Characterization of pharyngeal contractile integral using pharyngeal manometry in children

OBJECTIVES

Pharyngeal contractile integral (PhCI) is the product of mean pharyngeal contractile amplitude, length, and duration, and provides a single metric for the vigor of entire pharyngeal contraction. A major limitation in children is lack of characterization of PhCI on high-resolution pharyngeal manometry. We aimed to determine and compare the values of PhCI in children with the abnormal and normal videofluoroscopic study of swallow (VFSS).

METHODS

Children who underwent high-resolution pharyngeal and esophageal manometry (HRPM/HREM), as well as VFSS, were divided into two groups; "normal VFSS" and "abnormal VFSS" groups. PhCI was calculated from the pharyngo-esophageal manometry analysis software (MMS, v9.5, Laborie Medical Technologies), and compared in these two groups.

RESULTS

Of 67 children, 9 had abnormal VFSS (mean age 64 ± 50 months; 66.7% males), while 58 had normal VFSS (mean age 123 ± 55 months; 47% males). The mean PhCI in abnormal and normal VFSS groups was 82.00 ± 51.90 and 147.28 ± 53.89 mmHg.s.cm, respectively (p = 0.001). Subjects with abnormal VFSS were significantly younger than those with normal VFSS (p = 0.003). However, after adjusting for the VFSS result, age was no longer related to PhCI (p = 0.364). In subgroup analysis of children presenting with dysphagia, the mean PhCI in abnormal (9 subjects) and normal (36 subjects) VFSS groups was 82.00 ± 51.90 and 141.86 ± 50.39 mmHg.s.cm, respectively (p = 0.003).

CONCLUSIONS

PhCI was significantly lower in children with abnormal VFSS than in those with normal VFSS. We did not find a significant impact of age on PhCI in our pediatric populations.

The Evaluation of Benzodiazepine-induced Dysphagia Using High-resolution Manometry

We evaluated the pathophysiology of dysphagia considered to be induced by benzodiazepine using high-resolution manometry (HRM). A 53-year-old man with Parkinson disease had had dysphagia for over 3 months. He had been taking several benzodiazepines for more than four years. Two weeks after discontinuation of the benzodiazepines, HRM revealed increased pharyngeal contractility and residual pressure at the upper esophageal sphincter. A video-fluoroscopic swallowing study showed improved pharyngeal bolus passage. Benzodiazepine-induced dysphagia may be due to the muscle relaxant effects on the swallowing muscles and attenuation of the barrier function which prevents reflux from the esophagus into the pharynx.

Pharyngeal contraction secondary to its collapse in dogs with brachycephalic airway syndrome

Brachycephalic airway syndrome (BAS) is a common disease in certain "flat-faced" dog breeds. This syndrome includes stenotic nares, elongated and thickened soft palate, laryngeal collapse, and tracheal hypoplasia. Pharyngeal collapse is also commonly observed, but it is unclear if laryngopharynx motions are merely sequelae or actually contribute to BAS respiratory symptoms. Laryngopharynx motion was imaged using dynamic four-dimensional computed tomography (4D-CT) during spontaneous respiration in four dogs with different BAS types. Dynamic 4D-CT showed laryngopharynx motion in the following order during inspiration: pharyngeal collapse, contraction, and laryngospasm. We concluded that dynamic 4D-CT is a highly-detailed diagnostic approach for detecting laryngopharynx motion. Pharyngeal contraction during inspiration appears to contribute toward the worsening of clinical respiratory signs of BAS.