Mechanism of vocal cord paralysis in neurodegenerative diseases

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Rinsho Shinkeigaku 1998 Aug;38(8):711-8

[Myopathology of the intrinsic laryngeal muscles in neurodegenerative

diseases,

with reference to the mechanism of vocal cord paralysis]

[Article in Japanese]

Isozaki E, Hayashi M, Hayashida T, Oda M, Hirai S.

Department of Neurology, Tokyo Metropolitan Neurological Hospital.

To investigate the mechanism of the vocal cord abductor paralysis (VCAP) in

the

neurodegenerative diseases, the intrinsic laryngeal muscles (the

crycothyroid,

the interarytenoid, and the posterior crycoarytenoid muscles) from 41

autopsied

cases were histologically examined: 10 cases of amyotrophic lateral

sclerosis

(ALS), 10 of Parkinson's disease (PD), 9 of multiple system atrophy (MSA), 4

of

Machado-ph disease (MJD), 4 of progressive supranuclear palsy (PSP), 1

of

familial amyloidotic polyneuropathy (FAP), and 3 of cerebrovascular diseases

as

a control. According to the distribution of the neurogenic changes among

above-described three intrinsic laryngeal muscles, three forms were raised:

1.

The totally paralytic form showing that all the three muscles developed

neurogenic atrophy. This form includes ALS, MJD, and FAP. 2. The posterior

muscle-paralytic form showing that only the posterior crycoarytenoid muscle

was

selectively involved. This form includes MSA. 3. The nonparalytic form

showing

no morphological abnormalities in any of the intrinsic laryngeal muscles.

This

type includes PD and PSP. In this nonparalytic form, supranuclear mechanism

such

as pyramidal or extrapyramidal tract involvement may cause VCAP through the

increased laryngeal muscles tone. Considering that VCAP can be seen in any

of

the above-described forms, our results indicate that the mechanism of VCAP

is

different among the neurological disorders.

PMID: 9916515 [PubMed - indexed for MEDLINE]