Tamaya Van Criekinge, PT
Approximately 30% of stroke survivors will be cognitively impaired in the five years following their diagnosis. Limited evidence is available on the combined effects of cognitive and physical exercise on the recovery of cognition after stroke. The authors of the current study aimed to explore this unique treatment strategy by providing a dual-approach exercise program of combined aerobic and resistance training (CARET) with cognitive training. They sought to investigate the feasibility, adherence, and safety of this high-intensity treatment protocol prior to targeting effectiveness.
This feasibility study included 131 adult stroke survivors, within one year of diagnosis, and by simple randomization were distributed into an intervention group (n=86), CARET-cognitive, and a control group (n=45). Participants received interventions thrice weekly for 40 to 60 minutes of CARET and 40 minutes of cognitive interventions. The CARET exercises consisted of treadmill or bicycle ergometer for aerobic training, while core exercises and weight machines were used for strength training. Training intensity initiated at approximately 50% of the maximum heart rate and was gradually increased to 65%, if possible. Cognitive training was aimed at improving auditory and visual attention, as well as memory, working memory, processing speed, and executive function. The following selected exercises of the computerized program of BrainHQ from Posit Science were performed: target tracker, double decision, eye for detail, fine tuning, scene crasher, card shark and juggle factor. The control group received sham therapy, including stretching, range of motion exercises, and/or computer games such and anagrams and word searches.
Primary outcome measures were, first of all, feasibility and adherence to the 12-week intervention, as this is a high-intensive training program. In addition, secondary assessment included cognition by means of the Montreal Cognitive Assessment and multiple specific tests, mood with the Depression Scale of Center of Epidemiological Studies, quality of life assessed with the Stroke Impact Scale and physical assessment by means of the Timed Up and Go test, 15 meter walk and 6 minute walking test.
Results showed that only 42% of the participants in the control group and 63% completed at least 80% of scheduled sessions, resulting in a total drop-out rate of 28%. However, adherence was better in the intervention groups as compared to the control group. Reasons for drop-out in the intervention group was mostly a lack of time, while the control group stated that the therapy was not challenging enough. Although significant improvements were found for mood, cognition, quality of life, strength and cardiovascular fitness in the intervention group, significant between-group differences were not present after adjusting for baseline differences.
Although no between-group difference was found in this feasibility study, the combination of aerobic exercise with cognition shows great promise to tackle both the physical and cognitive impairments after stroke and should be investigated in a larger clinical trial. Current evidence supports that the training can be executed safely with no severe adverse events. An important additional finding from this study is the importance of providing challenging exercises for a control group. Sham treatment should not just be a pastime, but it has to be meaningful and demanding for patients to sustain, especially as it takes up so much of their time. The authors suggest that 1-to-1 training is a possibility to keep participants engaged in order to reach their goals. Although this is true in theory, this will be difficult to translate in clinical practice as the economic cost related to one hour of individualized therapy is high. Nevertheless, it is very important to find effective strategies for improving cognition in people with acquired brain injury since it is mostly an invisible deficit for society, yet a very limiting impairment for survivors.
