An interventional study of Greater Occipital Nerve Pulsed Radiofrequency (Unilateral) and Bilateral GON PRF Treatment: in Migraine, Greater Occipital Nerve Pulsed Radiofrequency, Headache Disorders and Ultrasound Guided Nerve Block, sponsored by Ankara City Hospital Bilkent. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-05-07.
Sponsored by Ankara City Hospital Bilkent · Not applicable, Interventional, and Treatment
This study is designed to compare the clinical effectiveness of unilateral and bilateral Greater Occipital Nerve Pulsed Radiofrequency (GON-PRF) treatment at the C2 level in patients with migraine. The procedure will be guided by ultrasound and will focus on evaluating how each technique affects migraine symptoms.
The main goal of this study is to assess the impact of both unilateral and bilateral GON-PRF treatments on migraine relief. Additionally, the secondary objectives of this study include evaluating the effects of these treatments on migraine-related disability and comparing any potential side effects or complications that may occur during the treatments.
This research will help us understand which technique may be more effective and provide more information on the safety of these treatments.
Migraine is a common neurological disorder that significantly affects quality of life and socio-economic functioning. In patients with headaches resistant to conservative pharmacological treatment, peripheral nerve interventions, particularly greater occipital nerve (GON) block, are frequently used. GON block can reduce the frequency and intensity of migraine attacks and may decrease the need for systemic medications. However, the duration of benefit following GON block with local anesthetics and steroids is often limited to several weeks or months.
To prolong the therapeutic effect of peripheral nerve interventions, pulsed radiofrequency (PRF) has been introduced. PRF modulates pain transmission by generating an electrical field around the targeted nerve without causing structural nerve damage. Greater occipital nerve pulsed radiofrequency (GON PRF) has been reported to be both effective and safe in the treatment of migraine and is widely used in pain management practice.
GON block and GON PRF procedures can be performed using anatomical landmark techniques or under ultrasound guidance. Two ultrasound-guided approaches have been described: a proximal technique targeting the nerve at the C2 vertebral level and a distal technique targeting the superior nuchal line. The proximal (C2) approach has been shown to provide effective results in migraine treatment.
Although the exact mechanism of long-term headache relief following peripheral nerve interventions remains unclear, it is believed to involve central pain modulation. The upper cervical nerve roots are anatomically and functionally connected with trigeminal pathways, converging within the trigeminocervical complex. Neurophysiological findings suggest that unilateral nerve interventions may produce bilateral inhibitory effects through modulation of second-order neuronal transmission.
Retrospective clinical observations indicate that unilateral GON interventions may provide similar reductions in headache frequency, severity, and duration compared to bilateral applications, with potentially fewer side effects. However, there is currently no prospective study directly comparing unilateral and bilateral GON PRF in patients with migraine.
In our clinic, GON PRF is performed under sterile operating room conditions with standard monitoring and intravenous access. For the proximal (C2) approach, patients are positioned prone with slight neck flexion. Under ultrasound guidance, anatomical landmarks including the obliquus capitis inferior and semispinalis capitis muscles are identified. The GON is visualized as an oval hypoechoic structure between these muscles. A 22-gauge RF cannula with a 5 mm active tip is inserted using an in-plane technique. After sensory stimulation confirms appropriate localization, PRF is applied at 45 V, 5 Hz, and 5 ms pulse width for 360 seconds, ensuring that electrode tip temperature does not exceed 42°C. No medications are injected during the PRF procedure. For bilateral treatment, the same procedure is performed contralaterally. Patients are observed for at least one hour post-procedure prior to discharge.
The primary objective of this study is to prospectively compare the clinical efficacy of unilateral and bilateral ultrasound-guided proximal (C2 level) GON PRF treatment in patients with migraine. Secondary objectives include evaluation of migraine-related disability outcomes and assessment of treatment-related adverse events and complications.
1,657 studies on the registry are indexed under Migraine Disorders; 339 are open to participants now.
This study's enrollment of 217 is above the median of 80 across 1,269 interventional studies indexed under Migraine Disorders.
Browse Migraine Disorders studies →Ankara City Hospital Bilkent is the lead sponsor of 443 studies on the registry; 111 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This arm involves applying unilateral greater occipital nerve pulsed radiofrequency (GON PRF) at the C2 level using ultrasound guidance. The procedure is performed on one side of the head (unilateral).
Other: Greater Occipital Nerve Pulsed Radiofrequency (Unilateral)
This arm involves applying bilateral greater occipital nerve pulsed radiofrequency (GON PRF) at the C2 level using ultrasound guidance. The procedure is performed on both sides of the head (bilateral).
Other: Bilateral GON PRF Treatment:
Greater Occipital Nerve (GON) Pulsed Radiofrequency (PRF) treatment is performed under sterile conditions in the operating room. The patient is positioned in the prone position with neck flexion. Under ultrasound guidance at the proximal (C2) level, the needle is carefully placed near the GON, targeting the space between the Obliquus Capitis Inferior (OCI) muscle and C2's bifid spinous process. After proper sterilization, a linear ultrasound probe is used transversely over the occipital protuberance to locate the C1 and C2 vertebrae. Once identified, the RF needle and electrode are inserted laterally to medially using in-plane technique. A sensory stimulation test is done, and the PRF therapy is applied at a 45V setting, 5 Hz, and 5 ms pulse width for 360 seconds, with a maximum temperature of 42°C. No drug injections are administered during the procedure. Post-procedure, the patient is monitored for at least 1 hour before discharge after a general and neurological evaluation.
Also known as: UGON-PRF
Greater Occipital Nerve (GON) Pulsed Radiofrequency (PRF) treatment is performed under sterile conditions in the operating room. The patient is positioned in the prone position with neck flexion. Under ultrasound guidance at the proximal (C2) level, the needle is carefully placed near the GON, targeting the space between the Obliquus Capitis Inferior (OCI) muscle and C2's bifid spinous process. After proper sterilization, a linear ultrasound probe is used transversely over the occipital protuberance to locate the C1 and C2 vertebrae. Once identified, the RF needle and electrode are inserted laterally to medially using in-plane technique. A sensory stimulation test is done, and the PRF therapy is applied at a 45V setting, 5 Hz, and 5 ms pulse width for 360 seconds, with a maximum temperature of 42°C. No drug injections are administered during the procedure. Post-procedure, the patient is monitored for at least 1 hour before discharge after a general and neurological evaluation. Bilater
Also known as: BGON-PRF
Mean change in monthly headache days from baseline to 6 months
Monthly headache days are defined as calendar days with headache lasting ≥4 hours with at least moderate intensity, or any headache requiring acute migraine medication use. Note: The primary outcome was defined as monthly headache days according to the study protocol. VAS scores are retained as secondary outcomes.
Time frame: Baseline and 6 months after treatment
Change in Headache Intensity (VAS)
Average headache intensity measured using a 10-point Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst imaginable pain). Higher scores indicate greater pain intensity (worse outcome).
Time frame: Baseline, 1 month, 3 months, and 6 months after treatment
Change in MIDAS Grade
The Migraine Disability Assessment (MIDAS) questionnaire assesses headache-related disability over the previous 3 months by quantifying days of missed work, household, and social activities. In this study, MIDAS was recorded as categorical grades (Grade I-IV), with higher grades indicating greater disability. Changes from baseline to follow-up time points will be analyzed.
Time frame: Baseline, 3 months, and 6 months after treatment
Change in Headache Impact Test-6 (HIT-6) Score
The Headache Impact Test-6 (HIT-6) questionnaire assesses the impact of headaches on daily functioning. The total score ranges from 36 to 78, with higher scores indicating greater headache-related impact (worse outcome). Changes from baseline to follow-up time points will be analyzed.
Time frame: Baseline, 3 months, and 6 months after treatment
Global Perceived Effect (GPE)
The 7-point Global Perceived Effect (GPE) scale is a patient-reported measure of overall change in headache symptoms and functional status. Scores range from 1 (very much worse) to 7 (very much improved), with higher scores indicating greater clinical improvement. A score of ≥6 is considered to represent clinically meaningful improvement.
Time frame: 1 month, 3 months, and 6 months after treatment
Acute Medication Use Days
Number of days in which acute migraine medications (e.g., analgesics, NSAIDs, triptans, ergot derivatives, opioids) were used to relieve headache.
Time frame: Baseline and monthly follow-up for 6 months
Adverse Events
Any adverse events or complications related to unilateral or bilateral GON PRF treatment, including type, severity, and duration.
Time frame: Up to 6 months after treatment
Plan to share: No — Individual participant data (IPD) will not be shared with other researchers due to confidentiality constraints and data protection policies.
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Ankara City Hospital Bilkent →