Motor function and cognition : aspects on gait and balance

Introduction: Cognitive dysfunction and dementia are linked to physical disability and are the major cause of dependency and institutionalization in the elderly. Physical therapists deal with disability yet little clinical and research attention has been given to the physical disability experienced in people with cognitive dysfunction.

Aim: The overall purpose with this thesis was to investigate and characterize motor function with special reference to gait and balance in people with mild cognitive decline of different etiology.

Methods: In the first study static and dynamic balance, basic mobility as well as level of physical activity was assessed and compared between healthy older subjects and subjects with mild Alzheimer's disease. In the second study data came from all subjects who were referred to a memory clinic for cognitive symptoms and suspected dementia and had had an evaluation of a physical therapist. After a thorough diagnostic evaluation the subjects were divided into four groups according to diagnosis. Motor function was compared between subjects, who were free of cognitive disorder, had mild cognitive impairment, or mild Alzheimer's disease or other dementia diseases, respectively. In the third study the effect of dual-task performance on gait was examined and compared between subjects with and without cognitive impairment. Finally the role of physical activity level on motor function and quality of life was evaluated in elderly subjects with different degrees of age related white matter changes in the brain.

Results: The main result of this work show that subjects with mild stages of dementia have poorer balance performance, are slower in basic mobility and have decreased walking speed. Subjects at mild stages of dementia tend to cease activities that place demands on initiative and planning. Dual-task performance seems to cause additional decrements in motor function in subjects with cognitive disability. Co-morbidities like vascular risk factors may play an important role in the development of disability in motor function in subjects with cognitive disability.

Conclusion: Motor function is impaired already at mild stages of dementia. Physical therapists should encourage physical activity in subjects with as well as without cognitive impairment in order to prevent further progress of disability and in order to prevent risk factors that contribute to motor and disability later in life. Physical therapists should be aware of the implications of difficulties in dual-task situations that subjects with cognitive disability may have and they should also be aware of the potential effect of dysexecutive function on the ability to follow a treatment program and advise on physical activity.

List of scientific papers

I. Pettersson AF, Engardt M, Wahlund LO (2002). "Activity level and balance in subjects with mild Alzheimers disease." Dement Geriatr Cogn Disord 13(4): 213-6.
https://doi.org/10.1159/000057699

II. Pettersson AF, Olsson E, Wahlund LO (2005). "Motor function in subjects with mild cognitive impairment and early Alzheimers disease. " Dement Geriatr Cogn Disord 19(5-6): 299-304.
https://doi.org/10.1159/000084555

III. Pettersson AF, Olsson E, Wahlund LO (2005). "The effect of divided attention on gait in subjects with and without cognitive impairment." J Geriatric Psychiatry and Neurology. [Accepted]
https://doi.org/10.1177/0891988706293528

IV. Pettersson AF, Crisby M, Amberla K, Bazner H, Olsson E, Wahlund LO (2005). "Activity level in older people with leukoaraiosis and its influence on motor performance and quality of life." [Submitted]