Running head: INFLUENCE OF STIMULI ON STROKE RECOVERY 1. Influence of Auditory and Visual Stimuli on Stroke Recovery in the Aging Population

Transcription

1 Running head: INFLUENCE OF STIMULI ON STROKE RECOVERY 1 Influence of Auditory and Visual Stimuli on Stroke Recovery in the Aging Population Matthew Nare California State University, Long Beach

2 INFLUENCE OF STIMULI ON STROKE RECOVERY 2 Specific Aims The purpose of this research is to compare the effects of auditory or auditory and visual stimuli on cognitive recovery in older post-stroke patients. The objective of this study is to examine if exposure to certain stimuli are more or less appropriate for post-stroke participants depending on the hemisphere that suffered the stroke. For this research, the auditory stimuli will be self-selected music and the combined auditory and visual stimuli will be self-selected television viewing. This research examines the effects on the participants ability to follow verbal instructions on a cognitive task as demonstrated by the completion of the tower of Hanoi. Hypothesis 1: All participants will see improvement in their ability to follow verbal instructions with exposure to either form of stimuli. Hypothesis 2: Participants receiving the combination of auditory and visual stimuli will see more improvement in their ability to follow verbal instructions compared to the participants receiving only auditory stimuli. Alternative hypothesis: Participants receiving only auditory stimuli will see more improvement in their ability to follow verbal instructions compared to the participants receiving auditory and visual stimuli. The alternative hypothesis was selected due to the possibility that the combination of the auditory and visual stimuli will not assist in decreasing the task completion time. Potentially, additional stimuli may inhibit the participants ability to focus on the task objective and cause sensory overstimulation. Furthermore, since the use of combined auditory and visual stimuli in stroke recovery is not widely studied, this current study may add value to stroke rehabilitation even if some of the hypotheses fail to be supported. Background and Significance

3 INFLUENCE OF STIMULI ON STROKE RECOVERY 3 Stroke is the leading cause of chronic adult disability and third leading cause of death in North America (Corbett & Murphy, 2009). A stroke is caused by the interruption of blood flow to the brain resulting in damage to the neurons in the brain (Corbett & Murphy, 2009). If the stroke is not fatal, the person is often left with physical disabilities such as lacking arm or leg movement. Furthermore, there may be potential psychological, emotional, and cognitive disabilities such as depression, emotional lability, and various processing delays. With these substantial physical, cognitive, and emotional changes there is often a change a person s identity and perception of self-worth changes which influences their resolve to attempt the road to recovery (Gallagher, 2011). Past research has suggested that music can improve the cognitive recovery of post-stroke patients as well as maintain a more positive mood (Särkämö, Tervaniemi, Laitinen, Forsblom, Soinila, 2008). Participants listening to music performed better on memory, cognition, and attention tests compared to participants listening to audio books or participants not listening to anything (Särkämö et al., 2008). Previous research has suggested that training with music also improves recovery of motor skills as well as increase effectiveness of treatment (Schneider, Münte, Rodriguez-Fornells, Sailer, & Altenmüller, 2010). Särkãmo, et al. (2008) researched the effects of music over a longer period time by testing over six months. This current study is significant in its early examination of post-stroke auditory attention and learning within the aging population. In this study, the aging population is defined as participants with a minimum age of 65 years. Studying the cognitive recovery of patients 65 years or older is important because this age group was studied for the comparison of incidence and mortality for countries around the world (Thrift, Cadilhac, Thayabaranathan, Howard, Howard, et al., 2014).

4 INFLUENCE OF STIMULI ON STROKE RECOVERY 4 There are three stages of acceptance involved in post-stroke recovery. Those three stages are realizing the effects of the stroke will not resolve on their own, making a personal commitment to get better, and then actively participating in their rehabilitation (Gallagher, 2011). However, it is difficult to create national strategies to address stroke recovery because of the lack of easily accessible comparable data (Thrift, et al., 2014). In addition, it is important to note that it is highly improbable that two strokes present exactly the same. By improving our knowledge of how different stimuli influences recovery time, we can create more efficiently create an effective treatment programs to return patients as close as possible to normal functioning. Not only would we be able to get post-stroke patients as close as possible to their baseline, but we would also be able to shorten the recovery timetable. Future research can facilitate the development of strategies for stroke rehabilitation by continuing to examine the positive benefits of music in early examination of post-stroke patients. Future research should also evaluate the effects of multimodal (combination of auditory and visual) stimulation in post-stroke patients of other age groups as continuing to investigate the effects of multimodal stimuli in post-stroke patients 65 years or older over a longer trajectory. Research Design and Methods Sixty post-stroke patients (30 male and 30 female) currently under acute medical management are recruited to participate in this study. Thirty patients will be recovering from left hemisphere stroke and 30 patients will be recovering from a right hemisphere stroke. Criteria for inclusion include: (1) Participants must not have uncorrected hearing deficits (e.g. hearing aids are acceptable), (2) Participants must not have uncorrected eyesight deficits (e.g. eyeglasses are acceptable), (3) Participants must be between one to two weeks post-stroke, (4) Participants must

5 INFLUENCE OF STIMULI ON STROKE RECOVERY 5 be minimally 65 years of age, (5) patients cannot have a history of prior strokes or brain damage, and (6) participants will be classified as having a moderate stroke. A trained professional will test each prospective participant using the National Institute of Health Stroke Scale (NIHSS) to ensure participants have similar cognitive and motor functioning baselines. Participants must be classified as a moderate stroke according to the NIHSS by receiving a score of 5-14 on a scale of 0-42 on a variety of cognitive and motor tests (Gajurel, Dhungana, Parajuli, Karn, Rajbhandari, Kafle, & Oli, 2014). Fifteen left hemisphere and 15 right hemisphere post-stoke participants will be combined to make Condition A. Fifteen left hemisphere and 15 right hemisphere post-stoke patients will be combined to make Condition B. Condition A will experience only the auditory stimulus (selfselected music). Condition B will experience the auditory and visual stimulus (self-selected television viewing). Participants will be informed of the purpose of this research and sign an informed consent before involvement in this study. The participants will participate in a timed pre-test and posttest separated by one week of attempting to complete the five-ring tower of Hanoi. A research assistant with working knowledge of the requirements of the task will begin timing when the participant touches the first ring and stop timing when the last component is in place. Prior to receiving any stimulation (self-selected music or television viewing) participants will complete the timed pre-test. Participants unable to complete the task will be unable to continue in the study and will not be allowed to participate in the post-test. During the week, participants from Condition A will be able to listen to self-selected music and the participants from Condition B will be able to watch self-selected television viewing for two hours per day. The hours will be split between morning and afternoon.

6 INFLUENCE OF STIMULI ON STROKE RECOVERY 6 Following one week of daily stimuli (self-selected music or television viewing) both groups will again receive verbal instructions on how to complete the task of the Tower of Hanoi. Predicted Results One predication for the results of this study is that all of the participants will have a decrease in the time it takes to complete the tower of Hanoi on the post-test compared to their pre-test time. It is predicted that the completion times will decrease reflecting any amount of cognitive recovery. However, it is possible that the cognitive recovery may not be a direct result of the stimuli experienced. A second prediction is that post-stroke participants that received the combination of the auditory and visual stimulation will have a greater statistically significant decrease in their completion time compared to the participants that only received auditory stimuli. Potentially, the participants who received both auditory and visual stimuli will perform better as a result of facilitating cognitive recovery through a wider array of neural pathways. The participants that only received auditory stimuli will have less exposure to different types of cues for facilitating cognitive recovery. The decrease in completion time suggests that the patients were able to listen and understand the directions with more success on the post-test compared to the pre-test. These results imply that the patients improved in their problem solving and verbal attention. It is possible that the participants selection of music or television viewing and age can influence the accuracy of the results of this study. As previously stated, it is also possible that combining auditory and visual stimulation early on in stroke recovery may result in sensory overstimulation and result in poor participant performance.

7 INFLUENCE OF STIMULI ON STROKE RECOVERY 7 References Corbett, D., & Murphy, T. (2009). Plasticity during stroke recovery: From synapse to behaviour. Nature Reviews Neuroscience, 10(12), Gajurel, B. P., Dhungana, K., Parajuli, P., Karn, R., Rajbhandari, R., Kafle, D., & Oli, K. K. (2014). The National Institute of Health Stroke Scale Score and Outcome in Acute Ischemic Stroke. Journal Of Institute Of Medicine, 36(3), Gallagher, P. (2011). Becoming normal: A grounded theory study on the emotional process of stroke recovery. Canadian Journal of Neuroscience Nursing, 33(3), 24. Särkämö, T., Tervaniemi, M., Laitinen, S., Forsblom, A., Soinila, S., et al. (2008). Music listening enhances cognitive recovery and mood after middle cerebral artery stroke. Brain, 131(3), Schneider, S., Münte, T., Rodriguez-Fornells, A., Sailer, M., & Altenmüller, E. (2010). Musicsupported training is more efficient than functional motor training for recovery of fine motor skills in stroke patients. Music Perception: An Interdisciplinary Journal, 27(4), Thrift, A., Cadilhac, D., Thayabaranathan, T., Howard, G., Howard, V., et al. (2014). Global stroke statistics. International Journal of Stroke, 9(1), 6-18.

8 INFLUENCE OF STIMULI ON STROKE RECOVERY 8 Right Hemisphere Left Hemisphere Mean Task Completion Time (sec.) Auditory Stimulation Type Auditory and Visual Figure 1: Mean task completion time in second for auditory (Condition A) and auditory and visual (Condition B) conditions before participants received any stimulation (pre-test).

9 INFLUENCE OF STIMULI ON STROKE RECOVERY 9 Right Hemisphere Left Hemisphere Mean Task Completion Time (sec.) Auditory Stimulation Type Auditory and Visual Figure 2: Mean task completion time in seconds for auditory (Condition A) and auditory and visual (Condition B) conditions after participants received daily stimulation for one week (post-test).