The aim of this study is to assess the effect of botulinum toxin injection into the upper esophageal sphincter in a double blind, placebo controlled study. Investigators want to assess the effect on symptoms short term (1-20 weeks after BT injection), and long term (48 weeks after BT injection).
This is a prospective double-blind randomized placebo-controlled study. Questionnaires assessing symptoms will be filled out on several occasions. At 20 weeks, a reassessment of symptoms will be done, without unblinding patients or investigator. Failures (to BT or placebo, defined as no clinical improvement or improvement less than 50%) will get the chance to receive a second procedure with active treatment (BT) in open label.