Impact of GON PRF on Central Sensitization in Migraine Patients

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.

By prospectively evaluating sensory and clinical outcomes over time, this study aims to provide detailed observational data on the potential neuromodulatory effects of GON pulsed radiofrequency on central sensitization and migraine-related disability. The findings are expected to contribute to a better understanding of patient-reported sensory changes following GON PRF and to inform future controlled studies investigating neuromodulation-based interventions in migraine.

Inclusion criteria

• Adults aged 18 years or older

Diagnosis of episodic or chronic migraine according to the International Classification of Headache Disorders, 3rd edition (ICHD-3)

Planned to undergo ultrasound-guided greater occipital nerve pulsed radiofrequency as part of routine clinical care

Ability to complete self-reported questionnaires (CSI, ASC-12, MIDAS)

Willingness and ability to provide written informed consent

Exclusion criteria

• Presence of other primary headache disorders (e.g., cluster headache, tension-type headache as the primary diagnosis)

Secondary headache disorders, including headache attributed to structural, infectious, inflammatory, or vascular causes

Prior greater occipital nerve pulsed radiofrequency treatment within the past 12 months

History of cervical spine surgery, significant cervical trauma, or structural pathology that may interfere with the procedure

Known coagulopathy or current use of anticoagulant therapy that cannot be safely interrupted

Local infection at or near the planned injection site

Severe uncontrolled psychiatric or neurological disorders that may impair study participation or questionnaire reliability

Pregnancy or breastfeeding

Inability to comply with follow-up visits or study procedures