The Impact of Videofluoroscopic Pulse Rate on Duration and Kinematic Measures in Infants and Adults with Feeding and Swallowing Disorders

This investigation assessed the impact of temporal resolution during a videofluoroscopic evaluation of swallowing (VFSS) on measures of duration and kinematics. Thirty adult and ten infant swallow studies, all acquired at 30 frames and 30 pulses per second, were obtained from a New Mexico hospital. All swallow studies were altered to simulate 15 and 5 pulses per second. Duration measures included pharyngeal response time, duration of upper esophageal sphincter (UES) opening, velopharyngeal closure duration and total swallow duration. Kinematic measures were assessed in adults only and included peak hyoid position and extent of UES opening during the swallow. Analysis of outcome measures was performed and compared across the three temporal resolutions (30, 15, and 5 pulses per second). For data points where normative values are available, we evaluated the impact of temporal resolution on clinical determination (i.e., did a change in pulse rate alter the clinical classification). Kinematic and duration measures were altered with changes in pulse rate and these changes increased as temporal resolution decreased. For outcome measures where normative values are available, accuracy of clinical determination decreased with decreased pulse rate. Temporal resolution impacts duration and kinematic measures. However, the direction of these changes is unpredictable, indicating sensitivity and specificity are both affected. Without a predictable impact, the use of lower pulse rates may alter clinical impressions and treatment recommendations yielding inappropriate treatment goals and treatment duration.