People with dementia have an increased risk of a COVID-19 infection. They also are more likely to develop a severe form of the disease. That has not only to do with age or the corona measures, but also with the genetic factor APOE4. A group of international researchers, led by professor Philip Scheltens from the Alzheimer Center Amsterdam, published a systematic review in the journal Alzheimer & Dementia.

At risk of a COVID-19 infection

The impact of the COVID-19 pandemic on healthcare of patients with dementia is enormous. Elderly people with Alzheimer's disease or another form of dementia are faced with lower quality care and extra risks in various institutions. Recent data suggests that people with dementia are more likely to develop a severe COVID-19 infection. Even when factors such as aging and chronic illnesses (e.g. high blood pressure and diabetes) are excluded. It might be that public health measures, such as physical distance or lockdown, have greater adverse effects on the well-being of elderly people with dementia, but there are also biological explanations.

Genetic factor

One of the risk factors for Alzheimer's disease is the ApoE4 gene variant. Sixty percent of Alzheimer's patients have this variant, against less than fifteen percent of the general population. A COVID-19 study showed that this factor plays a role in the development of neurological complications in COVID-19. This is because in people with the ApoE4 gene variant the blood-brain barrier functions less. In addition, the gene has a negative influence on the general immune response.

Practical suggestions

The knowledge about the ApoE4 genetic variant and the negative consequences of the health measures are listed by 35 international researchers in a systematic review, led by Philip Scheltens of the Alzheimer Centrum Amsterdam. The group researchers have provided an overview on the profound impact of COVID‐19 upon older people with Alzheimer's disease and other dementias and the challenges encountered in our management of dementia in different health‐care settings, including hospital, out‐patient, care homes, and the community during the COVID‐19 pandemic.

With a conceptual framework and practical suggestions for healthcare providers they want to help tackle these challenges, which can also apply to the care of older people in general, with or without other neurological diseases, such as stroke or parkinsonism.