Effect of acupuncture on fMRI and Iowa Gambling Task (IGT) in postherpetic neuralgia (PHN) patients

INTERVENTION: PHN patients were randomized to receive acupuncture (Ashi point), or sham acupuncture for 3 weeks Rescue medication ‐ Oxycodone 5‐30mg/day orally (or more) was used as rescue medication for pain controlled at more than 3 on the VAS and the frequency of acute pain flare‐ups more than 3 times per day. CONDITION: Postherpetic neuralgia ; Mental and Behavioural Disorders ; Cranial nerve disorders in diseases classified elsewhere PRIMARY OUTCOME: 1. fMRI signal change, IGT results at baseline and 14 days after treatment; 2. Visual Analogue Scale (VAS), measured at baseline and 1, 2, 3,7 and 14 days after treatment; 3. Pain flare‐ups per day during days 3, 7, 14 after treatment SECONDARY OUTCOME: 1. SF‐36 at baseline, 14 days after treatment; 2. Dosage of rescue drug (Oxycodone) consumed per day at 3, 7, and 14 days after treatment; 3. Presence, frequency and duration of adverse effects at 7 and 14 days after treatment INCLUSION CRITERIA: 1. Age greater than 60 years 2. Weighs over 40kg 3. History of pain is longer than 3 months 4. Pain on Visual Analogue Scale (VAS) >3 (0‐10 VAS scale), with acute pain flares that occurred more than 3 times per day 5. Refractory to formal treatment such as antiepileptic medicine, antidepressants, opioids, physical treatments and epidural block 6. No history of severe liver and renal diseases 7. PHN patents whose pain area was at T1‐12 level 8. Male and female participants