4 Examples Of The Latest Dysphagia Research
Swallowing disorders are hidden maladies, which severely affect an estimated 15 million Americans.1 These swallowing challenges typically interfere with nutritional intake which can lead to hospitalizations and life threatening outcomes such as aspiration pneumonia.2 While dysphagia topics have been studied for years, the disorder is still often poorly understood, under-diagnosed and, as a result, mistreated, even by experienced professionals.3 In an attempt to analyze and quantify the findings of some of the latest dysphagia research, four studies are overviewed below, focusing on areas of dysphagic treatment and therapy developments and how they may prove beneficial to health care professionals in the treatment of dysphagia.
Isometric Lingual Therapy
Dysphagia (defined within this context as difficulty eating and swallowing) is extremely common following a stroke and may occur in up to 65 percent of stroke patients.4,5,6 As previously stated, dysphagia has been associated with higher rates of respiratory complications and increased risk of aspiration pneumonia7,8, dehydration9 and nutritional compromise.10
To examine the effects of lingual exercise on swallowing recovery post-stroke, patients between the ages of 51 to 90 in a dysphagia clinic and tertiary care center were subjected to an eight-week isometric lingual exercise program, during which they compressed an air-filled bulb between the tongue and hard palette.
For measurement purposes, Isometric and swallowing lingual pressures, bolus flow parameters, diet, and a dysphagia-specific quality of life questionnaire were collected and analyzed. The study findings indicated that lingual exercise enables acute and chronic dysphagic stroke patients to increase lingual strength with associated improvements in swallowing pressures, airway protection, and lingual volume.10
Neuromuscular Electrical Stimulation (NMES)
Tiny electric shocks, delivered through Neuromuscular Electrical Stimulation (NMES), may help stroke victims to overcome or better adapt to swallowing difficulties. A recent study conducted at the University of Manchester examined whether stimulating nerves in the throat with small electrical jolts can positively stimulate areas of the brain damaged by stroke.11
Researchers inserted a small tube into the throats of 28 stroke patients, with half receiving mild electrical shocks and half receiving no current. The number of stimulated participants who had swallowing difficulties with liquids decreased from about two-thirds pre-treatment to about one-quarter post-treatment. There was no change in the group that received no shocks. Patients who received stimulation were discharged from the hospital an average of five days earlier than those who did not.12
This research suggests that electric stimulation of the throat may increase the size of regions in the brain that contribute to the control of swallowing, which may be how stroke patients spontaneously recover swallowing. The procedure may accelerate this process.13
Dysphagia After Intubation
A systematic review of the incidence of dysphagia following endotracheal intubation identifies the limitation of the available evidence and highlights the need for high-quality prospective trials. Researchers conducted the review to determine the incidence of dysphagia following endotracheal intubation, the association between dysphagia and intubation time, and patient characteristics associated with dysphagia.14
Two reviewers separately selected and reviewed articles that examined adult participants who underwent intubation and clinical assessment for dysphagia. Exclusion criteria were case series (n < 10), dysphagia determined by patient report, and patients with tracheostomies, esophageal dysphagia, and/or diagnoses known to cause dysphagia.14
Of the 1,489 citations identified, 288 articles were reviewed and 14 met inclusion criteria. The studies were heterogeneous in design, swallowing assessment, and study outcome. Dysphagia frequency ranged from 3% to 62% and intubation duration from 124.8 to 346.6 mean hours. The highest dysphagia frequencies (62%, 56%, and 51%) occurred following prolonged intubation and included patients across all diagnostic subtypes. 14
Metronome Training Therapy
According to a recent study, training therapy for dysphagia patients with Parkinson’s disease in conjunction with a metronome may improve swallowing function.15
Twenty patients with Parkinson’s disease and moderate dysphagia were divided into two groups. The experimental therapy consisted of cervical stretching, lingual exercise, and deglutition of jelly to the rhythm of six beats of a metronome. The control therapy was identical but without the metronome. When the subjects were evaluated with a Modified Barium Swallow study, the amount of residuals in the valleculae and pyriform sinuses when swallowing jelly was decreased after training with the metronome vs. training without the metronome.15
The results of the study suggested that training with the metronome during swallowing was effective for shortening oral transit time and decreasing the amount of residuals in the pharynx for patients with Parkinson’s disease. 15
Dysphagia Research Continues To Yield Positive Benefits
These four studies are representative of the types of multi-disciplinary dysphagia research that is occurring within the science and healthcare community. Due to new therapies and applications based on these studies, effective solutions for dysphagia patients continue to be developed that may offer physical benefits and improved quality of life for people challenged by swallowing disorders.
- “Increase Swallowing Disorder (Dysphagia) Research”. National Foundation of Swallowing Disorders. January 15, 2013.
- Aydogdu, C. Ertekin, S. Tarlaci, B. Turman, N. Kiylioglu, and Y. Secil, “Dysphagia in lateral medullary infarction (Wallenberg’s Syndrome): an acute disconnection syndrome in premotor neurons related to swallowing activity?” Stroke, vol. 32, no. 9, pp. 2081–2087, 2001.
- J. Cook and P. J. Kahrilas, “AGA technical review on management of oropharyngeal dysphagia,” Gastroenterology, vol. 116, no. 2, pp. 455–478, 1999.
- “Swallowing Disorders After a Stroke,” American Heart Association/American Stroke Association. Stroke Connection Magazine, July/August 2003. (Last science update March 2013.)
- D. G. Smithard, P. A. O’Neill, R. E. England, C. L. Park, R. Wyatt, D. F. Martin, and J. Morris, “The natural history of dysphagia following a stroke,” Dysphagia, vol. 12, no. 4, pp. 188–193, 1997.
- D. Kidd, J. Lawson, R. Nesbitt, and J. MacMahon, “The natural history and clinical consequences of aspiration in acute stroke,” QJM: Monthly Journal of the Association of Physicians, vol. 88, no. 6, pp. 409–413, 1995.
- H. M. Finestone and L. S. Greene-Finestone, “Rehabilitation medicine: 2. Diagnosis of dysphagia and its nutritional management for stroke patients,” Canadian Medical Association Journal, vol. 169, no. 10, pp. 1041–1044, 2003.
- D. G. Smithard, P. A. O’Neill, C. Park, J. Morris, R. Wyatt, R. England, and D. F. Martin, “Complications and outcome after acute stroke: does dysphagia matter?” Stroke, vol. 27, no. 7, pp. 1200–1204, 1996.
- Freed ML, Freed L, Chatburn RL, et al. Electrical stimulation for swallowing disorders caused by stroke. Respir Care. 2001;46:466–474.
- Lim K-B, Lee H-J, Lim S-S, et al. Neuromuscular electrical and thermal-tactile stimulation for dysphagia caused by stroke: a randomized controlled trial. J Rehabil Med. 2009;41:174–178.
- Leelamanit V, Limsakul C, Geater A. Synchronized electrical stimulation in treating pharyngeal dysphagia. Laryngoscope. 2002;112:2204–2210.
- Skoretz SA, Flowers HL, Martino R. The incidence of dysphagia following endotracheal intubation: a systematic review. Chest. 2010 Mar;137(3):665-73. doi: 10.1378/chest.09-1823. Review.
- Nozaki S, et al. Training for Dysphagia with Metronome Improves Swallowing Function in Parkinson’s Disease. University of Health Science, Kobe, Hyogo, Japan.