Neuromodulation for trigeminal neuralgia

Treatment of recurrent trigeminal neuralgia after microvascular decompression: How to select

BACKGROUND

This study aimed to investigate individualized treatment strategies and clinical outcomes in patients with recurrent trigeminal neuralgia after undergoing microvascular decompression (MVD).

METHODS

One hundred forty-four patients with recurrent trigeminal neuralgia after MVD were retrospectively examined and grouped according to treatment. Surgical efficacy and pain recurrence were analyzed as outcomes.

RESULTS

Repeat craniotomy was performed in 31 patients (21.5 %), percutaneous balloon compression (PBC) in 67 (46.5 %), and radiofrequency thermocoagulation (RFT) in 46 (32.0 %). Effectiveness did not differ among the three types of treatment (P = 0.052). The incidence of postoperative complications, including trigeminal nerve cardiac reflex, facial numbness, and mastication weakness, was lower in the craniotomy group than the PBC and RFT groups (P < 0.001). The 5-year pain recurrence rate was significantly higher than the 1-year rate in all groups. Although the 1-year pain recurrence rate did not differ among the groups, the 5-year rate was significantly lower in the repeat craniotomy group than the other groups (P < 0.001).

CONCLUSION

Patients with recurrent trigeminal neuralgia after MVD should be treated based on imaging evaluation and general condition. Repeat craniotomy, PBC, and RFT are all effective. Incidence of postoperative complications and long-term pain recurrence-free survival are superior for repeat craniotomy.

In situ tissue profile of rat trigeminal nerve in trigeminal neuralgia using spatial transcriptome sequencing

BACKGROUND

Trigeminal neuralgia (TN) is the most common neuropathic disorder in the maxillofacial region. The etiology and pathogenesis of TN have not been clearly determined to date, although there are many hypotheses.

OBJECTIVE

The goal of this study was to investigate the interactions between different types of cells in TN, particularly the impact and intrinsic mechanism of demyelination on the trigeminal ganglion, and to identify new important target genes and regulatory pathways in TN.

METHODS

TN rat models were prepared by trigeminal root compression, and trigeminal nerve tissues were isolated for spatial transcriptome sequencing. The gene expression matrix was reduced dimensionally by PCA and presented by UMAP. Gene function annotation was analyzed by Metascape. The progression of certain clusters and the developmental pseudotime were analyzed using the Monocle package. Modules of the gene coexpression network between different groups were analyzed based on weighted gene coexpression network analysis and assigned AddModuleScore values. The intercellular communication of genes in these networks via ligand-receptor interactions was analyzed using CellPhoneDB analysis.

RESULTS

The results suggested that the trigeminal ganglion could affect Schwann cell demyelination and remyelination responses through many ligand-receptor interactions, while the effect of Schwann cells on the trigeminal ganglion was much weaker. Additionally, ferroptosis may be involved in the demyelination of Schwann cells.

CONCLUSIONS

This study provides spatial transcriptomics sequencing data on TN, reveals new markers, and redefines the relationship between the ganglion and myelin sheath, providing a theoretical basis and supporting data for future mechanistic research and drug development.

Neuromodulation for Craniofacial Pain and Headaches

Headaches and facial pain are highly prevalent diseases but are often difficult to treat. Though there have been significant advances in medical management, many continue to suffer from refractory pain. Neuromodulation has been gaining interest for its therapeutic purposes in many chronic pain conditions, including headaches and facial pain. There are many potential targets of neuromodulation for headache and facial pain, and some have more robust evidence in favor of their use than others. Despite the need for more high-quality research, the available evidence for the use of neuromodulation in treating headaches and facial pain is promising. Considering the suffering that afflicts patients with intractable headache, neuromodulation may be an appropriate tool to improve not only pain but also disability and quality of life.

Low-Energy Transcranial Navigation-Guided Focused Ultrasound for Neuropathic Pain: An Exploratory Study

Neuromodulation using high-energy focused ultrasound (FUS) has recently been developed for various neurological disorders, including tremors, epilepsy, and neuropathic pain. We investigated the safety and efficacy of low-energy FUS for patients with chronic neuropathic pain. We conducted a prospective single-arm trial with 3-month follow-up using new transcranial, navigation-guided, focused ultrasound (tcNgFUS) technology to stimulate the anterior cingulate cortex. Eleven patients underwent FUS with a frequency of 250 kHz and spatial-peak temporal-average intensity of 0.72 W/cm2. A clinical survey based on the visual analog scale of pain and a brief pain inventory (BPI) was performed during the study period. The average age was 60.55 ± 13.18 years-old with a male-to-female ratio of 6:5. The median current pain decreased from 10.0 to 7.0 (p = 0.021), median average pain decreased from 8.5 to 6.0 (p = 0.027), and median maximum pain decreased from 10.0 to 8.0 (p = 0.008) at 4 weeks after treatment. Additionally, the sum of daily life interference based on BPI was improved from 59.00 ± 11.66 to 51.91 ± 9.18 (p = 0.021). There were no side effects such as burns, headaches, or seizures, and no significant changes in follow-up brain magnetic resonance imaging. Low-energy tcNgFUS could be a safe and noninvasive neuromodulation technique for the treatment of chronic neuropathic pain.

Percutaneous high cervical spinal cord stimulation for refractory trigeminal neuralgia

Background

Trigeminal neuralgia (TN) is a debilitating pain that affects the dermatomes associated with the trigeminal nerve (V1, V2, and V3). Unfortunately, many medical treatments and surgical procedures fail to sufficiently modulate the pain associated with this condition.

Case Description

This study presents two extreme cases of refractory TN (RTN) that progressed to atypical facial pain and describes successful mitigation of the neuralgia of said cases by percutaneous implantation of upper cervical spinal cord stimulation (SCS). The SCS was designed to target the descending spinal trigeminal tract.

Conclusion

Together, these cases collaborate with the limited literature and further delineate the use and potential advantages of SCS in the treatment of RTN.