Management of Anterocapitis and Anterocollis: A Novel Ultrasound Guided Approach Combined with Electromyography for Botulinum Toxin Injection of Longus Colli and Longus Capitis

• Type of Material: Article
• Authors: Michael Farrell, Georgetown University; Barbara I. Karp, National Institutes of Neurological Disorders and Stroke; Panagiotis Kassavetis, National Institutes of Neurological Disorders and Stroke; William Berrigan, Emory University; Simge Yonter, National Institutes of Health; Debra Ehrlich, National Institutes of Neurological Disorders and Stroke; Katherine E. Alter, National Institutes of Health
• Language: English
• Date: 2020-10-01
• Publisher: MDPI AG
• Publication Version: Final Published Version
• Copyright Statement: © 2020 by the authors.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/toxins12100626
• Title of Journal or Parent Work: Toxins
• Volume: 12
• Issue: 10
• Grant/Funding Information: This work was supported by the Intramural Research Programs of the Warren G. Magnusun Clinical Center and the National Institutes of Neurological Disorders and Stroke at the National Institutes of Health.
• Keywords: cervical dystonia; head and neck; longus capitis; injection technique; botulinum toxins; anterocaput; chemodenervation; longus colli; anterocollis; ultrasound guidance
• Research Categories: Biology, Cell; Health Sciences, Toxicology; Health Sciences, Medicine and Surgery

Abstract

Chemodenervation of cervical musculature using botulinum neurotoxin (BoNT) is established as the gold standard or treatment of choice for management of Cervical Dystonia (CD). The success of BoNT procedures is measured by improved symptomology while minimizing side effects and is dependent upon many factors including: clinical pattern recognition, identifying contributory muscles, BoNT dosage, and locating and safely injecting target muscles. In patients with CD, treatment of anterocollis (forward flexion of the neck) and anterocaput (anterocapitis) (forward flexion of the head) are inarguably challenging. The longus Colli (LoCol) and longus capitis (LoCap) muscles, two deep cervical spine and head flexor muscles, frequently contribute to these patterns. Localizing and safely injecting these muscles is particularly challenging owing to their deep location and the complex regional anatomy which includes critical neurovascular and other structures. Ultrasound (US) guidance provides direct visualization of the LoCol, LoCap, other cervical muscles and adjacent structures reducing the risks and side effects while improving the clinical outcome of BoNT for these conditions. The addition of electromyography (EMG) provides confirmation of muscle activity within the target muscle. Within this manuscript, we present a technical description of a novel US guided approach (combined with EMG) for BoNT injection into the LoCol and LoCap muscles for the management of anterocollis and anterocaput in patients with CD.