Maneuvering With Difficulty Around Jagged Edges: A Unique Case of Mixed Dysphagia Causing Recurrent Aspiration Pneumonia: Page 2 of 3

September 15, 2011


Dysphagia is the inefficient or unsafe transfer of food, liquids, or saliva from the mouth to the stomach. Complications of dysphagia include aspiration pneumonia, asphyxiation, malnutrition, and dehydration. Early identification and treatment of dysphagia is associated with reduced morbidity and improved quality of life. Common causes of dysphagia in the elderly include PD, stroke, Alzheimer’s disease, Huntington’s disease, brain tumors, myasthenia gravis, achalasia, gastroesophageal reflux disease, and esophageal tumors.

Drug-induced dysphagia is also common, especially with use of nonsteroidal anti-inflammatory drugs, potassium supplements, and bisphosphonates, all of which can injure the esophagus. Anticholinergic drugs that nowadays are rarely used to treat elderly patients with PD can cause dysphagia through various mechanisms, such as inducing cognitive deterioration, decreasing saliva output, and impeding lubrication of the food bolus as it travels from the mouth through the pharynx into the esophagus. DISH, which can involve the impingement of cervical osteophytes on the esophagus or oropharynx as we observed with our patient, is a rarer cause of dysphagia.


Diffuse Idiopathic Skeletal Hyperostosis

DISH was first described by Jacques Forestier and Jaime Rotés-Quérol in 1950 and is sometimes called Forestier’s disease.2 The axial skeleton, particularly the thoracic spine, tends to be affected in DISH. Because of this, the condition was initially called senile ankylosing hyperostosis. The discovery that the disease targets the enthuses (points where ligaments and tendons attach to the bone that are rich in mesenchymal cells, fibroblasts, and collagen fibers) and often involves the peripheral joints as well as the spine resulted in it being renamed DISH.4,5 DISH is usually asymptomatic and discovered incidentally on routine radiography; when patients are symptomatic, they typically present with stiffness in the thoracic region.

DISH is more common in men than in women and affects up to 10% of individuals ≥65 years of age.3 It is more prevalent among white people, Japanese individuals, Pima Indians, blacks of African descent, and Jews; DISH is less common among American blacks.6

The pathogenesis of DISH is unknown, but it has been suggested that the ossification and consequent new bone formation results from the abnormal growth and activity of osteoblast cells in the bony ligamentous region.7 Studies have identified higher levels of insulin and growth hormones in patients with DISH, which may explain the accelerated growth and proliferation of the osteoblast cells that has been observed.8-10 Insulin-like growth factor 1 stimulates alkaline phosphatase activity and type 2 collagen synthesis in the osteoblasts, and growth hormone has been linked to the production of insulin-like growth factor 1 and insulin-like growth factor binding proteins in both chondrocytes and osteoblasts.8

DISH has many diagnostic criteria, but diagnosis generally requires the following: radiological evidence of flowing calcification and ossification along the anterolateral aspect of at least four contiguous vertebral bodies, with or without osteophytes; preservation of disc height in the involved areas, together with absence of disc disease; the absence of bony ankylosis of facet joints; and no involvement of the sacroiliac joints.11 The current classification system that is widely used is limited to vertebral involvement and does not take peripheral manifestations of DISH into consideration. One proposed classification system incorporates peripheral enthesopathies in the diagnostic criteria, and it is likely that peripheral joint and entheseal site involvement will someday be used to help diagnose DISH.12

DISH is distinguishable from OA because it affects joints that OA typically does not, like the metacarpophalangeal joints, shoulders, and elbows.5,13,14 Additionally, DISH has also been found to affect ligamentous insertions such as the peripatellar and cruciate ligaments.15 Pain in the heels, ribs, and pelvis due to ossification of the entheseal areas may also be part of the clinical picture. Although clinical symptoms are often misattributed to OA, correctly diagnosing DISH will allow clinicians to anticipate possible complications, such as dysphagia and aspiration pneumonia, as seen in our case patient; spinal stenosis; myelopathy; unstable spinal fractures; and difficulty with bronchoscopy or gastroscopy.16,17 Osteophytes are common in elderly patients with DISH and can lead to compression of local tissues.


Dysphagia Secondary to DISH 

In rare cases, patients with DISH may present with dysphagia due to mechanical obstruction of the esophagus from osteophytes, which develop mainly at fixed points along the esophagus, such as at the level of the cricoid cartilage. Compression of the esophagus by anterior cervical osteophytes can cause throat aches, difficulty swallowing, and a sensation of a foreign body in the throat, a triad of symptoms that characterize Eagle’s syndrome.18 Dysphonia (impairment in the ability to produce voice sounds using the vocal organs) with dyspnea is an exceedingly rare presentation in patients with DISH and may be observed in those having large anterior cervical osteophytes.19,20 Nevertheless dysphonia and dyspnea are rare presentations, in view of the interposition of the esophagus between the cervical spine and the larynx and trachea. Respiratory symptoms, such as dyspnea from cervical osteophytic compression on the trachea, range from mild to severe and, in extreme cases, may require emergency tracheotomy.21 The respiratory symptoms probably result from ulceration of the cricoid cartilage, caused by laryngeal movement over the large osteophyte. The ulcers predispose patients to infection, inflammation, edema, and possible secondary bilateral cord paralysis with airflow obstruction.22

CT scanning can confirm osteophyte impingement of the esophagus by showing the position of cervical osteophytes in relation to the esophagus, larynx, and trachea. Magnetic resonance imaging is occasionally performed to determine whether laryngeal necrosis is present and the degree of encroachment by the osteophytes, especially when surgical treatment is being considered. A videofluoroscopic swallowing study is another useful diagnostic modality, as our case demonstrates. This study can show anatomical encroachments, abnormalities with any phase of swallowing, and aspiration during consumption of fluids with various thicknesses. Videofluoroscopy has the added advantage of delineating compression due to osteophytes from other extrinsic causes of compression, such as thyroid enlargement or esophageal tumors. However, to mitigate the risk of esophageal perforation and other dangerous injuries, caution should be used when employing this modality. 23

As with the patient in our case, DISH-related dysphagia is typically managed conservatively. Usually diet modification and regular consultations with a speech-language pathologist suffice, but some authorities recommend treating patients with nonsteroidal anti-inflammatory drugs, antibiotics, and steroids.24

Surgical excision of the osteophyte(s) is reserved for patients whose nutritional status is impaired or those who have a compromised airway. An anterolateral approach is generally used during the procedure because it offers better exposure of the great vessels and vagus nerve; however, this approach also places the recurrent laryngeal nerve at greater risk.25 The
posterolateral approach widely exposes the prevertebral space, but it requires greater retraction of the carotid sheath. The transoral route offers a cosmetic advantage and is associated with minimal risk of damage to major vessels and nerves, but exposure of the cervical spine is limited with this technique, which may place patients at risk of fascial infection and even osteomyelitis. Patients are generally able to take fluids by mouth 24 hours postoperatively and can expect to be free from respiratory or swallowing problems within 1 week. Reossification may recur in the long term, but patients previously treated operatively typically remain asymptomatic. None of the available treatments for DISH prevent reossification.26


Dysphagia and Silent Aspiration in Parkinson’s Disease

Swallowing abnormalities affect 94% of patients with PD but may go unnoticed early in the course of the disease.27 Dysphagia in PD is due primarily to catecholaminergic degeneration and Lewy body formation in the brainstem and pharyngeal muscles. Other PD-related factors that contribute to an increased risk of dysphagia and, consequently, aspiration pneumonia include cognitive impairment, upper limb bradykinesia, and impulsive feeding disorders. Although PD-related dysphagia most commonly involves the oral phase, it can also arise from problems during the pharyngeal and esophageal phases of deglutition.28,29

In the oral phase of swallowing, impaired movement of the mandible by PD can lead to prolonged chewing and, hence, a prolonged oral phase.30 Some consider “tongue pumping” as pathognomonic of PD.31,32 This is when the patient’s tongue moves back and forth, possibly several times, delaying the swallow and preventing bolus from reaching the pharynx. Patients with PD may appear to have excessive saliva production, but the drooling of saliva or oral fluids seen with PD is typically due to delayed swallowing and a flexed neck. In fact, 55% of patients with PD actually suffer from xerostomia, or dry mouth,33 due to use of drugs such as levodopa or anticholinergic agents, which inhibit saliva production.34

Patients with PD may experience mild delays in initiating the pharyngeal phase of swallowing,28 which also increases their risk of aspiration. Inhibited movement of the tongue-base and posterior pharyngeal wall sometimes allows food residue to remain in the vallecula and piriform sinuses after swallowing.35 This residue sometimes drops into the open, unprotected airway, where it is then aspirated into the trachea and lungs. Patients with PD may have reduced laryngeal elevation and delayed laryngeal closure, and those with cricopharyngeal dysfunction and an impaired cough reflex have a greater risk of aspiration.36

The incidence of silent aspiration is high in PD and conveys a significant risk of aspiration pneumonia,37 with pneumonia having long been recognized as a leading cause of death in patients with advanced PD.38 Aspiration pneumonia mainly occurs in patients with poor oral hygiene that results in infected oral secretions and in patients with limited oral movement. Videofluoroscopy may be used to detect swallowing abnormalities, as with the patient in our case study, who was found to have limited tongue elevation and demonstrated signs of aspiration with the consumption of thin fluids.

Management of PD-associated dysphagia is difficult. PD demonstrates only limited response to conventional therapy with dopaminergic agents.39 Administering drugs to treat PD is impeded by reduced tongue movement, cricopharyngeal dysmotility, and pill retention in the vallecula, resulting in erratic delivery of the drug.

Administering treatment prior to feeding may improve upper limb dexterity while eating and possibly help oropharyngeal function.28 Adaptive utensils are also helpful. In patients with PD-associated dementia, caregivers should be instructed to prolong mealtimes.

In advanced cases of PD-related dysphagia, a percutaneous endoscopic gastrostomy may be required, but this does not preclude the patient from orally taking in some nutrients.28 For patients whose drooling interferes with eating, caregivers can alleviate the problem by keeping the patient in an upright posture during feeding, wiping drool from the patient’s mouth and chin, and encouraging the patient to swallow more frequently; reducing fluid intake for these patients is not recommended. Some compensatory strategies that can be attempted include having the patient eat upright, with chin tucked to the chest; offering foods that enhance sensory input, such as seasoned, cold, or sour foods and carbonated beverages; and changing food consistency, avoiding viscous or thin fluids.

Other maneuvers that a speech language pathologist might prescribe include active tongue and lip exercises, together with falsetto exercises to help laryngeal elevation. To reduce the risk of aspiration, consider instructing patients with intact cognitive abilities on effortful swallowing, the Mendelsohn Maneuver, and the double swallow, followed by a cough.27 Studies are currently underway that are evaluating the use of expiratory muscle strength training.40