Efficacy and Safety of Transcranial Temporal Interference Stimulation (tTIS) for Neuropathic Pain in Neuromyelitis Optica Spectrum Disorder (NMOSD)

Inclusion Criteria: * Patients diagnosed with NMOSD in accordance with the criteria of the International Panel for Neuromyelitis Optica Diagnosis (IPND). * Patients were complicated with neuropathic pain, with a DN4 score ≥ 4. * NRS score for pain ≥ 4 points, and neuropathic pain has persisted for more than 3 months. * Patients receiving biological therapy and/or prednisone at a stable dose, with no adjustment of the treatment plan within 30 days before enrollment. * Patients who have not adjusted any combination of standard analgesic drugs (including antiepileptic drugs, antidepressants, and opioid drugs) within 30 days before enrollment. * Patients or their family members who have signed a written informed consent form. Exclusion Criteria: * Subjects participating in other clinical studies. * Subjects who have used investigational drugs for pain control within 30 days before enrollment. * Subjects with a concurrent diagnosis of peripheral neuropathy. * Subjects with concurrent active central nervous system diseases. * Subjects with cognitive or mental disorders. * Subjects who are pregnant, lactating, or planning to become pregnant during the study period. * Subjects with severe diseases related to the heart, liver, kidneys, or hematopoietic system. * Subjects with implanted devices in the body (such as cardiac pacemakers, nerve stimulators, etc.). * Subjects with a history of transcutaneous electrical nerve stimulation (TENS) allergy, latex allergy, or previous intolerance. * Subjects with contraindications to MRI examination. * Subjects with head skin lesions. * Other medical conditions or situations that the researcher deems may affect the achievement of the study objectives.