Analgesic Effect of an Injection of Botulinum Toxin Type A in the Ganglion Impar in Patients With Chronic Proctalgia

Inclusion Criteria: * Age \> 18 years * Patient with chronic proctalgia according to the criteria of Rome III * Chronic or recurrent rectal pain * Pains evolve over periods of at least 20 minutes * With the exclusion of other causes of rectal pain: ischemic, inflammatory bowel disease, cryptic lesions, intramuscular abscess, anal fissure, hemorrhoids, prostatitis and isolated coccydynia * Pains evolve in a regular way since more than 3 months and the symptoms started since at least 6 months * These chronic proctalgia include syndromes of anus elevator and nonspecific functional anorectal pains * Patient with positive anesthetic block of ganglion Impar (minimum of 30 days before D0 and maximum of 270 days before D0) * Main score (SP) ≥ 4 before infiltration of botulinum toxin type A * Signed informed consent * Subjects affiliated with an appropriate social security system Exclusion Criteria: * Pain related malignancy * Patients with bleeding risk and recent anticoagulant therapy * Surgery within 3 months * Pre-existing anal incontinence * Intolerance of botulinum toxin A, local anesthetics and radio contrast medium * Injection of botulinum toxin in any place whatsoever in the previous 3 months * Pregnancy and breast feeding * Antibiotic treatment by aminoglycosides * Recent anti-inflammatory treatment * Severe myasthenia * Lambert-Eaton syndrome * Patients with neurological disorders, dysphagia, food choking or inhalation pneumonia