDF9 combination group. We focused on these three circRNAs because they were potentially associated with the additive effect of BMP15 and GDF9. Quantitative PCR analysis showed that the expression levels of these three circRNAs were consistent with the sequencing results. In addition, the target miRNAs of circ_n/a_75 and circ_n/a_303, miR-339a, miR-2400 and miR-30c, were down-regulated in the experimental group, which was in contrast to the circRNAs trend. These findings demonstrated that BMP15 and GDF9 may regulate the target gene through circRNA, as a miRNA sponge, in order to regulate the status of bovine cumulus cells and affect follicular development.