taVNS in Infants Severe Dysphagia

Swallowing mechanics will be assessed using the Baby Videofluoroscopic Swallow Study Impairment Profile, a standardized scoring tool used to evaluate physiologic components of infant swallowing during videofluoroscopic swallow study. Scores will be compared from pre-treatment to post-treatment to determine change in swallowing impairment. Lower scores indicate less impairment.

Airway protection during swallowing will be assessed using the Penetration-Aspiration Scale from videofluoroscopic swallow study recordings. Scores describe the depth of airway invasion and the infant's response to material entering the airway. Scores will be compared from pre-treatment to post-treatment. Lower scores indicate better airway protection.

Feeding skills will be assessed using the Early Feeding Skills Assessment, a standardized clinical assessment used to evaluate infant feeding readiness, oral feeding skills, physiologic stability, and feeding tolerance. Scores will be compared from pre-treatment to post-treatment to evaluate change in functional feeding performance. Higher scores indicate more mature or more effective feeding skills.

Sucking pressures will be measured. Values will be compared from pre-treatment to post-treatment to evaluate change in sucking mechanics.

Oral feeding volume will be measured as the amount of prescribed feeding volume taken orally. Oral intake volume will be compared from pre-treatment to post-treatment to determine change in functional oral feeding ability. Greater oral intake volume indicates improved feeding performance.

Safety will be assessed by recording the number of bradycardia events occurring during intervention sessions. Bradycardia will be defined as heart rate less than 80 beats per minute for 5 seconds or longer during a feed. Events will be recorded per feeding session.

Safety will be assessed by recording the number of oxygen desaturation events occurring during intervention sessions. Oxygen desaturation will be defined as oxygen saturation less than 80% for 5 seconds or longer during a feed. Events will be recorded per feeding session.

Safety will be assessed by recording the number of coughing or choking episodes occurring during intervention sessions. Events will be recorded per feeding session to monitor clinical signs of feeding intolerance or airway compromise.

Feasibility will be assessed by determining the number and percentage of enrolled infants who complete the full 3-week paired taVNS and oromotor training intervention. Completion will be defined as finishing the planned intervention period.

Feasibility will be assessed by recording the number and percentage of planned oromotor training sessions completed. Protocol adherence will be calculated as the number of completed sessions divided by the number of planned sessions.

Treatment tolerance will be assessed using an events-to-time ratio, calculated as the number of bradycardia and/or oxygen desaturation events occurring during each 30-minute oromotor training session. A lower event rate indicates better treatment tolerance.