Clinical measurement of swallowing in health and in neurogenic dysphagia

We studied clinical features potentially related to dysphagia and threeindices from a timed test of swallowing--average volume per swallow (ml),average time (s) per swallow and swallowing capacity (ml/s)--in 181screened healthy adults and 30 patients with motor neurone disease (MND).In healthy adults, age, sex and height accounted for 44.3% and 55.6% of thevariance of log average volume per swallow and log swallowing capacity,respectively. Symptoms and signs were more prevalent in the MND group andwere associated with reduced swallowing capacity and reduced average volumeper swallow; repeatability studies on these two indices in both groupsshowed that the median difference between the mean of two recordings onsuccessive days and the mean of all recordings (6-15 over 3 days) was <5% (maximum third quartile 12.8%, indices expressed as percent predictedaccording to age and sex). Using this simple bedside test, swallowingfunction can be quantified on a ratio scale and expressed as percent ofthat predicted by age and sex; such information may improve the predictivevalue of clinical assessment and provides a practical way of monitoringchange in patients with dysphagia.