Dysphagia in patients with dementia: Alzheimer versus vascular

Abstract

Patients with dementia develop dysphagia some time during the clinical course of their disease. The aim of this study was to compare the swallowing functions of the 2 most common types of dementia: Alzheimer disease (AD) and vascular dementia (VaD). Videofluoroscopic swallowing studies of the 2 patient groups were analyzed according to various oral, pharyngeal, and laryngeal variables of swallowing. The results indicate that there are some different patterns of swallowing disorders. The AD patients were significantly more impaired in "oral transit delay over 5 seconds" with liquids (chi2=7.065, df=1, P=0.008), whereas the VaD patients showed more deficits in "bolus formation and mastication" of semisolid food (chi2=4.64, df=1, P=0.039), "hyolaryngeal excursion" (chi2=4.102, df=1, P=0.043), "epiglottic inversion" (chi2=4.612, df=1, P=0.032), and "silent aspiration" (chi2=6.258, df=1, P=0.011). These results could indicate that the swallowing disorders of the AD group may result from sensory impairment in relation to dysfunctions in the temporoparietal areas, whereas the swallowing disorders of VaD group may primarily be caused by motor impairments due to disruptions in the corticobulbar tract. This study is noteworthy because it is one of the first attempts to differentiate between the swallowing symptoms of AD and VaD patients. A further study that includes patients with more severe degree of dementia (eg, patients over clinical dementia rating 3) might delineate additional discriminating swallowing patterns between the 2 dementia groups. In addition, a follow-up study exploring various kinematic characteristics of dysphagia would address physiologic issues of swallowing disorders as related to one of the most important clinical variables, laryngeal aspiration in the 2 dementia groups