Laryngeal Dystonia Causing Inspiratory Stridor in Children with Cerebral Palsy

Abstract

OBJECTIVE To present three cases of inspiratory stridor caused by laryngeal dystonia (LD) in children with cerebral palsy (CP), one of whom is being treated by periodic botulinum toxin type A (BTX) injection into a vocalis muscle, thereby avoiding tracheostomy. STUDY DESIGN Case series. RESULTS AND CONCLUSIONS Laryngeal dystonia was diagnosed in three children with CP who presented with inspiratory stridor associated with generalized dystonia, all of whom were thought previously to have had laryngomalacia. The inspiratory stridor was severe enough in one patient that a tracheostomy was planned. In common with the movement disorder of generalized dystonia, the inspiratory stridor caused by LD was present in our patients when they were awake, worse when they were excited or agitated, diminished when they were awake and calm, and absent when they were asleep. Although there is overlap between the symptoms of LD and laryngomalacia (and other structural causes of upper airway obstruction) in children with CP, structural causes result in inspiratory stridor that is often persistent when patients are awake and relaxed or when they are asleep. Fiberoptic laryngoscopy in an awake patient with LD reveals vocal cord adduction in inspiration causing inspiratory stridor in association with generalized dystonia. Baclofen and gabapentin used together relieved the inspiratory stridor and improved the generalized dystonia of two patients, confirming the clinical diagnosis of LD, but for the last 2 years the third patient (the one with the most severe inspiratory stridor) also has required a periodic BTX injection into a vocalis muscle (the major vocal cord adductor) to relieve her inspiratory stridor, alternating the side of injection. Her mother considers this is a small price to pay to avoid tracheostomy. This is the first report of LD causing inspiratory stridor in patients with CP and the first reported use of BTX injection into a vocalis muscle for relief of inspiratory stridor due to LD in a child.

Awake upper airway obstruction in children with spastic quadriplegic cerebral palsy

“…However, some children with cerebral palsy have significant stridor and obstructive symptoms while awake, but without symptoms during sleep. This pattern of symptoms has been attributed to laryngeal dystonia in a small number of children with dystonic cerebral palsy 15 . It was also present in the case presented in detail earlier, but without evidence of vocal cord adduction in inspiration.…”

“…The term laryngomalacia is used imprecisely to describe inspiratory collapse of supraglottic tissues on inspiration in children with cerebral palsy 15 . This is different from laryngomalacia in infants, which is due at least in part to abnormally pliable laryngeal cartilage 18 .…”

“…In children with cerebral palsy laryngomalacia is attributed to reduction in tone of the soft tissues of the oropharynx in combination with pseudobulbar palsy. Forceful inspiration leads to collapse of these tissues into the airway, with resultant reduction in airway calibre and stridor 15 . This contributes in large part to the worsening of stridor when the child is awake and distressed.…”

Adductor laryngeal breathing dystonia in NBIA treated with botulinum toxin-A

“…Worley G et al . [6] described laryngeal dystonia causing inspiratory stridor in 3 cases of cerebral palsy. They presented with generalized dystonia with episodic inspiratory stridor.…”

“…[3] In literature, only a few case reports of ALBD has been described. ALBD has been reported in multiple system atrophy,[4] progressive supranuclear palsy,[5] cerebral palsy,[6] and Lubag syndrome. [7] It has not been described in NBIA.…”