Esketamine Combined With PRF for Trigeminal Postherpetic Neuralgia

Inclusion Criteria:

1. Ages more than 18 years;
2. Pain persisting for over three months following the onset of the herpes zoster skin rash;
3. Lesions located in the trigeminal nerve or its branches innervated regions；
4. Having an average pain score of at least 4 on a Numeric Rating Scale (NRS, 0 = no pain, 10= worst possible pain)；
5. Planned to perform CT-guided PRF treatment of the gasserian ganglion(GG).

Exclusion Criteria:

1. Obstructive sleep apnoea syndrome;
2. Those who receive other more invasive treatments, such as radiofrequency thermocoagulation (RFT) of GG.
3. A history of systemic immune diseases, organ transplantation, or cancers;
4. A history of severe cardiopulmonary, hepatic, renal dysfunction or coagulation function disorder;
5. A history of schizophrenia, epilepsy, or myasthenia gravis, delirium;
6. Comorbid hyperthyroidism or phaeochromocytoma;
7. Recent history of drug abuse;
8. Having contraindications to esketamine;
9. Communication difficulties.
10. Women who are preparing for pregnancy, in the pregnancy or lactation period.