AN EXAMINATION OF THE ATTENTIONAL DEMANDS OF WALKING AND STANDING IN INDIVIDUALS DIAGNOSED WITH A CEREBROVASCULAR ACCIDENT (CVA).
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Introduction: In 1994 approximately 3 million Americans had a cerebrovascular accident (CVA) at some point during their life. According to the National Stroke Association, the current estimate of the number of strokes per year in the United States is 730,000. Following a stroke, the person will experience many neurological changes resulting in physical and/or cognitive impairments. When assessing and treating a person post-CVA, physical therapists will need to consider how these impairments may affect this person.
The project focused on exploring the attentional impairments in people post-CVA. By researching the effects of a CVA on attention, we can provide information to assist physical therapists with treatment interventions and methods of patient instruction. If people post-CVA utilize greater attentional resources for standing and ambulation, they may experience enhanced learning if physical therapy instructions are simplified, tasks kept uncomplicated, and distractions are minimized. Understanding the attentional demands of people post-CVA may enable us to expedite their recovery and to safely challenge patients to progress beyond their current level of function.
Purpose: The purpose of this study is to determine if there are variations in the voice reaction times of individuals post-CVA, during standing and ambulation, compared to individuals without a history of neurological infarct. In addition, comparisons of voice reaction time were made between subjects with a left hemisphere CVA, subjects with a right hemisphere CVA, and subjects with a global CVA. By determining if there are differences in reaction time, a better understanding of the factors affecting function can be achieved.
Hypotheses: We hypothesized that the attention required for ambulation and standing for people post-CVA will be greater than that of people without neurologic infarct. It is also our hypothesis that the attention required for standing is less than that for ambulating in all types of subjects. Finally, we hypothesize that when comparing people with a global, right, or left hemisphere CVA, voice reaction time will remain the same.
Subjects: Seventeen subjects with a history of CVA (x= 65.7 ± 8.4 yrs) were recruited from MossRehab, 17 age matched subjects, (x= 67.2 ± 6.7 yrs) and 17 young adult subjects (x= 24.4 ± 2.8 yrs) without a prior history of CVA were recruited from the local community.
Methods: A dual task methodology was used to examine voice reaction time (VRT). The primary task required the subjects to perform a functional activity consisting of either: sitting, standing, or walking. The secondary task required the subjects to respond to an auditory stimulus by saying the letter “B”.
Data Analysis: A repeated measures ANOVA was used to examine between and within subject differences in VRT. Tukey’s HSD test was utilized for post hoc analysis for any significant main effects and for any significant group by condition interactions.
Results: Statistically significant differences in VRT for the main effects of group were found between the subjects with a history of CVA and the control subjects. Those with a history of a CVA had a significantly slower VRT than those without a history of neurological infarct. No significant difference in VRT was found for the main effect of task. Statistically significant differences were found for the interaction of task with group. In sitting, the age matched controls had a faster VRT than those in the bilateral and right CVA groups; the young adults were faster than the age matched control subjects. For standing, the young adult group and the age matched control group were faster than all subjects post CVA. For walking, the young adult and age matched control groups were faster than those individuals in the right CVA group.
Conslusions: Based on the results of this study, the subjects post CVA have a longer VRT than age matched and younger non-disabled subjects. This is likely a result of an increase in cognitive processing time, leading to a decrease in response time. The increase in cognitive processing time may be due in part to the effects of the central nervous system lesion. Alternatively, the increase in cognitive processing time may be associated with the increase in postural demands of the task and the subsequent imposition on cognitive processing resources. Subjects post CVA may need to devote greater attentional or cognitive processing resources to the maintenance of postural stability than the age matched or young control subjects. More research will be needed to compare the differences in cognitive processing during functional activities according to the location of the central nervous system lesion.Research completed as part of the requirements for the Master of Science Degree in Physical Therapy, Institute for Physical Therapy Education, Widener University, Chester, PA. Conducted in association with the Department of Physical Therapy, MossRehab Hospital, Philadelphia, PA. Accepted for poster presentation at the 2001 Combined Sections Meeting, San Antonio, TX.