Esketamine Combined Pulsed Radiofrequency for Acute/Subacute Zoster-associated Trigeminal Neuralgia

Inclusion Criteria: 1. Age \>18 years; 2. History of HZ within the last three months; 3. Lesions located in the trigeminal nerve or its branches innervated regions； 4. Numeric Rating Scale (NRS) pain score≥4 (NRS, 0 = no pain, 10= worst possible pain) with pharmacotherapy; 5. Planned to perform CT-guided PRF treatment of the Gasserian ganglion . Exclusion Criteria: 1. Obstructive sleep apnoea syndrome; 2. Those who receive other invasive treatments, such as spinal cord stimulation; 3. A history of systemic immune diseases, organ transplantation, or cancers; 4. A history of severe cardiopulmonary, hepatic or renal dysfunction; 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. Withdrawal criteria 1. Lost to follow-up during the study; 2. Not perform the planned operation; 3. Receiving other treatment regimes during the study period; 4. Not suitable for continuing the study for emerging severe comorbidities or special physiological changes during the study; 5. Voluntary withdrawal from the study.