Usefulness of a Virtual Response Test as a Predictor of Functional and Cognitive Abilities in Older Adults With Different Degrees of Cognitive Impairment: a Pilot Study (ReactVR)

1. BACKGROUND Population aging is one of the most significant trends of the 21st century.In 2020, 21% of the European population was 65 years of age or older, compared to 16% in 2001.Today, 1 in 9 people is over 60, but it is estimated that by 2050, this will be 1 in 5. Therefore, population aging is a phenomenon that can no longer be ignored. In recent decades, the increase in the number of older people is due to the increase in life expectancy. By 2026, the average life expectancy for men is estimated at 77.65 years, and for women, values are projected to reach 85.5 years.

Aging is generally associated with neuromuscular deterioration (such as sarcopenia), gait and balance disorders and loss of mobility. In general, a loss of functional independence. In the population over 60 years of age, approximately 3% of muscle strength is lost per year due to muscle denervation and the conversion of type II muscle fibers to type I muscle fibers, decreasing their muscle power for performing activities of daily living. This muscle weakness eventually leads to frailty in older adults, and, consequently, an increased rate of falls and fractures.

Cognitive ability is also closely related to motor ability, since there are cognitive requirements for developing all physical functions and balance, and these can be altered when attention is diverted or reduced. Executive function and processing speed are some of the cognitive functions related to postural stability, which can be impaired in older adults with cognitive decline. Cognitive decline and dementia are geriatric syndromes with a fairly high incidence. Around 7% of those over 65 years of age are affected. affected, a percentage that increases to 50% for people over 80 years old, which means that more than 1.5 million people in Spain directly suffer from this condition.

Furthermore, the risk of falls is linked to reaction times, which involve both cognitive and motor aspects (discussed above). These combine attention, perception, and information integration with the final motor response, as well as psychological and emotional factors such as fear of falling or insecurity. Currently, one in three adults over 65 and one in two adults over 80 fall each year, making it a serious public health problem among older adults, as falls lead to premature mortality, loss of independence, and admission to assisted living facilities.

A widely used scale for predicting the risk of falls is the Time Up and Go (TUG) test. The patient is asked to stand up from a seated position, walk three meters, turn around, and return to the starting position while the time is measured. Patients who do not complete the test in less than 13.5 seconds are considered to have a high risk of falls. Although it is included in various clinical guidelines, the literature recommends identifying alternative tools that can more accurately identify patients at risk of falls, as several studies have shown that the accuracy of this test is limited. Within the TUG (Trauma Glide Test), we have the cognitive TUG (TUG-cog), which assesses the previous test but with the interference of a concurrent cognitive activity. In neurological processes, such as Alzheimer's disease, deficits in divided attention and the ability to perform dual tasks appear to be related to functional mobility impairments, directly linked to the risk of falls.

Currently, there are also simple reaction time tests (SRTT), which consist of a computerized test to measure a person's reaction times by pressing a response button with the index finger of their dominant hand. However, there is controversy regarding the influence of motor disability on performance in the computerized SRTT task assessment, since the response depends on the ability to press a key with a finger.

The use of virtual reality software could facilitate the measurement of reaction times in performing functional tasks-tasks that require greater upper limb mobility, which can be a key factor in preventing falls-without being limited to measuring the movement of a single finger. 2. HYPOTHESES AND OBJECTIVES H0: Knowing the functional reaction times assessed with virtual reality does not help to understand the integrity of the physical, functional, and cognitive abilities of older adults with cognitive impairment, nor can it predict their risk of falling or their level of cognitive impairment.

1) General Objective 1.1 To determine the feasibility of using a virtual reaction time test (VRTT) as a predictor of falls and the level of cognitive impairment in older adults with cognitive impairment.

2) Specific Objectives 2.1 To analyze the relationship between the VRTT and the risk of falling as measured by the Timed Up and Go (TUG) Test. 2.2 Analyze the relationship between VRTT obtained in the virtual test and the level of cognitive impairment measured with the Cambridge Cognitive Examination (CAMCOG). 2.3 Estimate TUG and CAMCOG scores based on reaction times obtained in the VRTT