**1. Introduction**

Europe is a country that is getting older every day. An increasingly significant number of people find themselves in a condition of vulnerability and are at greater risk of suffering a functional loss and/or loss of autonomy [1, 2]. These conditions have been accentuated during the health emergency due to the current pandemic situation [3].

The elderly population has been burdened with a higher incidence and mortality of infection: the older adults have been shown to contract the infection in a more severe clinical form and this is especially true in Europe which, having, after Japan, the highest percentage of elderly people, has paid a very high toll in terms of mortality [3]. More than 95 per cent of the deaths involved people over the age of 60, and 50 per cent of all deaths were aged ≥80 [4].

The disease did not strike indiscriminately; it was mainly the elderly with serious concomitant chronic diseases (cardiovascular diseases, respiratory diseases, diabetes, neurodegenerative diseases, oncological diseases, etc.) who paid the highest price in terms of mortality [3, 4]. A particular incidence of fatal events has occurred among people living in social and health care residences throughout Europe [3, 4]. It is reasonable to assume that the virus has affected residential care facilities because of the community life that takes place there, affecting people already suffering from frailty and polypathology, so that the damage caused by the virus has been superimposed on that caused by coexisting diseases.

Considering the above, social distancing measures severely penalized the elderly, since they needed to be isolated as they could act as healthy carriers for the community and, if they became ill, would produce extraordinary pressure on intensive care [4].

The Covid-19 pandemic has also brought to light the concept that it is above all the frail elderly who are at high risk of functional, cognitive and psycho-social disabilities that make it difficult for the elderly to return to their pre-infection condition: this is the key to interpreting the relationship between the elderly and the coronavirus infection.

This inference is derived from what is observed about the global population. It seems increasingly likely that the majority of all those infected wills experience chronic sequelae of the disease, resulting in disability or diminished quality of life, a phenomenon now described as "*long-covid*" [5, 6]. Indeed, COVID-19 survivors can suffer from persistent symptoms after recovering [5], especially related to organ damage, post viral syndrome, and post-critical care syndrome [6]. Long-covid is characterized by breathlessness, chest tightness, cough, fatigue, myalgia, palpitations, sleep disorders and difficulty to focus [5, 6]. Anxiety and depression were also reported [5].

The SARS-CoV-2 pandemic has rekindled attention on the possible neurovirulence of this virus and the possible involvement of the central nervous system and peripheral nervous system [7, 8]. The spectrum of central and peripheral nervous systems disease in COVID-19 patients is much broader than previously thought. Some form of "*neurocovid*" appears to occur in up to 30% of positive patients. It is therefore a phenomenon that deserves to be carefully investigated and evaluated when screening and monitoring short- and long-term patients, especially the elderly.

#### **2. Aging, frailty, and COVID-19**

Aging is a natural phenomenon involving a progressive physiological transformation of the human body and of neuropsychological and behavioral functions [1, 2]. The aging phenomenon, in addition to the growing quantitative data on the total population, is characterized by the different attributes that qualitatively characterize this process and transition. In fact, elderly life is structured by different levels of independence and dependence of individuals with respect to both primary family networks and secondary networks of assistance and care [1, 2].

The conceptualization of frailty is presented as an attempt to define this heterogeneity of conditions. Frailty is a condition of marked vulnerability to adverse events caused by a reduction in the functional reserves of multiple systems of the body due to the aging process and chronic polypathology. It is a condition that represents a risk factor for disability, hospitalization, institutionalization, and death [1–3]. At first, frailty appeared in the literature with a distinctly bio-medical or clinical meaning [9], but in the last decade it has acquired bio-psycho-social

*"Neurocovid": An Analysis of the Impact of Covid-19 on the Older Adults. Evolving Psychological… DOI: http://dx.doi.org/10.5772/intechopen.99414*

connotations as well as medical ones. Starting from the works of Gobbens et al. [10] and Van Campen [11], it is preferred to define frailty as a condition of vulnerability at a bio-psycho-social level. Today we prefer to speak of frailty in the plural. There are functional, cognitive, psycho-social, clinical, and - finally - economic frailty. These different dimensions interact together in moments of greatest difficulty. The definition of "frail elderly" therefore refers to a person who, faced with a stressful event -such as the SARS-CoV-2 pandemic - is unable to respond adequately, and therefore succumbs, with an increased risk of adverse events: mortality, disability and worsening of his/her general condition.

An increasingly significant number of older people are in a frail state, making this a hot topic. Physical and cognitive frailty have proved more useful than ever in understanding the impact of the SARS-CoV-2 pandemic on the elderly population and in guiding the principles of vaccine clinical trials [3]. Indeed, not only frail older people are particularly vulnerable to serious or life-threatening infections, but the age-related dysregulation of the immune system (due to immunosenescence and inflammaging) results in poorer responses to vaccination [3].
