2023 American Academy of Neurology Abstract Website

Objective:

To determine whether Transcutaneous Electrical Nerve Stimulation (TENS) therapy is a safe, tolerable, and effective therapy for neuropathic pain in patients with Aquaporin-4 (AQP4) IgG positive Neuromyelitis Optica Spectrum Disorders (NMOSD).

Background:

NMOSD is a chronic relapsing neuroinflammatory disorder that preferentially targets the optic nerves and spinal cord. Pain due to the longitudinally extensive spinal cord lesions seen in NMOSD is a frequent, disabling, and difficult to treat component of the disease with up to 91% of patients reporting symptoms of central neuropathic pain. TENS therapy is a non-invasive pain-modifying intervention that utilizes transcutaneous electrical stimulation of ascending sensory fibers that has been investigated for the amelioration of peripheral neuropathic pain in several other conditions.

Design/Methods:

We conducted a 4-week, randomized, double-blind, sham-controlled, fully remote trial of the QUELL TENS in patients with NMOSD who have central neuropathic pain, followed by a 12-week open label extension period. The Numeric Rating Scale for Pain (NRS-P) was used as the primary outcome measure and was assessed at baseline and at weeks 1, 2, 3, 4, 5, 6, 7, 8, 12, and 16.

Results:

Forty-six patients (23 per arm) were enrolled in this trial, of which 37 completed the trial (3 in the intervention arm and 1 in the sham arm withdrew for adverse events possibly related to the device). Both the sham and intervention arms demonstrated a significant decrease in average pain, worst pain, and current pain between the baseline and 4 week periods, however there was no significant difference between the two arms on intention-to-treat primary or secondary efficacy outcomes.

Conclusions:

Both arms demonstrated significant decreases in reported pain between baseline and 4-week follow-up, however there was no demonstrated benefit of TENS over sham. Further trial analysis will be conducted analyzing responder groups, adverse events, and per-protocol results based on device usage data.