Respiratory muscle incoordination in stuttering speech

Area of Science:

• Speech-language pathology
• Respiratory physiology
• Neurology of speech disorders

Background:

• Stuttering is a complex speech disorder affecting fluency.
• The role of respiratory muscle function in stuttering requires further elucidation.
• Understanding respiratory control mechanisms is crucial for speech production.

Purpose of the Study:

• To investigate the coordination of respiratory muscles during stuttering.
• To determine the impact of respiratory muscle activity on subglottic pressure control.
• To differentiate respiratory patterns in individuals who stutter versus fluent speakers.

Main Methods:

• Measurement of esophageal, gastric, and transdiaphragmatic pressures.
• Calculation of subglottic pressure (Psg) and respiratory muscle contraction indices.
• Comparative analysis between severe stutterers and normal fluent speakers during speech tasks.

Main Results:

• Stutterers exhibited failure to control subglottic pressure (Psg) due to uncoordinated diaphragm, rib cage, and abdominal muscle contractions.
• Speech in stutterers was characterized by substantial and chaotic Psg variations, unlike the stable Psg in fluent speakers.
• Periods of fluency in stutterers were associated with improved Psg control.

Conclusions:

• Respiratory muscle incoordination is a significant factor in stuttering, impairing the control of pressure across the vocal cords.
• The findings suggest a potential link between respiratory dysregulation and stuttering severity.
• Further research is needed to determine if this respiratory abnormality is primary or secondary.