Premium
Regional Genioglossus EMG Highlights Persistent Daytime Activation in OSA
Author(s) -
Vranish Jennifer,
Bailey E.Fiona
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.1013.7
Subject(s) - genioglossus , supine position , medicine , breathing , cardiology , motor unit recruitment , myosin , anatomy , electromyography , physical medicine and rehabilitation , anesthesia , chemistry , biochemistry
The genioglossus (GG) is an extrinsic muscle of the human tongue that plays a critical role in preserving airway patency. Recent research has identified regional differences in muscle fiber type and myosin heavy chain expression giving rise to the possibility that the anterior and posterior GG may fulfill distinct functions. Here, we recorded GG EMG activity in anterior and posterior regions of the muscle, across upright and supine, and in involuntary (CPG‐driven) and volitionally modulated breathing tasks in healthy adults and adults with OSA. Using this step‐wise approach we tested the hypothesis that respiratory CPG‐driven inputs preferentially drive the posterior muscle region and that voluntary (i.e., motor cortex) inputs drive activation in the more anterior region of the muscle. Our results show clear differences in the magnitude of GG EMG (% of maximum) between anterior and posterior muscle regions (7.95±0.57 vs. 11.10±0.99, respectively; P < 0.001), between upright and supine (8.63±0.73 vs. 10.42±0.90, respectively; P = 0.008) and between volitionally modulated and CPG driven breathing or deep breathing ( P < 0.001). Whereas an exclusively voluntary task results in greatest activation in the anterior tongue (P <0.001), volitionally modulated breathing tasks are associated with greatest activation in the posterior muscle (P <0.001). Preliminary findings indicate that whereas net drive to the GG is far greater in the OSA patient, the distribution of drive does not differ appreciably between the two groups. Our findings provide additional evidence that a nighttime breathing disorder impacts upon day‐time activation of a pharyngeal dilator muscle in a predictable fashion.