Swallow Reaction Time in Healthy Adults

Area of Science:

• Swallowing physiology
• Clinical assessment of dysphagia

Background:

• Swallow onset is typically defined by bolus location.
• Quantifying swallow events with swallow reaction time (SRT) can enhance swallow assessment.
• Establishing normative SRT values in large, healthy populations using validated methods is limited.

Purpose of the Study:

• To investigate SRT in a large cohort of healthy adults.
• To examine the influence of demographic factors (age, sex) and bolus characteristics (viscosity, volume) on SRT.
• To utilize the Modified Barium Swallow Impairment Profile (MBSImP) approach for standardized SRT measurement.

Main Methods:

• Analysis of archival videofluoroscopic swallow studies (VFSS) from 195 healthy adults (aged 21-89).
• Measurement of SRT across seven standardized swallow tasks with varying bolus viscosities (thin to extremely thick liquids) and a solid bolus.
• Application of generalized estimating equation models to assess demographic and bolus effects on SRT.

Main Results:

• Significant variability in SRT was observed across all swallow tasks in healthy adults.
• Bolus viscosity was the only significant factor influencing SRT.
• Increased bolus viscosity correlated with a longer SRT.

Conclusions:

• Swallow reaction time (SRT) exhibits considerable variability in healthy adults across different bolus types.
• Higher viscosities of liquids result in longer SRTs, which should be recognized as normal variations.
• This research provides normative SRT data based on a widely used VFSS protocol, offering valuable reference points for clinical practice.