Tongue mechanical characteristics and genioglossus muscle EMG in obstructive sleep apnoea patients.

The increased genioglossus muscle (GGm) activity seen in obstructive sleep apnoea syndrome (OSAS) may lead to increased fatigability or longer recovery time of the tongue. Maximal force, endurance, and recovery times of the tongue, electromyogram (EMG) absolute value, and EMG spectral analysis of the GGm obtained during submaximal contractions were compared in eight individuals without chronic snoring and eight OSAS patients. Endurance time values were not significantly different between the two groups (P = 0.40). Time to recovery of initial maximal force was significantly greater in the OSAS group (P = 0.01). Final EMG median frequency was significantly higher (P = 0.01) and the final low-frequency EMG component smaller in the OSAS patients (P = 0.02). Patients did not have changes in endurance time or fatigability but had longer recovery times and changes in spectral analysis variations. This functional investigation may be helpful in determining the presence of OSAS and the potential contribution of the tongue to pharyngeal obstruction.

Respiratory effects of combined truncal and abdominal support in patients with spinal cord injury.

OBJECTIVE: To determine whether a custom girdle, designed to provide truncal stability and abdominal support, will improve pulmonary function, enhance inspiratory muscle activity, and reduce the sensation of respiratory effort in patients with spinal cord injury (SCI). DESIGN: Pulmonary function, transdiaphragmatic pressure time product (PTP di ), twitch (Tw Pdi) and maximal transdiaphragmatic pressures (Pdi), and perception of respiratory effort (Borg Rating of Perceived Exertion score) were measured with and without an abdominal girdle in a seated position. SETTING: Rehabilitation hospital. PARTICIPANTS: Ten patients with posttrauma SCI (injury level, C5-T6). INTERVENTION: Application of the abdominal girdle. MAIN OUTCOME MEASURES: Borg score and measures of lung volumes, dynamic abdominal compliance, and Tw Pdi and maximal Pdi. RESULTS: Wearing of the girdle was associated with a lower Borg score (P = .002) and reduced functional residual capacity (P = .006) but increased inspiratory capacity (P = .02) and forced vital capacity (P = .02). Although there was a decrease in dynamic abdominal compliance (P < .001) and an increase in PTP di (P = .02), this was accompanied by an increase in both Tw Pdi (P = .02) and maximal Pdi (P = .03). CONCLUSIONS The custom girdle reduced the sensation of respiratory effort in patients with SCI by optimizing the operating lung volumes and decreasing abdominal compliance, which enhanced diaphragm performance.