Acoustic analysis of swallowing sounds: a new technique for assessing dysphagia.
OBJECTIVE
To perform acoustic analysis of swallowing sounds, using a microphone and a notebook computer system, in healthy subjects and patients with dysphagia affected by neurological diseases, testing the positive/negative predictive value of a pathological pattern of swallowing sounds for penetration/aspiration.


METHODS
Diagnostic test study, prospective, not blinded, with the penetration/aspiration evaluated by fibreoptic endoscopy of swallowing as criterion standard.


METHODS
Data from a previously recorded database of normal swallowing sounds for 60 healthy subjects according to gender, age, and bolus consistency was compared with those of 15 patients with dysphagia from a university hospital referral centre who were affected by various neurological diseases.


METHODS
Mean duration of the swallowing sounds and post-swallowing apnoea were recorded. Penetration/aspiration was verified by fibreoptic endoscopy of swallowing in all patients with dysphagia.


RESULTS
The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between patients with dysphagia and healthy patients. We also described patterns of swallowing sounds and tested the negative/positive predictive values of post-swallowing apnoea for penetration/aspiration verified by fibreoptic endoscopy of swallowing (sensitivity 0.67 (95% confidence interval 0.24-0.94); specificity 1.00 (95% confidence interval 0.56-1.00)).


CONCLUSIONS
The proposed technique for recording and measuring swallowing sounds could be incorporated into the bedside evaluation, but it should not replace the use of more diagnostic and valuable measures.
Santamato
Andrea
A
Department of Physical Medicine and Rehabilitation, University of Foggia, Foggia, Italy.
Panza
Francesco
F
Solfrizzi
Vincenzo
V
Russo
Anna
A
Frisardi
Vincenza
V
Megna
Marisa
M
Ranieri
Maurizio
M
Fiore
Pietro
P
D000162:Acoustics; D000328:Adult; D000368:Aged; D001314:Auscultation / Q000379:methods*; D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D004724:Endoscopy; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D053120:Respiratory Aspiration / Q000175:diagnosis / Q000209:etiology; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D020521:Stroke / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology