Cough reflex attenuation and swallowing dysfunction in sub-acute post-stroke patients: prevalence, risk factors, and clinical outcome.

BACKGROUND: Cough and swallowing impairments in post-stroke patients (PSP) have been associated with increased risk for respiratory complications. AIMS: To assess the prevalence of alterations in protective cough responses in subacute PSP and its association with oropharyngeal dysphagia (OD), clinical, and neurotopographic stroke factors and clinical outcomes. METHODS: Three months after stroke, the cough reflex test (CRT) was performed by nebulizing incremental citric acid concentrations (7.8-1000 mmol L-1 ) to determine the concentration that elicited two and five coughs; OD was assessed by the volume-viscosity swallow test. Clinical and neurotopographic stroke risk factors and complications (readmissions, respiratory infections, institutionalization, and mortality) were recorded from 3 to 12 months post-stroke. RESULTS: We included 225 PSP. Prevalence of impaired CRT was 5.8%, that of OD was 40.4% (20.4% with impaired safety of swallow), and of both impairments was, 1.8%. No specific risk factors associated with impaired CRT were found; however, hemorrhagic, wide circulation infarction (TACI), and brainstem strokes delayed the cough response. OD was associated with age, TACI and poor functional and nutritional status. Outcome of PSPs was unaffected by impaired CRT but OD and impaired safety of swallow increased institutionalization, respiratory infections, and mortality with the poorest outcome for those with both impairments. CONCLUSIONS: Prevalence of subacute post-stroke OD and swallow safety impairments was much higher than CRT attenuation, and risk factors strongly differed suggesting that the swallow response receives a stronger cortical control than the cough reflex. OD has a greater impact on PSP clinical outcome than impaired cough, the poorest prognosis being for patients with both airway protective dysfunctions.

Effect of bolus volume on proximal esophageal contractions of patients with Chagas' disease and patients with idiopathic achalasia.

Chagas' disease and idiopathic achalasia patients have similar impairment of distal esophageal motility. In Chagas' disease, the contractions occurring in the distal esophageal body are similar after wet or dry swallows. Our aim in this investigation was to evaluate the effect of wet swallows and dry swallows on proximal esophageal contractions of patients with Chagas' disease and with idiopathic achalasia. We studied 49 patients with Chagas' disease, 25 patients with idiopathic achalasia, and 33 normal volunteers. We recorded by the manometric method with continuous water perfusion the pharyngeal contractions 1 cm above the upper esophageal sphincter and the proximal esophageal contractions 5 cm from the pharyngeal recording point. Each subject performed in duplicate swallows of 3-mL and 6-mL boluses of water and dry swallows. We measured the time between the onset of pharyngeal contractions and the onset of proximal esophageal contractions (pharyngeal-esophageal time [PET]), and the amplitude, duration, and area under the curve (AUC) of proximal esophageal contractions. Patients with Chagas' disease and with achalasia had longer PET, lower esophageal proximal contraction amplitude, and lower AUC than controls (P≤ 0.02). In Chagas' disease, wet swallows caused shorter PET, higher amplitude, and higher AUC than dry swallows (P≤ 0.03).There was no difference between swallows of 3- or 6-mL boluses. There was no difference between patients with Chagas' disease and with idiopathic achalasia. We conclude that patients with Chagas' disease and with idiopathic achalasia have a delay in the proximal esophageal response and lower amplitude of the proximal esophageal contractions.