Botulinum toxin treatment failures in cervical dystonia: causes, management, and outcomes

• Type of Material: Article
• Authors: Hyder Jinnah, Emory University; Emily Goodmann, Emory University; Ami Rosen, Emory University; Marian Evatt, Emory University; Alan Freeman, Emory University; Stewart Factor, Emory University
• Language: English
• Date: 2016-04-24
• Publisher: Springer
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2016, Springer-Verlag Berlin Heidelberg. The final publication is available at Springer
• Final Published Version (URL): http://dx.doi.org/10.1007/s00415-016-8136-x
• Title of Journal or Parent Work: Journal of Neurology, Neurosurgery and Psychiatry
• ISSN: 0022-3050
• Volume: 263
• Issue: 6
• Start Page: 1188
• End Page: 1194
• Grant/Funding Information: This work was supported in part by a grant to the Dystonia Coalition (U54 TR001456 and NS065701), a consortium of the Rare Diseases Clinical Research Network (RDCRN) an initiative of the Office of Rare Diseases Research (ORDR) at the National Center for Advancing Clinical and Translational Studies (NCATS) in collaboration with the National Institute for Neurological Diseases and Stroke (NINDS).
• Keywords: TORTICOLLIS; ANTEROCOLLIS; Botulinum toxin; IMMUNOGENICITY; Neurosciences & Neurology; ONSET; MUSCLE; SECONDARY NONRESPONSE; Treatment resistance; Clinical Neurology; Treatment failure; Science & Technology; SATISFACTION; Life Sciences & Biomedicine; MOVEMENT-DISORDERS; SPREAD; LONG-TERM EFFICACY
• Research Categories: Biology, Genetics; Biology, Neuroscience

Abstract

Botulinum toxin (BoNT) is highly effective in the treatment of cervical dystonia (CD), yet a significant proportion of patients report low levels of satisfaction following treatment and fail to follow up for repeated treatments. The goal of this study was to determine the reasons that some patients have unsatisfactory responses. A total of 35 subjects who came to our center requesting alternative treatments due to unsatisfactory responses following BoNT treatment for CD were evaluated. Included were 26 women and 9 men with an average age of 57.1 years (range 25–82 years), and an average duration of illness of 12.5 years (range 1–55 years). Details of unsatisfactory BoNT treatments were methodically collected by a movement specialist using a standardized intake form, including provider subspecialty, product used, the number of satisfactory or unsatisfactory trials, doses given, specific muscles treated, the use of electromyographic guidance, side effects, and tests of resistance. The specialist then provided repeat treatments if indicated, and followed each case until the reasons for unsatisfactory outcomes could be determined. Multiple reasons for unsatisfactory outcomes were found. They included suboptimal BoNT doses, suboptimal muscle targeting, intolerable side effects, complex movement patterns, discordant perceptions, and incorrect diagnoses. Only one patient was functionally resistant to BoNT. Of 32 subjects who received repeat BoNT treatments, 25 (78 %) achieved satisfactory responses after revision of the original treatment plan. These results indicate that the majority of unsatisfactory responses to BoNT treatment of CD were caused by correctible factors and imply a need for improved education regarding optimal treatment methods.