Research Background

Researchers have indicated that the many cases of feeding, mastication, and swallowing disorders are reversible (Yamada, 2002). Nursing care, which is mainly based on environmental regulations, can improve the disorders (Yamada, 2003, 2011) according to the eighteen-year cumulative studies before the start of this project.

Feeding, mastication, and swallowing disorders can be associated with dementia. Dementia is a syndrome correlated with causes. Presently in Japan, Alzheimer disease (AD) is the most common cause presenting with dementia. Vascular dementia (VaD) and dementia with Lewy bodies (DLB) follow. In addition, frontotemporal dementia (FTD), for which the international guidelines were established in the 1990s, is on the rise. However, for now, there are few reports that describe the characteristics of feeding, mastication, and swallowing disorders according to the stage of FTD and DLB (Yamada, 2009; Shinagawa et al., 2008; Ikeda et al., 2002). In addition, it is said that 20% of people with dementia, who are diagnosed with AD, are in fact suffering from DLB. To implement the study, the establishment of a differential diagnosis is needed by medical specialists. Although scientific studies have been carried out (Yamada et al., 2011; Edahiro et al., 2010; Hirano et al., 2011), the differential diagnosis for dementia remains an unsolved problem. For the above reasons, the characteristics of feeding, mastication, and swallowing disorders depending on the severity of FTD and DLB and the cases on the care skills that deal with such disorders need to be accumulated in collaboration with dementia medical specialists. This is the first unsolved issue.

The second unsolved issue is the evaluation of the care for feeding in the terminal phase of dementia. Recently, nutritional management method is controversial in Japan. However, the guidelines for the terminal phase of dementia have been established overseas already. Tube feeding in the end-stage dementia is not applicable in the U.S. and Australia on the ground that the prognosis is poor because of the rise in the number of aspiration by increased respiratory secretions, death from suffocation caused by gastroesophageal reflux, and high risk of aspiration pneumonia (Gillick, 2000). In Japan, the Practice Guideline for the Treatment of Patients With Alzheimer's Disease and Other Dementias (2010) suggests the pursuit of the possibility of feeding in the terminal stage. Facilities are increasing where end of life care is provided without the risk of aspiration pneumonia and transition to tube feeding until the end. Consequently, early evaluation on feeding care skills in the terminal phase of dementia with analysis of the case is required.

The third unsolved issue is that the relationship between wakefulness-sleep rhythm disorder and feeding, mastication, and swallowing disorders in the elderly with dementia and the care skills that deal with the problem have been unclear. Being awake for feeding is the major premise. However, the elderly with dementia develops easily wakefulness-sleep rhythm disorder (Hagino, Yamada and Ede, 2006). Regarding the relationship between sleep and wakefulness rhythm and feeding, they tend to sleep at breakfast and lunch time. Care skill, such as the utilization of the opportunity to feed at dinner time is suggested (Hagino, 2009). Further empirical study is required.

The fourth unsolved problem is the need to explore on the care skills for the management as well as the evaluation of mastication function depending on the causes and severity of dementia. Although the study by Yamada et al. (2011) recognized a strong correlation (ρ=.785, p<.001) between the rate of self-feeding and mastication function, the assessment of oral function at clinical practice and inadequate care had scientifically proven the correlation. Furthermore, mastication inactivates the brain function. Consequently, the perspective of re-evaluation of mastication function for the elderly with dementia and the review of the corresponding care skills are necessary. Mastication plays a major role in eating foods deviously as a human being more than anything. Therefore, for the elderly with dementia who have a swallowing disorder, a new twist to eating habits with a high regard for swallowing, as well as pharyngeal stage, will be required.