BTA vs Baclofen for Pelvic Myofascial Pain Syndrome

The aim of the study is to test the hypothesis that oral taking of baclofen in therapeutic dosage for 60 days is equally effective as injection of botulinum toxin type "A" in the area of trigger points of the pelvic muscles.

Chronic pelvic pain syndrome (CPPS) is an extremely common disease. The exact epidemiology and socio-economic impact cannot be determined due to its heterogeneity. Thus, according to population studies, CPPS can occur in 12.4% of women aged 18-50 years \[1\]. In turn, myofascial pelvic pain syndrome (MPPS) is often an underappreciated and untreated component of CPPS that occurs in at least 23% of patients and causes their complaints \[2\]. In men diagnosed with chronic prostatitis, in 92% of cases, complaints are caused by muscle spasm and pain in muscle structures, mistakenly interpreted by the patient as prostate pain \[3\]. Often, myofascial syndrome is idiopathic and is associated with problems in the musculoskeletal system. However, in some cases, the primary source is a urological, gynecological or proctological disease. The syndrome is characterized by the appearance of trigger points (TP) - "nodules" in the thickness of striated muscles, which cause distinct local soreness during palpation \[4\].

Treatment of this condition is complex: it includes training in relaxation of the pelvic muscles using a biofeedback therapy \[5\], myofascial release \[6\] and drug therapy. One of the drugs actively used in neurology is baclofen \[7\]. This drug reduces the spasticity of striated muscles. Despite the widespread using of baclofen in the treatment of neurological conditions accompanied by increased muscle tone, there are no qualitative studies evaluating its effectiveness in chronic pelvic pain syndrome.

If conservative therapy is ineffective, injections of botulinum toxin type "A" (BTA) into TP on pelvic floor muscles are the method of choice \[8\]. This method is a third-line treatment: thus, according to the meta-analysis of Fang Yuan Luo et al., which includes 5 RCTs and 12 observational studies, there is not enough convincing data for using BTA as the first line of treatment \[9\]. At the same time, there are a number of studies in which the effect of the introduction of BTA was comparable to the introduction of local anesthetics \[10\] and saline solution \[11\].

Thus, despite the inconsistency of the methods, a comparative study of the efficacy and safety of these drugs, as well as the quality of life of patients after treatment, is of interest.

Eligibility Criteria:
Inclusion Criteria:

* Myofascial pain syndrome (presence of trigger points), confirmed by palpation during examination.
* Ineffectiveness (with subsequent discontinuation) of at least one treatment method, including outpatient physiotherapy and /or oral analgesics, or NSAIDs.

Exclusion Criteria:

* The presence of any organic disease of the pelvic organs requiring active treatment, confirmed by anamnesis, consultation of a specialist (urologist, proctologist, gynecologist) and one of the objective imaging methods: CT, MRI, endoscopical or laboratory methods: general urine analysis or prostate secretion analysis. Such diseases include interstitial cystitis / SBMP, chronic prostatitis types I, II, IIIA according to the NIH classification.
* The presence in the anamnesis of the fact of previously conducted therapy with baclofen or injection of botulinum toxin type "A" into the pelvic floor muscles.
* Individual intolerance to botulinum toxin type "A" and /or baclofen.
* Pregnancy