EA for BPS: An RCT and Study for Central Mechanism

Participants will be primarily recruited from gynecology, urology and acupuncture departments during outpatient service. All patients will be randomly assigned to either the medication group, EA group or SA group via random number table. SAS 9.3 software will be adopted to generate random numbers. The independent clinical research assistant will be responsible for generating random numbers and making random allocation cards, each with its group allocation information and sealed into an opaque envelope, which will not be open until the first treatment. According to the order of enrollment, eligible participants will be randomly assigned into the medication, EA or SA group at 1:2:1 ratio under the allocation in the envelope.

Due to the characteristics of acupuncture, acupuncture manipulators cannot be blinded. Nevertheless, to avoid the subjective bias of researchers and subjects, outcome assessment and statistical analysis will be performed by different researchers blinded to the allocation information. Patients are informed that they will receive one of two effective acupuncture interventions after enrollment, and during the treatment, patients in EA or SA groups will be in separate rooms to avoid communication. Outcome assessors and statisticians will be blind to the group allocations. The participant's allocated intervention will not be revealed until the statistical analysis reports are completed.

Participants in the medication group will be merely treated with oral administration of amitriptyline capsule. The dosage of amitriptyline is 25 mg bid, for 4 weeks. Any changes in the medications of individual participants will be recorded on diary cards.

In EA group, acupuncture treatment is carried out by acupuncturists who have been well trained. Acupuncture will be performed with disposable and sterile needles in the specification of 0.25 ×40 mm(diameter: 0.25 mm; Suzhou Medical Products Factory Co., Ltd, China). Patients are asked to lie in a prone position with whole body relaxed. Both the skin around the selected acupoints and the hand of acupuncturists are routinely disinfected, after insertion, manipulations of twirling, lifting and uniform reinforcing reducing manipulation will be performed on all needles to elicit 'deqi'. The compositional sensation of 'deqi' involves with numbness, soreness, distention, aching and heaviness, which are believed to be an essential component for acupuncture efficacy. Electroacupuncture procedures will be performed with electronic instruments (Hans-100A, Nanjing Jisheng Medical TechnologyCo., Ltd, China). Two paired of acupoints (i.e., two Shenshu(BL23) and two Ciliao(BL32), respectively) are connected to the EA apparatus. Alternating-frequency mode is selected and frequency is 2/100 Hz. EA intensity is determined in accordance with patients' endurance. EA will last for 30 min for each treatment. Patients will receive a total number of 12 EA sessions, with the frequency of 3 sessions per week for 4 weeks.

In SA group, Acupuncture will be conducted by well-trained acupuncturists and performed with disposable and sterile needles in the specification of 0.25×40 mm (diameter: 0.25 mm; Suzhou Medical Products Factory Co., Ltd, China). Patients are asked to lie in a prone position with whole body relaxed. Both the skin around the selected acupoint and the hand of acupuncturists are routinely disinfected. The needles are subcutaneously inserted to non-meridian and non-acupoints regions. SA procedures will be performed with electronic instruments (Hans-100A, Nanjing Jisheng Medical Technology Co., Ltd, China). Two paired of points are connected to the electronic instruments. Alternating-frequency mode is selected and the frequency is 2/100 Hz. Different from the EA group, the apparatus will run without electricity in the SA group. The procedure will last for 30 min. Patients will receive a total number of 12 SA sessions, with the frequency of 3 sessions per week for 4 weeks.

Outcomes, such as Visual analog scale, O'Leary-Sant questionnaire, 24-hour voiding diary, Hamilton Anxiety Scale and Hamilton Depression Scale, will be assessed at baseline, during the treatment and at the end of the follow-up. Outcome assessors, data managers and statisticians will be blinded to the group allocation, while acupuncturists and participants will not be blinded for obvious reasons.

Besides, fMRI will be used to collect spontaneous electrical activity of the brain of patients, and the changes of spontaneous electrical activity of specific brain regions, resting brain functional connectivity and information interaction of multifunctional areas will be analyzed.

Inclusion criteria

• 18 ≤ age ≤70 years, male or female;
• Must fulfill the first and the second diagnostic criteria;
• 30 mm≤ VAS score ≤80mm;
• Participants can fully understand the study protocol and a written informed consent is signed.

Exclusion criteria

• Patients with previous bladder stones or other space-occupying lesions;
• Previous positive urine culture or significant abnormal urine routine;
• Significant organic lesions of genitourinary system and pelvic organs;
• Patients suffer from severe primary diseases such as cardiovascular, cerebrovascular, respiratory, liver and kidney, or patients cannot receive EA treatment due to any reasons;
• People with heart stents and other metallic substances in their bodies;
• Women who are pregnant, planning to become pregnant, breast-feeding or allergic to study drugs;
• Patients have participated in other clinical trials within the last 3 months.