Dysphagia or Normal Aging? 6 Indicators to Distinguish the Difference

The elderly population is a large and growing part of the US population, with 40 million individuals over the age of 65.1 All these aging individuals experience physiological changes, including in their swallow function. With such a large potential patient population, we must know how to tell the difference between the normal aging swallow (presbyphagia) and swallowing impairment.

Changes from Normal Aging

Many changes to swallow function come with healthy aging and do not result in dysphagia. Of course, elderly people experience dysphagia – the prevalence in community-dwelling elderly appears to be 15%.10 These numbers increase in those with other disabilities like stroke, COPD, Parkinson’s disease, and dementia. Aging predisposes individuals for difficulty swallowing, particularly those with low muscle mass or nutritional compromise at baseline.11

To distinguish between healthy aging and the onset of dysphagia, we should first understand swallow changes as a result of aging:

Laryngeal Penetration

Shallow laryngeal penetration – material enters the laryngeal vestibule but does not reach the vocal folds –  is a normal finding in all age groups. It’s more frequent at both ends of the lifespan: in infancy and in the elderly. Thus, older adults will often have shallow laryngeal penetration, particularly with liquid boluses.2-7

Slowed Swallow Response

Studies with healthy older adults show the swallow response changing with age. The swallow response has a later onset, is slower, and lasts longer across bolus types. The result is longer pharyngeal dwell times (e.g. food or liquid reaching the valleculae or even the pyriform sinuses before the swallow response triggers). This should not be confused with an impaired swallow response. 4,5,8,12,15

Reduced Sensation

Many elderly men and women report changes in taste, specifically in taste acuity. With age, we lose taste bud density and, perhaps more importantly, retronasal olfaction. The olfactory sensations – received as we chew and manipulate food – augment our perception of taste. Reduced olfaction causes taste loss, which can contribute to dehydration, reduced variety in diet, and weight loss.14

Indicators of Dysphagia

Dysphagia clinicians face the dilemma of distinguishing between these normal changes in swallowing and actual dysfunction. The following concepts may help indicate dysphagia:

Consistency

Normal penetration (and even aspiration) occurs inconsistently. For example, the patient who demonstrates laryngeal penetration on all thin liquid swallows is more likely to have dysphagia.

Depth

Normal laryngeal penetration is typically shallow. Penetration that reaches the level of the vocal folds is an irregular finding and should be identified as dysphagia.

Clearance

Normal laryngeal penetration is cleared spontaneously. Material that pools in the larynx and is not cleared is more likely to be aspirated. This swallow should be considered disordered.

We must be careful not to over-diagnose dysphagia in aging individuals. At the same time, we must be vigilant to identify and treat actual swallow impairments. As Betty Davis once famously said, “Old age is no place for sissies.”

References
  1.  http://www.census.gov/2010census/data/
  2. Allen, J., et al, “Prevalence of penetration and aspiration on videofluoroscopy in normal individuals without dysphagia”, Otolaryngol Head Neck Surg, 142(2), 208-13, 2010.
  3. Butler, S., et al, “Penetration and aspiration in healthy older adults as assessed during endoscopic evaluation of swallowing”, Annals of Otology Rhinology and Laryngology, 118)3), 190-98, 2009.
  4. Butler, S., et al, “Flexible endoscopic evaluation of swallowing in healthy young and older adults”, Annals Otology, Rhinology Laryngology, 118(2) , 99-106, 2009
  5. Butler, S., et al, “Factors influencing bolus dwell times in healthy older adults assessed endoscopically” Laryngoscope, 121(2), 2011.
  6. Butler, S., et al, “Effects of liquid type, delivery method, and bolus volume on penetration-aspiration scores in healthy older adults during flexible endoscopic evaluation of swallowing”, Ann Otol Rhinol Laryngol, 120(5), 288-95, 2011
  7. Daggett, A., et al “Laryngeal Penetration During Deglutition in Normal Subjects of Various Ages”, Dysphagia, 21(4), 270-74, 2006.
  8. Hiss, S., et al, “Effects of age, gender, bolus volume, and trial on swallow apnea and swallow/respiratory phase relationships of normal adults”, Dysphagia, 16(2), 128-35, 2001.
  9. Hiss, S., et al, “Effects of age, gender, bolus volume, bolus viscosity, and gestation on swallowing apnea onset relative to lingual bolus propulsion onset in normal adults”, Jnl Speech, Language Hearing Research, 47(3), 572-83, 2004.
  10. Madhavanm, A., et al, “Prevalence and risk factors for dysphagia in the community dwelling elderly: A systematic review”, J Nutr Health Aging, 20(8), 806-15, 2016.
  11. Maeda, K., and Akagi, J.,” “Cognitive impairment is independently associated with definitive and possible sarcopenia in hospitalized older adults: The prevalence and impact of comorbidities”, Geriatr Gerontol Int, June, 2016.
  12. Martin-Harris, B., et al, “Delayed initiation of the pharyngeal swallow: Normal variability in adult swallows”, Jnl Speech Language Hearing Research, 50(3), 585-94, 2007.
  13. Stephen, J., et al, “Bolus location at the initiation of the pharyngeal stage of swallowing in healthy older adults”, Dysphagia, 20(4), 266-72, 2005.
  14. Syed, Q., et al, “The impact of aging and medical status on dysgeusia”, Am J Med, 129(7), 2016.