
BJMB! ! ! ! ! ! ! !
Brazilian(Journal(of(Motor(Behavior(
(
https://doi.org/10.20338/bjmb.v16i5.309
Special issue:
Effects of aging on locomotor patterns
progressive, irreversible condition that exerts a negative impact on cognitive functions and
the performance of activities of daily living
2
. Mild cognitive impairment (MCI) is another
condition that has been investigated in the aging process and constitutes a transition
phase between physiological neuronal loss in the natural aging process and dementia
3
.
Older adults with cognitive impairment have a poorer performance in dual tasks
compared to those with preserved cognition (PrC)
4
. Cross-sectional studies comparing
older adults with PrC to those with some type of cognitive impairment have reported a
negative impact on gait during a dual task in the latter group
5,6,7,8
. These changes may be
explained by a central interference caused by the increase in brain activity during the
simultaneous performance of two tasks and the limitation of attentional resources
9
, which
may decrease performance in one or both tasks and considerably increase the risk of falls
10
.
Although the studies cited have contributed knowledge on dual task performance,
as well as motor performance among older adults with MCI and AD, there is a need for
longitudinal studies to investigate the dual task performance of older adults in different
cognitive status conditions.
Therefore, the aim of the present longitudinal study was to compare the
performance on an isolated task and dual task in older adults with PrC, MCI and mild AD.
We tested the hypothesis that, over time, older adults with PrC, with MCI and AD would
present significant differences when performing the dual task, with worse performance in
older adults who had greater cognitive impairment.
METHODS
Participants
The present study is a sub-study of the longitudinal project called the“Brazilian
longitudinal study about motor alterations in older people with cognitive disorders
(BLSMotorCD)”. This study received approval from the human research ethics committee
(certificate number: 72774317.7.0000.5504) and all the participants or their caregivers
signed a statement of informed consent. At the initial moment (T1), 118 older adults were
recruited, who were evaluated and allocated into three groups: PrC, MCI and AD.
AD and MCI were diagnosed according to the Diagnostic and Statistical Manual of
Mental Disorders (DSM-IV-TR)
11
, including assessments of the Clinical Dementia Rating
(CDR)
12
and Mini Mental State Examination (MMSE)
13
. The confirmation of the diagnosis
was performed at the Department of Medicine at the Universidade Federal de São Carlos
(UFSCar) by a trained team coordinated by Dr. FACV at the Behavioral Cognitive
Neurology Clinic.
After 32 months (T2)
10
, one hundred and eighteen older adults were contacted
again by the evaluators. Of these, fifty-one individuals participated in T2 (10 with AD, 19
with MCI and 22 with PrC). Reasons for discontinuation during the study period were
withdrawal (n = 23), loss of contact (n = 12), death (n = 11) and exclusion
(bedridden/restricted to a wheelchair: n = 18; severe behavioral disorder: n = 3).
Procedures
The two evaluators at T1
5
and T2 were blinded to the allocation of volunteers in
the different groups and underwent a reliability analysis. The inter-examiner reliability test