Fiberoptic laryngoscopic neurological examination of amyotrophic lateral sclerosis patients with bulbar symptoms

Bulbar symptoms in amyotrophic lateral sclerosis (ALS) are variable, reflecting bulbar and pseudobulbar palsy. The current study sought to characterize the pharyngeal findings in ALS using a fiberoptic laryngoscope and compare them with the findings of general neurological examination. We enrolled ALS patients with bulbar symptoms who were admitted between 2014 and 2020. All participants were evaluated on salivary status, velopharyngeal movement during speech and swallowing, pharyngeal constriction, and vocal cord movement using fiberoptic laryngoscopy. The laryngoscopic findings were compared with general neurological examination results. A total of 50 patients (31 men; median age: 69 years) were enrolled. Salivary residue in the hypopharynx was the most common abnormal finding on laryngoscopy (40 patients; 80%). Twenty-three patients (46%) exhibited velopharyngeal insufficiency, 18 of which exhibited good velopharyngeal closure in swallowing and poor velopharyngeal closure in speech. Thus, these patients presented speech-swallow dissociation (SSD) in velopharyngeal closure. Five patients (10%) exhibited unilateral weakness of the pharyngeal constrictor muscles in phonation. Compared with general neurological examinations, emotional incontinence was more frequent in patients who presented with SSD in velopharyngeal movement, compared with those who did not. None of the five patients with unilateral weakness of pharyngeal constriction showed curtain movement on examination via the mouth. The specific findings of laryngoscopy in ALS patients, such as SSD in velopharyngeal closure and laterality in pharyngeal constriction, could not be evaluated by general neurological examination via the mouth.