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183 THE COMPLEXITY OF DUAL-TASKING AFFECTS GAIT VARIABILITY IN PEOPLE WITH MILD COGNITIVE IMPAIRMENT
Posters / Parkinsonism and Related Disorders 16S1 (2010) S11–S86
rather than stop walking they adapt and slow down. All participants perceived walking and avoiding moving obstacles (i.e. crowds, dogs) as difficult supporting the growing use of functionally relevant DTs (Gerin-Lajoie et al. 2006). Conclusion: DT tests should be more functionally relevant to older people’s activities. Acknowledgements: Funding-The University of Jordan. Data collection-Fiona Cowan. Reference(s) Gerin-Lajoie et al. (2006). Gait and Posture, 24: 364–369. Lundin-Olsson et al. (1997). Lancet, 349(9052): 617. Swanenburg et al. (2008). BMC Musculoskeletal Disorders, 9: 162.
183 THE COMPLEXITY OF DUAL-TASKING AFFECTS GAIT VARIABILITY IN PEOPLE WITH MILD COGNITIVE IMPAIRMENT S. Muir1 , M. Speechley2 , M. Borrie1 , M. Montero-Odasso1 . 1 Geriatric Medicine, University of Western Ontario, Parkwood Hospital, 2 Epidemiology & Biostatistics, University of Western Ontario, London, ON, Canada Background and Aims: Gait variability (G-var), stride-to-stride time variation, depends on brain cortical control and is a sensitive way to quantify locomotion. The effect of different dual-task challenges on gait in people with Mild Cognitive Impairment (MCI) has not been evaluated. Our aim was to assess if dual-task challenges with increasing complexity affect G-var more in people with MCI compared to normal controls. Methods: Cross-sectional study of 48 people with MCI and 25 agematched normal controls from the Memory Clinic at University of Western Ontario. Gait variables were assessed under single (usual walking) and dual tasks (naming animals and subtracting serials sevens), using the GAITRite® System. Coefficients of variation were calculated to quantify G-var. Comparisons within and between groups were performed using repeated measures ANOVA and ttests respectively. Results: A statistically significant interaction in favour of MCI over controls was found across walking tests with increasing G-var (p = 0.0165). A dose–response relationship was found with increasing dual-task complexity. The magnitude of increase on G-var was greater for MCI (2.2% to 10.1%) than control group (1.9% to 3.7%). Gait velocity decreased across increasing dual-task complexity in each group (p < 0.0001). Conclusions: Dual-task load significantly increased G-var in the MCI group compared with controls. This effect was larger than changes seen on gait velocity. These findings suggest the complexity of dual-tasks affect gait due to a cortical brain resource limitation, particularly in people with MCI. Complex task challenges may provide a clinical methodology to detect people at higher risk of developing dementia. 184 DUAL-TASKING WHILE WALKING AND SUBCORTICAL HYPERINTENSITIES IN ALZHEIMER’S DISEASE AND AGING N. Nadkarni1,2 , J. Ramirez1 , C. Scott3 , K. Honjo3 , B. Levine4 , W. Mcilroy5 , S. Black1,2 . 1 Institute of Medical Science, University of Toronto, 2 Department of Medicine, 3 Sunnybrook Health Sciences Centre, 4 Department of Psychology, University of Toronto, Toronto, 5 Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada Background and Aim: Subcortical hyperintensities (SH), commonly seen on MRI in older adults, indicate underlying vascular disease and are associated with cognitive and gait impairment. Their association with dual-tasking during walking in healthy older adults and Alzheimer Disease (AD) patients is unclear and was investigated in this study. Methods: Cadence on treadmill and speed–accuracy-tradeoff (SAT) on two working memory tasks (x-task and 1-back), were measured
S53
during single- and dual-tasking in AD patients and normal controls (NC). MRI scans, performed within six-months, were semiautomatically processed to quantify frontal-basal ganglia, occipitalparietal and total SH volumes in correlation with SAT and cadence changes while dual-tasking. Results: AD group (n = 15) differed from NC (n = 21) only on MMSE (24 vs 29, p < 0.01) and gait-velocity (0.9 m/s vs 1.2 m/s, p < 0.01). In AD patients, changes in cadence on the x-task and 1-back task correlated significantly with total SH volumes (r = −0.5, p = 0.01; r = −0.6, p = 0.007 respectively), frontal-basal SH (r = −0.6, p ≤ 0.01 for each), and occipital-parietal SH (r = −0.5, p = 0.04; r = −0.5, p = 0.02 respectively). Amongst these, the frontal-basal ganglia SH volume best predicted dual-tasking costs on cadence [F(1,14) = 6.3, R = 0.6, p = 0.02 (x-task); F(1,14) = 8.4, R = 0.6, p = 0.01 (1-back)]. Dual-task costs on cadence and total or regional SH volume in NC including other correlations were not significant. Conclusions: SH severity, specifically in the frontal-basal regions, is associated with gait changes but not cognitive performance while dual-tasking in AD, possibly related to their adverse effects on executive functioning in AD. Measures of subcorticalischemic vascular disease should be considered in studies on dualtasking in AD. 185 DUAL-TASK PROGRAM TRAINING IN PATIENTS WITH ACQUIRED BRAIN INJURY 1 S. Pajares1 , C. Gonzalez ´ 1 , O. Robles2 , P. Casado1 , A. Gomez ´ , C. Cuenca3 , M. Ramiro3 , L. Hita4 , E. Villar4 , R. Fernandez4 . 1 Physical Medicine and Rehabilitation, 2 Neuropsychologist, CEADAC, 3 Physical Medicine and Rehabilitation, Hospital Cl´ınico San Carlos, 4 Physiotherapy, CEADAC, Madrid, Spain
Objective: To compare the effect of 2 different trainings on dualtask balance in patients with acquired brain injury. Material and Methods: A double-blind, randomized controlled trial was performed. Participants: Patients between 18 and 50 years old with acquired brain injury and balance disorders. Exclusion criteria: Neurological or musculoskeletal impairments previous to the acquired brain injury, speech disorders which impeded training, unable to stand with open eyes on an uneven surface (foam) and unable to walk without external devices, less than 6 on the Rancho Los Amigos Scale. Interventions: Patients were randomly assigned to 1 of 2 interventions: single-task training or dual-task training. Patients received a 30-minute group training session, 3 times a week during 4 weeks. Measures: Berg Scale and ABD Scale (Activities-specific Balance Confidence Scale) measurements were collected at baseline and after training. Balance was also analyzed with a postural measurement system (NedSVE/IBV, version 5.0.beta). Results and Conclusions: The first results show an objectives and parameters improvement on balance in more than 80% of patients. It’s too soon to find significant differences between the single-task training and dual-task training; we will continue to increase the sample.
rather than stop walking they adapt and slow down. All participants perceived walking and avoiding moving obstacles (i.e. crowds, dogs) as difficult supporting the growing use of functionally relevant DTs (Gerin-Lajoie et al. 2006). Conclusion: DT tests should be more functionally relevant to older people’s activities. Acknowledgements: Funding-The University of Jordan. Data collection-Fiona Cowan. Reference(s) Gerin-Lajoie et al. (2006). Gait and Posture, 24: 364–369. Lundin-Olsson et al. (1997). Lancet, 349(9052): 617. Swanenburg et al. (2008). BMC Musculoskeletal Disorders, 9: 162.
183 THE COMPLEXITY OF DUAL-TASKING AFFECTS GAIT VARIABILITY IN PEOPLE WITH MILD COGNITIVE IMPAIRMENT S. Muir1 , M. Speechley2 , M. Borrie1 , M. Montero-Odasso1 . 1 Geriatric Medicine, University of Western Ontario, Parkwood Hospital, 2 Epidemiology & Biostatistics, University of Western Ontario, London, ON, Canada Background and Aims: Gait variability (G-var), stride-to-stride time variation, depends on brain cortical control and is a sensitive way to quantify locomotion. The effect of different dual-task challenges on gait in people with Mild Cognitive Impairment (MCI) has not been evaluated. Our aim was to assess if dual-task challenges with increasing complexity affect G-var more in people with MCI compared to normal controls. Methods: Cross-sectional study of 48 people with MCI and 25 agematched normal controls from the Memory Clinic at University of Western Ontario. Gait variables were assessed under single (usual walking) and dual tasks (naming animals and subtracting serials sevens), using the GAITRite® System. Coefficients of variation were calculated to quantify G-var. Comparisons within and between groups were performed using repeated measures ANOVA and ttests respectively. Results: A statistically significant interaction in favour of MCI over controls was found across walking tests with increasing G-var (p = 0.0165). A dose–response relationship was found with increasing dual-task complexity. The magnitude of increase on G-var was greater for MCI (2.2% to 10.1%) than control group (1.9% to 3.7%). Gait velocity decreased across increasing dual-task complexity in each group (p < 0.0001). Conclusions: Dual-task load significantly increased G-var in the MCI group compared with controls. This effect was larger than changes seen on gait velocity. These findings suggest the complexity of dual-tasks affect gait due to a cortical brain resource limitation, particularly in people with MCI. Complex task challenges may provide a clinical methodology to detect people at higher risk of developing dementia. 184 DUAL-TASKING WHILE WALKING AND SUBCORTICAL HYPERINTENSITIES IN ALZHEIMER’S DISEASE AND AGING N. Nadkarni1,2 , J. Ramirez1 , C. Scott3 , K. Honjo3 , B. Levine4 , W. Mcilroy5 , S. Black1,2 . 1 Institute of Medical Science, University of Toronto, 2 Department of Medicine, 3 Sunnybrook Health Sciences Centre, 4 Department of Psychology, University of Toronto, Toronto, 5 Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada Background and Aim: Subcortical hyperintensities (SH), commonly seen on MRI in older adults, indicate underlying vascular disease and are associated with cognitive and gait impairment. Their association with dual-tasking during walking in healthy older adults and Alzheimer Disease (AD) patients is unclear and was investigated in this study. Methods: Cadence on treadmill and speed–accuracy-tradeoff (SAT) on two working memory tasks (x-task and 1-back), were measured
S53
during single- and dual-tasking in AD patients and normal controls (NC). MRI scans, performed within six-months, were semiautomatically processed to quantify frontal-basal ganglia, occipitalparietal and total SH volumes in correlation with SAT and cadence changes while dual-tasking. Results: AD group (n = 15) differed from NC (n = 21) only on MMSE (24 vs 29, p < 0.01) and gait-velocity (0.9 m/s vs 1.2 m/s, p < 0.01). In AD patients, changes in cadence on the x-task and 1-back task correlated significantly with total SH volumes (r = −0.5, p = 0.01; r = −0.6, p = 0.007 respectively), frontal-basal SH (r = −0.6, p ≤ 0.01 for each), and occipital-parietal SH (r = −0.5, p = 0.04; r = −0.5, p = 0.02 respectively). Amongst these, the frontal-basal ganglia SH volume best predicted dual-tasking costs on cadence [F(1,14) = 6.3, R = 0.6, p = 0.02 (x-task); F(1,14) = 8.4, R = 0.6, p = 0.01 (1-back)]. Dual-task costs on cadence and total or regional SH volume in NC including other correlations were not significant. Conclusions: SH severity, specifically in the frontal-basal regions, is associated with gait changes but not cognitive performance while dual-tasking in AD, possibly related to their adverse effects on executive functioning in AD. Measures of subcorticalischemic vascular disease should be considered in studies on dualtasking in AD. 185 DUAL-TASK PROGRAM TRAINING IN PATIENTS WITH ACQUIRED BRAIN INJURY 1 S. Pajares1 , C. Gonzalez ´ 1 , O. Robles2 , P. Casado1 , A. Gomez ´ , C. Cuenca3 , M. Ramiro3 , L. Hita4 , E. Villar4 , R. Fernandez4 . 1 Physical Medicine and Rehabilitation, 2 Neuropsychologist, CEADAC, 3 Physical Medicine and Rehabilitation, Hospital Cl´ınico San Carlos, 4 Physiotherapy, CEADAC, Madrid, Spain
Objective: To compare the effect of 2 different trainings on dualtask balance in patients with acquired brain injury. Material and Methods: A double-blind, randomized controlled trial was performed. Participants: Patients between 18 and 50 years old with acquired brain injury and balance disorders. Exclusion criteria: Neurological or musculoskeletal impairments previous to the acquired brain injury, speech disorders which impeded training, unable to stand with open eyes on an uneven surface (foam) and unable to walk without external devices, less than 6 on the Rancho Los Amigos Scale. Interventions: Patients were randomly assigned to 1 of 2 interventions: single-task training or dual-task training. Patients received a 30-minute group training session, 3 times a week during 4 weeks. Measures: Berg Scale and ABD Scale (Activities-specific Balance Confidence Scale) measurements were collected at baseline and after training. Balance was also analyzed with a postural measurement system (NedSVE/IBV, version 5.0.beta). Results and Conclusions: The first results show an objectives and parameters improvement on balance in more than 80% of patients. It’s too soon to find significant differences between the single-task training and dual-task training; we will continue to increase the sample.