P.356 - Effects of botulinum toxin injections in the cricopharyngeal muscle of OPMD and IBM myopathies with dysphagia

Abstract

Certain myopathies have dysphagia as a pronounced and very troublesome symptom, but no established treatment exists. Botulinum toxin injection in the cricopharyngeal muscle has at case level been reported to be effective. To systematically evaluate the safety and efficacy of injections of botulinum toxin in the cricopharyngeal muscle in patients with dysphagia due to inclusion body myositis (IBM) or oculopharyngeal muscular dystrophy (OPMD). Patients with confirmed diagnoses of IBM or OPMD and dysphagia were included if no other cause for dysphagia was present, and if dysphagia, assessed by a timed water swallow test, a dysphagia questionnaire and by meal registration, was pronounced. Additional baseline registration included body weight, number of pneumonia episodes, muscle strength and enzyme measurements. Initially, laryngoscopia was performed followed by needle electromyography to confirm activity in the cricopharyngeal muscle and to establish needle placement. Botulinum toxin was then injected through the hollow EMG needle. An individualized dose of 5–10 units was applied bilaterally the first time and the dose was then titrated up with at least 12 weeks' intervals. Suspected side effects were noted at each visit. Outcome measures were change in timed water swallowing test, dysphagia questionnaire and meal registration. 12 subjects were included, 3 with OPMD. Preliminary results from 6 subjects show that 4 felt a clear improvement, whereas 2 were excluded due to that a worsening was suspected based on subjective observations and worsening in the meal registration assessment. In the dysphagia questionnaire, however, every single subject improved (p < 0.001). No overall change was seen in the meal registration assessment and the timed water swallow test. Preliminary results suggest a positive effect on dysphagia of cricopharyngeal botulinum toxin in patients with OPMD and IBM.