Central Sensitization and Migraine Disability Following Greater Occipital Nerve Pulsed Radiofrequency: A Prospective Observational Study

Migraine is a highly prevalent neurological disorder associated with substantial disability, reduced quality of life, and significant socioeconomic burden. Increasing evidence indicates that migraine chronification is closely linked to central sensitization, characterized by enhanced excitability of central nociceptive pathways, impaired pain modulation, and the clinical manifestation of cutaneous allodynia. Persistent central sensitization is considered a key mechanism underlying increased attack frequency, treatment refractoriness, and migraine-related disability.

The greater occipital nerve (GON), originating from the dorsal ramus of the C2 spinal nerve, provides sensory innervation to the occipital region and has direct anatomical and functional connections with the trigeminocervical complex. Modulation of afferent input from the GON has been shown to influence trigeminal nociceptive processing, supporting its role as a therapeutic target in migraine and other primary headache disorders. Although GON blocks may reduce headache burden, their effects are typically transient, highlighting the need for longer-lasting neuromodulatory strategies.

Pulsed radiofrequency (PRF) is a minimally destructive neuromodulation technique that delivers short bursts of high-voltage electrical current while maintaining tissue temperatures below neurodestructive thresholds. Unlike continuous radiofrequency ablation, PRF is believed to exert its effects through neuromodulatory mechanisms rather than structural nerve injury. Previous studies have suggested that GON-targeted PRF may reduce headache frequency and intensity; however, data regarding its effects on central sensitization and sensory amplification in migraine remain limited.

This prospective observational study is designed to evaluate changes in central sensitization, cutaneous allodynia, and migraine-related disability following ultrasound-guided GON pulsed radiofrequency in patients with episodic or chronic migraine. Adult patients meeting International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria for migraine and scheduled for GON PRF as part of routine clinical care will be enrolled. All procedures will be performed under sterile operating room conditions using ultrasound guidance to identify the GON between the obliquus capitis inferior and semispinalis capitis muscles. PRF will be applied with standardized parameters, maintaining electrode tip temperature at or below 42°C.

Participants will undergo clinical assessments at baseline and at 1 and 3 months after the procedure. Central sensitization will be assessed using the Central Sensitization Inventory (CSI), cutaneous allodynia using the Allodynia Symptom Checklist (ASC-12), and migraine-related disability using the Migraine Disability Assessment Scale (MIDAS). In addition, monthly moderate and severe headache days and acute migraine medication use will be recorded. Adverse events related to the procedure will be systematically monitored throughout the follow-up period.