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Is the External Laryngeal Nerve an Exclusively Motor Nerve? The Cricothyroid Connection Branch
Author(s) -
Maranillo Eva,
León Xavier,
Quer Miquel,
Orús César,
Sañudo Jose Ramón
Publication year - 2003
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1097/00005537-200303000-00024
Subject(s) - anatomy , recurrent laryngeal nerve , medicine , larynx , subglottis , superior laryngeal nerve , joint capsule , sensory system , biology , glottis , neuroscience , thyroid
Objectives To obtain an accurate morphological description of the nerve that provides communication between the external laryngeal nerve and the recurrent laryngeal nerve in a large sample of human larynges. Study Design Morphological study of human larynges. Methods Microdissection of 103 human larynges obtained from necropsies was performed. Both the external laryngeal nerve and the recurrent laryngeal nerve were identified and dissected. The existence of a communication between the two nerves was evaluated. Results A neural communication between the external laryngeal nerve and the recurrent laryngeal nerve was found in 85% of the larynges studied (bilaterally in 44% and unilaterally in 41%). Two patterns of communication (with single or double branches) were found. The communication between the nerves can appear at different levels, giving off collateral branches to the cricothyroid muscle (23%), the cricothyroid joint capsule (49%), and the subglottic mucosa (50%). Conclusions The nerve supply of the human larynx is more complex than classically considered. Our study does not support the classic neuroanatomical belief that the external laryngeal nerve is purely a motor nerve to the cricothyroid muscle. Our results reveal that it carries sensory and motor fibers on to other muscles (thyroarytenoid) or regions (subglottis mucosa and cricothyroid joint), as has been demonstrated in experimental studies in cats and dogs.