The Downside of Botulinum Injections for Anterocollis: A Case Series and a Review of the Literature

Objectives This is a case series and a review of the literature of therapeutic outcomes of botulinum toxin (BT) injections for anterocollis. Methods Data collected included gender, age, age at onset, muscles targeted, and doses injected. Routine forms were filled out during each visit: Patient Global Impression of Change, Clinician Global Impression of Severity, Tsui scale. The effect duration and side effects (SEs) of the previous treatment were noted. Results We described 4 patients (3 men, 13 visits) with anterocollis, as primary postural abnormality of the neck, emphasizing the therapeutic response to BT injection. Mean age at onset was 75.3 ± 7.0 years, age at first injection was 80.7 ± 3.5 years. The mean total dose per treatment was 290.0 ± 95.6 units. Patient Global Impression of Change with any grade of favorable effect was reported in 27.3% of the treatments. In objective assessment, Global Impression of Severity and Tsui scores did not show a consistent tendency of improvement. Neck weakness was prevalent in 18.2% of the visits of the anterocollis group while no other SEs were noted. We found 15 articles describing experience with BT for anterocollis in 67 patients (19 in deep and 48 in superficial neck muscles). Conclusions This case series describes the poor outcome of BT treatment for anterocollis, with low efficacy and bothersome SE. Levator scapulae injection for anterocollis is not effective and is highly associated with head drop and should perhaps be abandoned. Injection to the longus colli might give some benefit in non-responders.