Domenico Antonio Restivo

Laryngeal adductor breathing dystonia (LABD) is a rare form of focal, task-specific respiratory dystonia affecting the laryngeal muscles of unknown aetiology. Unlike classical laryngeal dystonia (spasmodic dysphonia), LABD is not primarily characterised by impaired speech, but rather by dysfunction of respiratory laryngeal control. The hallmark pathophysiological alteration consists of involuntary, action-induced adductor spasms of the laryngeal muscles during respiration, particularly during inspiration. LABD must be distinguished from inducible laryngeal obstruction (ILO), a broader, heterogeneous condition encompassing episodic, stimulus-triggered supraglottic or glottic closure, associated with asthma, reflux, or psychological triggers, that is generally not task-specific and lacks the neurological substrate characteristic of dystonia. In contrast, LABD is a persistent, effort-dependent, neurologically driven dystonia, demonstrable by paradoxical adductor spasms on fibreoptic laryngoscopy during normal inspiration and confirmed electromyographically by paradoxical thyroarytenoid muscle activation instead of the expected inspiratory relaxation. Traditional treatments, including respiratory retraining, speech therapy, biofeedback, psychotherapy, benzodiazepines, dopamine-blocking agents, and anticholinergic drugs, have proved largely ineffective. Tracheostomy may be required in cases of severe respiratory compromise. Botulinum toxin type A (BoNT/A) injections have been reported to successfully reduce inspiratory stridor in selected patients. Here, we present three cases of LABD displaying distinct phenotypes, in which typical features were associated with involvement of extra-laryngeal cranial districts, further expanding the known phenotypic spectrum of this condition.

The efficacy of botulinum neurotoxin (BoNT) is strongly dependent on its accurate delivery to hyperactive muscles and, ideally, to motor endplate regions. Although guidance techniques such as electromyography (EMG) and ultrasound (US) improve injection precision, each technique provides only partial information—either functional or anatomical. Integrating these techniques could enhance targeting accuracy, optimize dose distribution, and reduce off-target effects. A structured PubMed search was performed using terms related to BoNT, spasticity/dystonia, EMG, and US. Filters included clinical trials, randomized controlled trials, meta-analyses and reviews published within the last decade. Fifty-nine studies met the inclusion criteria. The publications were predominantly in neuroscience and rehabilitation journals. Only 17 studies reported combined EMG–US guidance. These focused mainly on stroke and cervical dystonia. While EMG-US integration is a promising strategy, we emphasize the added value of EMG guidance for US approaches, which is particularly important when treating complex neurological conditions involving complex, overlapping muscle activation patterns, or when targeting structures that are inaccessible to conventional imaging techniques. The EMG-US integrated approach is a promising strategy for optimizing BoNT therapy by combining structural visualization with real-time functional assessment. Despite its promising advantages in terms of accuracy and dose optimization, its clinical adoption is limited by a lack of high-quality evidence.

Dysphagia is a frequent and potentially life-threatening complication in patients with neurological disorders. Swallowing is a complex neurophysiological mechanism regulated by a widespread network of central nervous system regions. The control of swallowing functions requires the integrity of the central pattern generator located in the brainstem, the sensorimotor cortex, the basal ganglia, and the cerebellum, but also peripheral nerves and swallowing muscles. Neurological diseases affecting either central or peripheral components of this system commonly result in dysphagia. Despite its clinical relevance, the management of neurogenic dysphagia remains challenging. While rehabilitative strategies such as swallowing therapy currently represent the main treatment option, emerging evidence suggests that non-invasive central and peripheral neuromodulation techniques may provide adjunctive beneficial effects. Further research is warranted to better define their efficacy, optimal protocols, and long-term outcomes.