Description of laryngeal response patterns during the MI-E protocol (n=40)
| Glottic level | Supraglottic level | Tongue base and hypopharyngeal level | |||
|---|---|---|---|---|---|
| Subjects (N=20) | True vocal folds (TVF) | Aryepiglottic folds (AEF) | Epiglottis (EG) | Base of the tongue (BT) | Hypopharynx (HP) |
| Healthy (n=20) | Adequate control* in all | Adequate control† in all | Retroflex movement in 8/20 | Backward in 4/20 | Constriction in 12/20 of varying degrees |
| ALS without bulbar symptoms (n=6) | Adequate control* in all | Adequate control† in all | Retroflex movement in 1/6 | Backward in all | Constriction in all of varying degrees |
| Progressive bulbar ALS (n=7) | Adequate control* in all | Adduction in insufflation in all | Retroflex movement+‘floppy’ in 1/7 | Backward in 5/7 | Constriction in all, and very narrow in 4/7 |
| Pseudobulbar ALS (n=7) | Inadequate control§ in insufflation; in 3/7and in 1/7 in exsufflation | Adduction in insufflation in all (but in 4/7, only at higher pressures: ≥+40 cm H2O) | Retroflex movement in 2/7 | Backward in all | Constriction in all, and very narrow in 1/7 |
*Normal cough, that is, TVF abduction in insufflation, glottic closure when coughing and TVF abduction+sequential closures and/or narrowing in exsufflation.
†AEF follows the movements of the TVF.
§Very small TVF opening in insufflation or in exsufflation.
ALS, amyotrophic lateral sclerosis; MIE, mechanical insufflation–exsufflation.