Cranial Nerve Deficits Predict Pharyngeal Phase Swallowing Impairment in Patients with Neurogenic Dysphagia: A Cross-Sectional Study

The examination of the cranial nerves (CN) provides an accurate analysis of facial-oral integrity, motility and sensitivity that is fundamental to understanding swallowing efficiency. The aim of this cross-sectional study is to verify whether the assessment of CN can provide information on the amount and location of pharyngeal residue and risk of aspiration in patients with neurogenic dysphagia. A total of 96 dysphagic patients have been enrolled. Pharyngeal residue was assessed by the Italian version of the Yale Pharyngeal Residue Severity Rating Scale (IT-YPRSRS) and presence of penetration/aspiration using the Penetration–Aspiration Scale (PAS) during Fiberoptic Endoscopic Evaluation of Swallowing (FEES), while CNs were evaluated using the I&I test. Logistic regression models were used to investigate causal associations; for each of the CN found to be significant, the optimal cut-off to best discriminate healthy patients from those with pathology was calculated. All statistical analyses were performed using R software with the significance level set at P < 0.05. Significant correlations were found between total scores on the I&I test and the PAS and IT-YPRSRS results. Impairment of CN VII was a sensitive and specific predictor of vallecular residue. Deficits of V CN and X CN were predictors of pyriform sinus residue. PAS scores were just below the statistical significance. Assessing CN can provide specific pathophysiological information about pharyngeal residue and risk of penetration/aspiration. These findings could help clinicians understand swallowing issues and early plan targeted interventions.