Dementia as a risk factor for aspiration in patients with COVID‐19

Dear Editor,

We read a recent report in this journal that focused on the effects of dementia on mortality in patients with coronavirus disease 2019 (COVID‐19).¹ In general, dementia can be confounded by age or other comorbidities when assessing prognostic factors, but the report indicated that dementia was significantly associated with mortality, even after adjusting for these variables.

However, it is hard to imagine that dementia is a direct cause of death in patients with COVID‐19. Dementia is a risk factor for swallowing dysfunction and aspiration.² Presumably, dementia may cause aspiration pneumonia, which in turn might increase mortality. We have published a systematic review demonstrating that aspiration risks are associated with poor prognosis in patients with community‐acquired pneumonia.³ This association might be common in patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pneumonia.

While SARS‐CoV‐2 infection has been reported to affect neuromuscular function,⁴ whether it specifically weakens the swallowing function is still uncertain. However, it is conceivable that an altered level of consciousness with fever and fatigue may be a risk factor for aspiration. We used the repetitive saliva swallowing test (RSST) to assess changes in the swallowing function of a middle‐aged man with COVID‐19 and a history of brainstem infarction. RSST is a screening test in which the patient is asked to swallow saliva as many times as possible for 30 s, and deglutition is counted through palpation of the larynx.⁵ For this patient, the RSST revealed a depressed swallowing function (2 swallows/30 s) 10 days after the onset of the disease (day 10); the patient's score increased to 3 swallows/30 s on day 15, after his body temperature had returned to normal on day 13. During a follow‐up visit on day 42, the patient's swallowing function had recovered (5 swallows/30 s), as shown in Figure 1.

Figure 1.

Clinical course of coronavirus disease 2019 in a patient subjected to the repetitive saliva swallowing test (RSST). AZM, azithromycin; CRP, C‐reactive protein; SBT/ABPC, sulbactam/ampicillin; TFLX, tosufloxacin; WBC, white blood cell.

Not only SARS‐CoV‐2 infection but also most other infectious diseases can decrease the level of consciousness and possibly cause a deterioration in the swallowing function.⁶ Especially among patients having risk factors for aspiration, such as dementia or a history of brainstem infarction, potential swallowing dysfunction might become clinically evident following SARS‐CoV‐2 infection. These comorbidities are likely to be confounded by risk factors for aspiration, which might predict the prognosis in patients with COVID‐19.

Disclosure statement

All authors have stated that there are no conflicts of interest in connection with this article.

Yoshikawa H, Komiya K, Hamanaka R, Hiramatsu K, Kadota J. Dementia as a risk factor for aspiration in patients with COVID‐19. Geriatr. Gerontol. Int. 2021;21:757–758. 10.1111/ggi.14217