Impact of Medical Diagnosis on Swallow Function
Dysphagia is not a disease but rather a symptom of a disease. While there is great variability across dysphagia profiles, there are some commonalities within a medical diagnosis. This section provides a brief summary of some common clinical and instrumental signs of dysphagia by medical diagnosis.
Stroke
Oropharyngeal dysphagia is a common sequela for individuals who have suffered a stroke (a.k.a.,cerebral vascular accident). In fact, more than half of the individuals who suffer a stroke will have some reduction in swallow efficiency or safety (Crary, Carnaby, Sia, Khanna, & Waters, 2013; Falsetti et al., 2009). While there are some consistencies in the swallow deficits noted post stroke, there is much variability across individuals. As the incidence of stroke is increased with age and poor cardiovascular health, the variability in swallow disorders post stroke is related not only to the type, location and size of the stroke, but also the age of the individual and the presence of comorbidities. Therefore, it is a complex task to define a classic dysphagia profile for individuals post stroke. However, some swallow deficits are more characteristic of this population.
Swallow deficits commonly observed in patient’s status post acute stroke may be related to the location of the stroke. Recall that the swallow central pattern generator is located in the medulla. Damage to this area can have a devastating impact on swallow function. However, cortical strokes can also alter swallow efficiency and safety. Strokes that unilaterally involve the primary motor cortex can alter bolus management, particularly on the side with motor weakness (contralateral to the cortical damage). Strokes that involve the primary sensory cortex can alter bolus awareness and response time to the bolus. Neglect, which may occur with right hemisphere strokes, can result in a reduced ability to manage mealtimes due to inattention to food and liquid on the left side of the plate or food tray.
Common clinical predictors of dysphagia in this population may include a weak spontaneous cough or abnormal volitional cough, abnormal gag reflex, dysphonia or vocal quality changes related to oral intake, and dysarthria. The presence of two or more of these signs is linked to an increased risk of aspiration pneumonia (McCullogh et al., 2001; Daniels, Ballo, Mahoney, & Foundas, 2000). Instrumental evaluations may reveal unilateral reductions in bolus flow resulting in protracted transit times and a slow response time, with an increased potential for residue, particularly on the effected side. While delayed pharyngeal swallow trigger is not a significant finding in elderly individuals, the length of the delay should be considered, as well as its imposition on the safety of the swallow. Aspiration, with or without a response, may be present before or after the swallow.
Clinical Note
Common swallow deficits in stroke include poor bolus formation and