Trigeminal neuralgia (TN), characterized by brief, recurrent paroxysms of lancinating pain in the distribution of 1 or more branches of the trigeminal nerve (fifth cranial nerve [CNV]), is one of the most common, severe forms of neuropathic pain. Current standard of care for TN is the sodium channel blockers such as carbamazepine or oxcarbazepine. Surgical treatments involve percutaneous procedures, stereotactic radiosurgery and open surgical treatment. Each of these treatments have drawback. In recent years, pulsed radiofrequency (PRF) has been shown to be a promising treatment option for TN. But it was reported that the long-term outcomes of PRF was not satisfactory. Thus, there is an overwhelming need for finding a safe, nondestructive treatment option that is more effective for TN. PRP releases a variety of bioactive factors and adhesion proteins, which are responsible for activating hemostatic cascade reaction, synthesizing new connective tissue and vascular reconstruction, to initiate tissue repair processes. Autologous platelet-rich plasma (PRP) is the processed liquid fraction of autologous peripheral blood with a platelet concentration above the baseline. Studies have shown that it can reduce inflammation and promote nerve repair so it has also shown broad prospects in treating neuropathic pain. In 2012, Doss AX. published a case report indicated that PRP might be effective in TN treatment. In 2023, a randomized controlled study showed that CT-guided PRF combined with PRP can effectively treat postherpetic neuralgia (PHN), and the therapeutic effect is better than that of traditional PRF combined with glucocorticoid therapy in patients with PHN, which is similar to TN in pathology. Thus, we suppose that PRF combined with PRP might show better effectiveness than PRF alone for TN and conducted a prospective trail comparing the clinical efficacy and safety of PRP combined with PRF versus PRF alone. This study is designed as a prospective cohort study, open-label study with a 12 months follow-up period, to compare the efficacy of PRF combined with PRP versus PRP alone for TN treatment.

Inclusion Criteria:

1. The diagnosis of TN was established according to the International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria (1).
2. Aged 18 to 75 years.
3. Had a score of at least 4 on a Numeric Rating Scale (NRS-11) (NRS; range, 0-10; higher scores indicate more severe pain) and could't be alleviated effectively by means of conservative medical therapy, such as carbamazepine, oxcarbazepine.
4. Agreed to sign the informed consent form.

Exclusion Criteria:

1. Patients presenting classic TN or secondary TN (i.e., multiple sclerosis).
2. Infection at the site of needle entry or systemic infecting.
3. A history of psychiatric disease.
4. Disorder indicated in the results of routine blood tests, hepatic function, renal function, coagulation function, electrocardiogram, or chest x-ray.
5. Serious systemic diseases such as uncontrolled hypertension or diabetes, and cardiac dysfunction (New York Heart Association grade II-III).
6. A history of abuse of narcotics.
7. A history of receiving CRF to the Gasserian ganglion or peripheral branches, glycerol rhizolysis, balloon compression, Gamma knife, or any other neuroablative treatments.
8. A history of receiving microvascular decompression.
9. Use of anticoagulants or antiplatelet agent, eg. acetylsalicylic acid.

The main purpose of this study will be to compare the effectiveness of PRF combined with and without PRP, evaluated 1 year after the procedure. The effectiveness of PRF combined PRP group after 1 year is supposed to be 90%, and that of the high-voltage PRF group was 69% (29) (The α is 0.05, and the power is 90%). Power Analysis and Sample Size (PASS) V.15.0 software (NCSS Corporation, Kaysville, UT, USA) was used to compute the sample size. The results show that 73 patients will be required in each group. However, Accounting for 10% loss to follow-up and an additional 40% loss after propensity score matching, 135 patients will be recruited in each group. Therefore the total sample size of this study is supposed to be 270 participants.