Methods for assessing swallowing motor function

Abstract

The present invention relates to methods for assessing swallowing motor function in a subject. The methods rely on obtaining intraluminal impedance and pressure measurements from the pharynx and / or esophagus of the subject during clearance of a bolus from the mouth and / or throat of the subject. The intraluminal impedance and pressure measurements are combined to derive a value for one or more pressure-flow variables in the pharynx and / or esophagus of the subject. The value of the one or more pressure-flow variables is compared to a predetermined pharyngeal and / or esophageal reference value for the one or more pressure-flow variables in order to provide an assessment of swallowing motor function in the subject. The intraluminal impedance and pressure measurements can also be combined to generate a swallow risk index for the subject or to generate an obstructive risk index for the subject based on a combination of a value of more than one pressure-flow variable in the pharynx and / or esophagus of the subject. In this way, swallowing motor function in the subject can be assessed by comparing the swallow risk index or obstructive risk index for the subject to a predetermined reference swallow index or predetermined reference obstructive index, respectively. Products which make use of these methods are also encompassed by the present invention.

Description

PRIORITY CLAIM[0001]This international patent application claims priority to Australian provisional patent application 2010904104 filed on 13 Sep. 2010, and to Australian provisional patent application 2011902359 filed on 16 Jun. 2011, the contents of which are herein incorporated by reference.FIELD OF THE INVENTION[0002]The present invention relates generally to methods for assessing pharyngeal and / or esophageal motor function in a subject during swallowing. The methods may be used to identify ineffective swallowing in the subject, including ineffective swallowing due to an obstruction, and may further be used to determine risk of aspiration in the subject.BACKGROUND OF THE INVENTION[0003]Swallowing is a complex process which involves a number of interdependent and coordinated phases. Generally, these include the preparatory, oral, pharyngeal and esophageal phases indicative of the anatomic regions traversed by a swallowed food and / or liquid bolus. During the preparatory phase, a f...

AI Technical Summary

Benefits of technology

The present invention provides a method for assessing swallowing motor function in a subject by combining and analyzing intraluminal impedance measurements and pressure measurements obtained from the pharynx and / or esophagus of the subject during swallowing. This method can provide valuable markers for assessing swallowing motor function and can also identify ineffective swallowing and risk of aspiration in the subject. The method can be used to predict the occurrence of dysphagia in the subject following therapy or surgery.

Problems solved by technology

When motor function is compromised, difficulty in swallowing (dysphagia) arises and an ineffective swallow ensues.

In addition, radiotherapy and chemotherapy associated with cancer treatment tends to weaken the muscles and degrade the nerves associated with the physiology and nervous innervation of the swallow reflex.

Dysphagia is often accompanied by aspiration due to ineffective airway protection during oropharyngeal swallowing.

Furthermore, aspiration can lead to recurrent pneumonia, progressive lung disease, and respiratory disability.

Therefore aspiration is a serious condition which can, if undetected, result in severe complications and potentially death.

Accordingly, dysphagia and pulmonary aspiration represent significant clinical, social, and economic costs and issues.

This hinders the provision of adequate nutrition, affecting growth and development leading to significant parental anxiety and family disruption.

Despite the significantly high prevalence of swallowing disorders and associated complications, the current methods for the assessment of swallowing and for the evaluation of direct aspiration are far from optimal.

Such disorders lead to ineffective pharyngeal bolus clearance and / or aspiration.

The use of manometry for assessment of aspiration risk has been very limited in routine clinical practice.

This is because manometric criteria alone have not been shown to accurately assess risk of aspiration and / or post-swallow bolus residue.

Although intraluminal impedance measurement has emerged in recent years as a technique that can be used to detect failed esophageal bolus transport, the application of impedance measurement to examine pharynx motor function has proven extremely challenging.

These factors cause impedance signals to be much more noisy in the pharynx than in the esophagus, so that attempts to optimize criteria that identify aberrant bolus flow events and residue have only been partially successful.

The limitations of fluoroscopy are however well known, the most important being prolonged exposure to radiation and the qualitative nature of the test, because it is not possible to derive robust numerical measures.

Accordingly it is not appropriate for patient screening.

As a result, subjects who are potentially at risk of aspiration are often not referred for fluoroscopy until they have deteriorated clinically and present with weight loss, eating difficulties, recurrent respiratory infections or aspiration pneumonia.

Whilst fluoroscopy can identify a point of narrowing of the lumen (such as a stricture, ring or web) that may be impeding normal flow of the bolus, in many patients the test fails to identify any obvious abnormality and these patient are often defined as suffering from non-obstructive dysphagia.

Furthermore, even if used for patient screening, there is clear evidence that fluoroscopy is poorly predictive of progression to aspiration pneumonia, and due to limits on investigation time, a normal fluoroscopy cannot entirely guarantee the absence of feed aspiration.

Indeed, at present there is no method that is sensitive for identification of subjects at high risk for deglutitive aspiration at a time when aspiration-associated complications might be prevented by intervention.

Furthermore, fluoroscopy-based parameters, such as pharyngeal residue, are relatively poor markers of aspiration.

Images