A simplified ultrasonography-guided approach for neurotoxin injection into the obliquus capitis inferior muscle in spasmodic torticollis
- 385 Downloads
The obliquus capitis inferior (OCI) muscle may be crucially involved in generating the tremulous component of spasmodic torticollis. This study was undertaken to evaluate the efficacy of a simplified ultrasonography-guided approach of botulinum neurotoxin injection into the OCI in the management of spasmodic torticollis. Here, a novel off-plane technique of ultrasonography-guided botulinum neurotoxin injection into the OCI is demonstrated on video. We investigated its effect in five patients with tremulous torticollis with only partial response to conventional injection technique not injecting OCI. On ultrasonography the OCI and its neighboring structures (greater occipital nerve, vertebrae C1 and C2) were clearly displayed. Unlike the previously proposed approach with axial OCI imaging and in-plane medio-lateral needle insertion, we applied here an off-plane needle insertion technique. With this, the ultrasonography guidance of needle insertion was easier using the sagittal imaging plane rather than the axial plane. Compared to botulinum neurotoxin injection into more superficial neck muscles only, additional ultrasonography-guided botulinum neurotoxin injection into the OCI led to a higher benefit (self-rated improvement of cervical dystonia, p = 0.026, Mann–Whitney test), especially of the tremulous component (p = 0.007), even though the total botulinum neurotoxin dose was not changed. We conclude that selected patients with tremulous torticollis may benefit from botulinum neurotoxin injection into the OCI.
KeywordsUltrasonography Intramuscular injection Neck muscles Cervical dystonia Botulinum toxin
Compliance with ethical standards
All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Conflict of interest
U.W. has received speaker honoraria and travel reimbursement from Merz Pharma, Ipsen Pharma, Allergan, Bristol-Myers Squibb, Daiichi Sankyo, Bayer Vital and Pfizer, and a research grant from Merz Pharma. A.D. has received speaker honoraria and travel reimbursement from Merz Pharma and Ipsen Pharma. U.M.F. has received speaker honoraria and travel reimbursement from Merz Pharma, Ipsen Pharma, Allergan, Bayer Vital and Desitin.
Video ESM1. The video shows the setting and procedure of ultrasonography- (US-) guidance (combined here with electromyography-guidance) of BoNT injection into the obliquus capitis inferior (OCI) muscle of a patient with spasmodic torticollis. Segment 1: The initial positioning of the ultrasound probe at the patient’s neck is demonstrated. After visualization of the processus spinosus of vertebra C4 the ultrasound probe is shifted in cranial direction in order to display the OCI at the level of vertebra C1. Segment 2: For full display of the OCI muscle on axial imaging plane the ultrasound probe is shifted in medio-lateral direction and slightly twisted with moving the anterolateral part into upwards direction. Segment 3: For optimal display of the OCI muscle belly on sagittal imaging plane the ultrasound probe is twisted by 90 degree. Segment 4: The US-guided insertion of the injection needle (here connected to an electromyography machine) is presented. The needle tip is visible on the screen. Note the electromyography noise demonstrating dystonic activity of the OCI muscle. During the injection of the BoNT the electromyography noise disappears. (MP4 19555 kb)
- Consky ES, Basinki A, Belle L, Ranawaya R, Lang AE (1990) The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS): assessment of validity and inter-rater reliability. Neurology 40(suppl 1):445Google Scholar
- Cordivari C, Misra VP, Vincent A, Catania S, Bhatia KP, Lees AJ (2006) Secondary nonresponsiveness to botulinum toxin A in cervical dystonia: the role of electromyogram-guided injections, botulinum toxin A antibody assay, and the extensor digitorum brevis test. Mov Disord 21:1737–1741CrossRefPubMedGoogle Scholar
- Simpson DM, Hallett M, Ashman EJ, Comella CL, Green MW, Gronseth GS, Armstrong MJ, Gloss D, Potrebic S, Jankovic J, Karp BP, Naumann M, So YT, Yablon SA (2016) Practice guideline update summary: botulinum neurotoxin for the treatment of blepharospasm, cervical dystonia, adult spasticity, and headache: Report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology 86:1818–1826CrossRefPubMedPubMedCentralGoogle Scholar