Laryngeal dysfunction in dysarthric speakers following severe closed-head injury.

The laryngeal function of 19 severely closed head-injured subjects with a perceptible dysarthria was assessed using electrolaryngography and a computerized airflow/air pressure analysis system (Aerophone II). Variables measured included parameters of the Lx waveform (Fo, duty cycle and closing time) as well as aerodynamic parameters such as subglottal pressure, glottal resistance, average phonatory sound pressure level, phonatory flow rate and ad/abduction rate. Values were compared to those recorded from a non-neurologically impaired control group matched for age and sex, and correlated with the findings of a perceptual speech analysis. The findings are discussed in relation to the effects of a severe closed-head injury on laryngeal function. The clinical implications of the findings for the assessment and treatment of vocal dysfunction in head-injured subjects are also discussed.