title: Laryngo-upper esophageal sphincter contractile reflex in humans deteriorates with age.
abstract: OBJECTIVE
  Recent studies have shown the existence of several reflex connections between the aerodigestive and upper gastrointestinal tracts. Our aim was to study the effect of laryngeal stimulation on upper esophageal sphincter (UES) pressure and to determine the reproducibility of this effect.
  
  
  METHODS
  We studied 14 young and 10 elderly healthy nonsmoker volunteers and 7 patients with UES dysphagia using a concurrent manometric and video endoscopic technique. Three levels of laryngeal air stimulation were studied: 6 mm Hg/50 ms, 10 mm Hg/50 ms, and 6 mm Hg/2 s. Ten young subjects were studied twice.
  
  
  RESULTS
  For 6-mm Hg/2-s and 6-mm Hg/50-ms duration stimuli, the frequency of UES response to air stimulation as evidenced by mucosal deflection (response/deflection ratio) in the elderly volunteers was significantly lower compared with that of young subjects (P < 0.05). The response/deflection ratio of the 6-mm Hg/2-s stimulus was significantly higher than those induced by stimuli of shorter duration (P < 0.01). Poststimulation UES pressure was significantly higher than prestimulation pressure (P < 0.05) in both groups. The magnitude of the increase in poststimulation UES pressure in the elderly volunteers was similar to that of the young subjects. Findings were similar in repeated studies. Four of 7 dysphagic patients exhibited an abnormal response.
  
  
  CONCLUSIONS
  Afferent signals originating from the larynx reproducibly induce contraction of the UES: the laryngo-UES contractile reflex. This reflex is elicited most reliably by 6-mm Hg/2-s air stimulation. Frequency elicitation of this reflex decreases significantly with age while the magnitude of change in UES pressure remains unchanged, indicating a deleterious effect of aging on the afferent arm of this reflex. This reflex is altered in some dysphagic patients.
authors.affiliation: Medical College of Wisconsin Dysphagia Institute, Division of Gastroenterology and Hepatology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: Osamu
authors.initials: O
authors.lastname: Kawamura
authors.forename: Caryn
authors.initials: C
authors.lastname: Easterling
authors.forename: Muhammad
authors.initials: M
authors.lastname: Aslam
authors.forename: Tanya
authors.initials: T
authors.lastname: Rittmann
authors.forename: Candy
authors.initials: C
authors.lastname: Hofmann
authors.forename: Reza
authors.initials: R
authors.lastname: Shaker
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D003680:Deglutition Disorders / Q000503:physiopathology; D004068:Digestive System Physiological Phenomena; D004943:Esophagogastric Junction / Q000502:physiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007830:Larynx / Q000502:physiology / Q000503:physiopathology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D012018:Reflex / Q000502:physiology; D012021:Reflex, Abnormal / Q000502:physiology*; D015203:Reproducibility of Results; D012143:Respiratory Physiological Phenomena