Case Series and Literature Review on Botulinum Toxin Efficacy in Axial Extensor Truncal Dystonia

Axial truncal dystonia can present as either flexion or extension, often with a tendency toward lateral movement. Flexion dystonia is more common and may represent a clinical spectrum associated with parkinsonism. In contrast, extensor trunk dystonia is less frequent and exhibits a diverse range of causes. In this paper, we reviewed the literature on axial extensor trunk dystonia. We identified 11 studies involving 49 patients, of which only 10 had idiopathic trunk dystonia. Treatment with botulinum neurotoxin A (BoNT/A) emerged as the most effective therapy; however, many studies did not provide detailed descriptions of the treatment (4/11) and follow-up periods were not specified or short term (up to one-two years). We present four new, well-documented patients with the idiopathic form of extensor trunk dystonia who were treated with BoNT/A with moderate to significant effect according to Global Clinical Impression scale (GCI) and Burke-Fahn-Marsden (BFM) dystonia scale. These cases include long-term follow-up for three patients, all without any adverse events. While the diagnostic process and treatment can be challenging, we recommend using BoNT/A with adjusted doses tailored to the appropriate muscle groups as a first-line treatment.