Faculty Collaboration Database

Histology of nerves and muscles in adductor spasmodic dysphonia. Ann Otol Rhinol Laryngol 2003 Apr;112(4):334-41

Date

05/07/2003

Pubmed ID

12731628

DOI

10.1177/000348940311200407

Scopus ID

2-s2.0-0037387455 (requires institutional sign-in at Scopus site)   16 Citations

Abstract

To elucidate the etiology and pathophysiology of spasmodic dysphonia, we examined the adductor branch of the recurrent laryngeal nerve and the lateral cricoarytenoid muscle from 9 consecutive patients with this disorder who were previously treated with botulinum toxin. Histologic examination revealed average muscle fiber diameters ranging from 21 to 57 microm. Botulinum toxin treatment-related muscle atrophy was observed up to 5 months after injection. Endomysial fibrosis was present in all samples. Histochemical analysis in 8 patients revealed type 2 fiber predominance in 7 patients and fiber type grouping in 2. Type-specific muscle fiber size changes were not present. Nerve samples were examined in plastic sections. In 8 patients the nerves contained homogeneous, large-diameter myelinated nerve fibers and sparse small fibers. One patient had a relatively increased proportion of small myelinated nerve fibers. Overall, the nerve fiber diameter was slightly larger in patients than in controls. These findings may implicate the central nervous system in the pathophysiology of adductor spasmodic dysphonia.

Author List

Chhetri DK, Blumin JH, Vinters HV, Berke GS

Author

Joel H. Blumin MD Chief, Professor in the Otolaryngology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adult
Aged
Anti-Dyskinesia Agents
Biopsy
Botulinum Toxins
Electromyography
Female
Humans
Injections, Intramuscular
Laryngeal Muscles
Laryngeal Nerves
Male
Middle Aged
Motor Neurons
Voice Disorders