[When should tracheotomy be performed in bilateral vocal cord paralysis involving multiple system atrophy?]

Bilateral vocal cord paralysis caused by central nervous system dysfunction results from such diverse causes as cerebrovascular disorder and neurodegenerative disease. Otolaryngologists are often consulted about indications of tracheostomy for such cases, but if their recognition of causative disease is insufficient, it is difficult to judge indications of tracheostomy. We reviewed tracheostomy cases due to bilateral vocal cord paralysis caused by multiple system atrophy (MSA) and considered points to keep in mind in such cases.

We diagnosed 9 cases of vocal cord midline fixation due to central bilateral vocal cord paralysis caused by MSA and treated by tracheostomy. We reviewed clinical conditions and suitable time for tracheostomy because it presents a specific clinical course.

7 cases were MSA-P and 2 cases were MSA-C. Inspiratory stridor in awaking and dysphasia was aggravated at the almost same time in 7 cases.

Vocal cord abductor paralysis in MSA may cause sudden death, but when an otolaryngologist not familiar with this disease is asked for air way evaluation, it is possible to be diagnosed as no vocal cord paralysis because there is no an adductor disorder, so clinical course of MSA should be clarified more. In vocal cord midline fixation, it was expected that intervention by hypermyotony in the progress of Parkinsonism was a main factor, as was vocal cord abductor disorder due to a neurogenic change in the posterior cricoarytenoid muscle in MSA. The aggravation of dysphasia is an important index in judging the indication of tracheostomy.