Cervical dystonia: Improved treatment response to botulinum toxin after referral to a tertiary centre and the use of polymyography

RationaleCervical dystonia is the most common form of (primary) dystonia. The first line of treatment for cervical dystonia is intramuscular injections with botulinum toxin. To optimise the response to botulinum toxin proper muscles selection is required. Pre-treatment polymyographic EMG in addition to clinical evaluation is hypothesised to be a good tool to improve muscle selection and treatment outcome.ObjectiveTo determine the efficacy of botulinum toxin treatment after adjacent polymyographic EMG in cervical dystonia patients referred to our tertiary referral centre with an unsatisfactory response to botulinum toxin treatment elsewhere.MethodsWe performed a retrospective analysis of 40 consecutive second opinion cervical dystonia patients. Standard polymyographic EMG was performed before treatment. We retrieved the Tsui scores and subjective evaluations from the first visit, after 12 weeks and after one year of treatment. In addition, we assessed the final outcome of treatment in our centre based on the records and asked the patients for their personal opinion about the effect of referral to our centre on their treatment response.ResultsAfter one year of treatment there was a significant improvement on both the Tsui scores (p < 0.01) and the subjective treatment evaluation (p < 0.001.) On their last visit 60% of the patients still continued treatment with a reasonable to good response.ConclusionA substantial amount of CD patients with an unsatisfactory response to botulinum toxin improved after polymyography and subsequent treatment with botulinum toxin in a tertiary referral centre.