Scrambler Therapy for the Treatment of Pain in Schwannomatosis

[Features of course of pain syndrome in patients with schwannomatosis]

OBJECTIVE

To identify the characteristics of pain syndrome in patients with schwannomas depending on genetic predisposition.

MATERIAL AND METHODS

The study included 46 patients with peripheral, spinal and intracranial schwannomas, corresponding to the schwannomatosis phenotype according to the 2022 clinical criteria. All patients underwent sequencing of the LZRT1, Nf2 and SMARCB1 and a copy number study in the NF2.

RESULTS

The most severe widespread pain was observed in patients with pathogenic LZRT1 variants, while patients with mosaic variants may not even have local tumor-related pain. Patients with SMARCB1variants may have no pain or have localized pain that responds well to surgical treatment.

CONCLUSION

Further studies of the molecular features of schwannomatosis and driver mutations in the pathogenesis of pain are necessary to improve the effectiveness of pain therapy in this group of patients. Schwannomatosis is a disease from the group of neurofibromatosis, manifested by the development of multiple schwannomas. Neuropathic pain is one of the main symptoms characteristic of peripheral schwannomas, however, the severity and prevalence of the pain syndrome does not always correlate with the location of the tumors. According to modern concepts, the key factors influencing the characteristics of the pain syndrome are the target gene and the type of pathogenic variant. The most severe widespread pain is observed in patients with pathogenic variants in the LZRT1 gene, while patients with mosaic variants may not even have local pain associated with tumors. Patients with variants in SMARCB1 may have no pain or localized pain that responds well to surgical treatment.

Successful Treatment of Paraneoplastic Neuropathy and Pruritis With Scrambler Therapy: A Case Report

Paraneoplastic neuropathy, including pruritis, remains a vexing problem as it often does not resolve even with successful treatment of cancer. Scrambler Therapy is a superficial form of neuromodulation that replaces the pain signal with “non-pain information” that is approved for chronic and neuropathic pain, with few side effects. We report here two cases of paraneoplastic neuropathy, one with additional pruritis, that both responded satisfactorily to Scrambler Therapy with no side effects.