WIRELESS HIGH FREQUENCY SPINAL CORD STIMULATION FOR THE TREATMENT OF POST-HERPETIC OCULAR NEURALGIA: A CASE REPORT

Background: High frequency wireless Spinal Cord Stimulation (SCS) at the C1-C2 vertebral levels provides analgesia for the treatment of refractory ocular pain on the left side secondary to post-herpetic neuralgia. Objective: To assess analgesic effects of minimally invasive wireless neuromodulation in the treatment of chronic pain due to post-herpetic neuralgia. Study Design: This observational, prospective case report was designed to illustrate the effectiveness of relieving chronic, intractable pain utilizing wireless spinal cord stimulation at multiple frequencies for the treatment of post-herpetic neuralgia. Setting: Private Practice Interventional Pain Clinic. Methods: This is a single case study of a 62-yearold patient who experienced an episode of shingles with rash over the left frontal and lateral ocular margin. After the rash subsided, the patient began suffering from severe pain in the left eye. The patient was placed on a 10-day course of valacyclovir, gabapentin, which was discontinued secondary to sedation intolerance, pregabalin titrated to 300 mg/day and oxycodone, all of which were ineffective in relieving the pain. The patient received a stellate ganglion block injection on 6 occasions, experiencing pain relief of only up to one-day after each injection. Stellate ganglion radiofrequency ablation was also unsuccessful. With original Visual Analog Scale (VAS) score of 9/10, inability to sleep and incapacity to perform activities of daily living (ADLs), the patient had Stimwave Freedom wireless stimulators placed sequentially at the C1-C2 vertebral levels. Results: Programming at low frequencies from 40-120 Hz was unsuccessful in reducing left eye pain. Stimulation was increased to high frequency on the Stimwave SurgeTM adjustable waveform, and within 12 hours, the patient noted significant decrease in pain. At 3 days post-procedure, the patient’s VAS score was 1/10. The patient had permanent placement of the devices, and at 8-month follow-up, VAS scores were 0-2/10, and the patient’s mood, sleep and ability to perform ADLs all improved substantially. Limitations: The study was limited by the novelty of the device. Although the doctor who implanted the device is very experienced, more cases of the use of the wireless Stimwave Freedom apparatus are necessary to establish its long-term effectiveness and safety. More clinical trials investigating the utilization of multiple frequencies are also required. Conclusions: Epidural placement of 2, wireless sequentially placed octopolar stimulators with a minimally invasive technique at high frequency stimulation was safe and effective. Key words: post-herpetic neuralgia, ocular, spinal cord stimulation, wireless, shingles, trigeminal nerve, high frequency