Comments on Selected Recent Dysphagia Literature

David W. Buchholz, MD and Stefanie Neumann, MA

Augmentation of Deglutitive Upper EsophagealSphincter Opening in the Elderly by ExerciseShaker R, Kern M, Bardan E, Taylor A, Stewart ET,Hoffmann RG, Arndorfer RC, Hofmann C, Bonnevier JAm J Physiol 272 (Gastrointest Liver Physiol 35):G1518–G1522, 1997

Shaker et al. studied 31 asymptomatic healthy elderlysubjects to test the hypothesis that an isotonic/isometricneck exercise aimed at strengthening the upper esopha-geal sphincter (UES) opening muscles would increaseUES deglutitive opening and be associated with de-creased pharyngeal outflow resistance. The authors notethat deglutitive UES opening is determined by a combi-nation of (a) relaxation and pliability of the sphincter and(b) distraction forces imparted on the sphincter by theUES opening muscles including geniohyoid, thyrohyoid,and digastric muscles. Among these factors associatedwith UES opening, only the contribution of the UESopening muscles is potentially amenable to noninvasivemanipulation such as exercise.

Nineteen subjects performed real exercise, and 12performed sham exercise. Real exercise consisted ofthree repetitive 1-min sustained head raisings in the su-pine position, interrupted by a 1-min rest period, andfollowed by 30 consecutive repetitions of head raisings.Subjects were instructed to raise their heads high enoughto be able to observe their toes without raising theirshoulders (which would exercise abdominal musclesrather than UES opening muscles). Sham exercise con-sisted of sustained and repetitive fist clinching. Subjectswere unsupervised as they exercised three times daily for6 weeks.

At the beginning and end of the 6-week interval,all subjects were studied by videofluorography, and 12real- plus six sham-exercise subjects underwent mea-surement of hypopharyngeal intrabolus pressure, pre-sumed to be directly correlated with pharyngeal outflowresistance. Significant increases were found in anterior

excursion of the larynx and maximum anteroposteriordiameter and cross-sectional area of the UES after realexercise versus sham exercise (p < 0.05). There was alsosignificant decrease in hypopharyngeal intrabolus pres-sure, presumably reflecting decreased pharyngeal out-flow resistance (p < 0.05). Shaker et al. point out that theexact muscles trained by exercise in this study were notdetermined, but electromyographic evidence from Jurell[1] suggests involvement of the mylohyoid, geniohyoid,and anterior digastric muscles. They note that the effectof this exercise program on swallowing in patients withpharyngeal dysphagia remains to be determined.

CommentsThe concept of treating oral/pharyngeal dysphagia bydecreasing pharyngeal outflow resistance (and presum-ably thereby enhancing pharyngeal clearance) is not new,as shown by the long history of cricopharyngeal myot-omy, an invasive procedure that has yet to achieve aclearly defined role in managing oral/pharyngeal dyspha-gia. More recently, attention has turned to other, lessinvasive approaches, some old and some new, includingUES dilatation, botulinum toxin injection, and now the‘‘Shaker exercise.’’

The exercise program studied by Shaker et al.holds promise, but it remains to be seen whether or not itwill be of functional benefit to patients. Encouragingresults regarding use of this exercise program in a smallgroup of patients with oral/pharyngeal dysphagia havebeen reported [2], but there were no controls, and someof the patients were relatively early in the course of acuteneurologic insults such as stroke that may have improvedspontaneously.

We hope that other questions about this exerciseprogram will also be answered. Is the regimen that theauthors employed optimal, or is it too much, too little, ormisguided and inefficient? Does the exercise need to becontinued indefinitely in some (if so, whom?) or all pa-tients, and will patients in the real world comply long-

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© Springer-Verlag New York Inc. 1999

term? Are there patients who would benefit most from acombined approach, such as dilatation or botulinumtoxin injection plus a maintenance program of exercise?We look forward to learning more.

References

1. Jurell KC: Spectral analysis to evaluate suprahyoid muscle in-volvement in neck exercise.Muscle Nerve 19:1224, 1996.

2. Easterling C, Kern M, Nitschke T, Grande B, Daniels S, CullenGM, Massey BT, Shaker R: Effect of a novel exercise on swal-low function and biomechanics in tube fed cervical dysphagiapatients: a preliminary report [abstract].Dysphagia 14:119,1999.

Grains or Veins: Is Enteral Nutrition Really BetterThan Parenteral Nutrition? A Look at the EvidenceLipman TOJ Parenter Enter Nutr 22:167–182, 1998

Lipman performed a literature review to evaluate the nullhypothesis that there is no difference between enteral andparenteral nutrition. Enteral nutrition is generally consid-ered better than parenteral nutrition in the following re-spects: (a) it is less expensive, (b) it is safer, (c) it is more‘‘physiologic,’’ (d) it promotes gastrointestinal tractfunction and integrity, (e) it prevents bacterial transloca-tion, and (f) it improves outcome. In reviewing the lit-erature, Lipman attempted to find evidence to supportthese contentions of superiority of enteral over parenteralnutrition.

For the most part he failed to find such evidence.The existing literature indicates that enteral nutrition isless expensive than parenteral nutrition, but otherwise,with the minor exception of probable reduced septicmorbidity in acute abdominal trauma, enteral nutritionhas not been shown to be superior to parenteral nutrition.

Lipman draws the following conclusions, basedon available evidence: (a) enteral nutrition is not saferthan parenteral nutrition, (b) enteral nutrition is not morephysiologic than parenteral nutrition, (c) enteral nutritioncompared with parenteral nutrition does not enhance hu-man intestinal function and integrity, (d) parenteral nu-trition does not promote bacterial translocation in hu-mans, and enteral nutrition does not prevent it, and (e)enteral nutrition is not associated with improved clinicaloutcome when compared with parenteral nutrition.

Lipman is careful to point out that his review ofthe literature failed (with noted exceptions) to disprovethe null hypothesis—that there is no difference betweenenteral and parenteral nutrition—but enteral nutritionmay be superior in at least certain respects. If so, thisremains to be demonstrated.

CommentsThis helpful review by Lipman is in synchrony withother recent literature (see below) comprising a wave ofrevisionism about tube feeding. Most of this literaturehas stimulated our awareness that feeding tubes may domore harm than good, but Lipman’s paper reminds usthat there is an alternative to tube feeding, namely par-enteral nutrition, in patients who require nonoral feeding,and parenteral nutrition may not be as undesirable analternative as many of us have long considered.

Audit of Percutaneous Endoscopic Gastrostomy inLong-Term Enteral Feeding in a Nursing HomeBourdel-Marchasson I, Dumas F, Pinganaud G, EmeriauJ-P, Decamps AInt J Qual Health Care 9:297–302, 1997

Bourdel-Marchasson et al. performed a retrospectivestudy of percutaneous endoscopic gastrostomy (PEG) ina 240-bed nursing home. A group of 58 patients withPEG was compared with a control group of 58 patients.PEG had been placed because of vegetative state in sixpatients, swallowing difficulties in 31, and anorexia in21. Patients in the control group had been considered fornutritional support, but no artificial nutrition had beenimplemented due to either refusal by the patient or fam-ily or decision by the staff. The groups were otherwisesimilar except that pressure ulcers were present beforePEG in 34 patients in the PEG group and in only sevenin the control group (p < 0.001).

Outcome measures included mortality, complica-tions (cutaneous, digestive, and pulmonary), and poorbehavioral tolerance of PEG. There was no significantdifference between the PEG and control groups in any ofthese measures. Pulmonary complications occurred in39% of the PEG group. Aspiration pneumonia was sig-nificantly associated with swallowing difficulties in bothgroups (p < 0.05). Eighty percent in the PEG group hadcutaneous complications around the insertion site includ-ing eight abscesses during the first week. Pressure ulcershealed in most of the patients with PEG, but new ulcersappeared in 25% of the PEG patients who were ulcer freeprior to PEG. Over 25% of the PEG patients attempted towithdraw the tube.

The authors conclude that indications for enteralnutrition should be carefully examined, with life expec-tancy at least 3 months and a better outcome with enteralnutrition expected.

CommentsAs with other studies regarding tube feeding, these find-ings are difficult to interpret because of the lack of a truly

114 D.W. Buchholz and S. Neumann: Recent Dysphagic Literature

comparable control group. Are patients who undergoPEG more predisposed or less predisposed to mortalityand cutaneous, digestive, and pulmonary complicationsthan patients who are considered for PEG but do notundergo it? The answer may be that some are more soand some are less so and that trying to apply data such asthese to clinical decision making is a guessing game.

We find it difficult to disagree with the authors’conclusions, but we remain uninformed, based on notonly their data but also the rest of the literature, as towhat are indications for enteral nutrition and what betteroutcome can be expected.

Tongue–Jaw Linkages in Human Feeding: A Prelimi-nary Videofluorographic StudyPalmer JB, Hiiemae KM, Liu JArch Oral Biol 42:429–441, 1997

In this study of normal feeding in humans, tongue andjaw movements were found to be linked, as in othermammals.

CommentsWe reference this study not so much because of its find-ing of tongue–jaw linkages in human feeding but be-

cause its methodology makes a larger point. Our under-standing of swallowing is derived largely from studiesconducted under extremely limited and artificial circum-stances, that is, videofluorographic swallowing studies(VFSS) that focus on narrow aspects of oral and pharyn-geal function under rigid protocols. In contrast, for anumber of years Palmer et al. have used videofluorog-raphy to look at normal feeding in an effort to betterunderstand the roles of the mouth, tongue, and jaw.

In the process, this work has painted a largerpicture of swallowing than the narrow view provided byroutine VFSS. It turns out that our normal, narrow viewvia VFSS is misleading in important ways. For example,the findings of Palmer et al. have shown that preswallowvallecular pooling is routine in healthy individuals andshould not be construed as a ‘‘delayed swallowing re-flex,’’ as was recently pointed out by Chi-Fishman andSonies [1]. We need to address more fully the discrep-ancies between swallowing during normal feeding, asshown by methodology such as that of Palmer et al., andour construct of swallowing as perceived through theslit-like window of VFSS.

Reference

1. Chi-Fishman G, Sonies BC: Normal, or abnormal—that is thequestion: pharyngeal delay for cookie swallow [abstract].Dys-phagia 14:120, 1999

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