Abstract:
Post-Stroke Cognitive Impairment (PSCI) is a major cause of disability, dependence on Activities of
Daily Living (ADL), Participation Restriction (PR) and poor Quality of Life (QoL). Evidence has shown
that the gold standard for PSCI rehabilitation is Cognitive Rehabilitation (CR). Studies have also shown
that aerobic exercises with treadmills and bicycle ergometers are effective in the management of PSCI.
However, only few studies have examined the effects of Overground Walking Exercise (OWE), which
is an inexpensive, accessible and natural form of aerobic exercise. This study was conducted to
investigate the comparative effects of an eight-week OWE and Cognitive Rehabilitation (CR) on
cognition, Brain-Derived Neurotrophic Factor (BDNF), QoL and PR among stroke survivors.
The study design was randomised-controlled trial, which involved 53 stroke survivors with mild-tomoderate cognitive impairments, purposively recruited from three tertiary hospitals in Kano, and
randomly assigned into three groups using computer-generated random numbers. The participants
received moderate-intensity self-paced OWE, Zoltan protocol CR and combined interventions in the
respective groups (OWEG=17, CRG=18 and OWECRG=18). Each group received thrice weekly
interventions for eight weeks. About 5 ml venous blood sample was collected aseptically, allowed to
clot and centrifuged to harvest the serum sample. Cognition, serum BDNF (ng/ml), QoL and PR were
assessed using Montreal Cognitive Assessment, Enzyme-Linked Immunosorbent Assay (ELISA)
technique, Stroke-Specific Quality of Life questionnaire and London Handicap Scale, respectively at
baseline, 4th week and 8th week. Data were summarised using descriptive statistics and ANOVA at
α0.05.
Age of participants was 48.42±27.39 years. At baseline, duration since stroke onset was 26.70±27.25
months. The OWEG, CRG and OWECRG were comparable in cognition (18.06±3.60; 19.00±3.90;
19.50±3.85); BDNF levels (13.05±8.27; 13.81±11.04; 9.54±6.46); QoL (191.00±28.85; 202.72±28.83;
197.44±39.83) and PR (12.06±4.02; 10.39±4.24; 10.56±3.31) at baseline. Within-group comparisons at
week 4 showed significant improvements in cognition (20.53±2.83; 22.78±3.95; 22.44±3.37); BDNF
levels (13.88±8.26; 15.62±12.98; 11.54± 9.17) and QoL (202.24±22.49; 211±21.99; 204.17±41.24) for
the OWEG, CRG and OWECRG, respectively. The PR significantly decreased to 9.00±2.45; 9.56±2.73
and 9.44±3.47 at week 4 for the OWEG, CRG and OWECRG, respectively. Similarly, within-group
comparisons at week 8 showed significant improvements in cognition (26.24±2.51; 25.22±3.26;
25.17±3.47); BDNF levels (14.69±8.85; 18.13±14.96; 13.35±10.56) and QoL (243.53±17.84;
222.89±18.35; 221.28±25.72) for the OWEG, CRG and OWECRG, respectively. There were significant
reductions in PR to 7.24±2.05; 8.39±2.70; 8.39±2.43 at week 8 for the OWEG, CRG and OWECRG,
respectively. There was no significant across-group difference in cognition, BDNF levels and PR. The
percentage mean changes at week 8 in cognition (45.3%, 32.7%, 30.5%) and PR (40.0%, 19.3%, 20.6%)
were highest for the OWEG, while the percentage mean change in BDNF level was highest in the
OWECRG (12.6%, 31.3%, 38.3%). There was a significant across-group difference in QoL at week 8,
with the best improvement observed in the OWEG.
Overground walking exercise, cognitive rehabilitation and a combination of both had comparable
positive effects on cognition, level of brain-derived neurotrophic factor, and participation. However,
overground walking exercise resulted in better improvement in participants’ quality of life.
