human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVES To investigate longitudinal associations between changes in brain structure and gait decline  . DESIGN Longitudinal . SETTING Population -based Tasmanian Study of Cognition and Gait . PARTICIPANTS Two hundred twenty-five individuals aged 60 to 86 ( mean age 71.4 ± 6.8 ) r and omly selected from the electoral roll with baseline and follow-up data . MEASUREMENTS Volumes of gray matter , white matter , hippocampi , and white matter lesions ( WML ) were estimated using automated segmentation from magnetic resonance imaging ( MRI ) .  Gait variables were measured using a computerized walkway . Linear regression was used to estimate the association between change in brain MRI measures and change in gait . Time between measurements , age , sex , BMI , education level , total intracranial volume , baseline infa rcts , and medical history were used as baseline covariates . RESULTS Mean follow-up was 30.6 months . White matter atrophy was associated with a decline in gait speed ( P = .001 ) , step length ( P = .005 ) , and cadence ( P = .001 ) . WML progression was associated with a decline in gait speed ( P = .04 ) , and its association with decline in step length was stronger with greater baseline age ( P for interaction = .04 ) . Hippocampal atrophy was associated with a decline in gait speed ( P = .006 ) and step length ( P = .001 ) . Total gray matter atrophy was associated with decline in cadence in those with cerebral infa rcts ( P for interaction = .02 ) . CONCLUSION These are the first longitudinal data demonstrating the relative contributions of brain atrophy and WML progression to gait decline in older people . Effect modification according to age and infa rcts suggests a contribution of reduced physiological and brain reserve . Interventions targeting brain health may be important in preventing mobility decline in older people CONTEXT Reorganization in central motor networks occurs during early recovery from hemiparetic stroke . In chronic stroke survivors , specific rehabilitation therapy can improve upper extremity function . OBJECTIVE To test the hypothesis that in patients who have chronic motor impairment following stroke , specific rehabilitation therapy that improves arm function is associated with reorganization of cortical networks . DESIGN , SETTING , AND PATIENTS A r and omized controlled clinical trial conducted in a US ambulatory rehabilitation program with 21 patients ( median [ IQR ] , 50.3 [ 34.8 - 77.3 ] months after unilateral stroke ) . Data were collected between 2001 and 2004 . INTERVENTIONS Patients were r and omly assigned to bilateral arm training with rhythmic auditory cueing ( BATRAC ) ( n = 9 ) or st and ardized dose-matched therapeutic exercises ( DMTE ) ( n = 12 ) . Both were conducted for 1 hour , 3 times a week , for 6 weeks . MAIN OUTCOME MEASURES Within 2 weeks before and after the intervention , brain activation during elbow movement assessed by functional magnetic resonance imaging ( fMRI ) and functional outcome assessed using arm function scores . RESULTS Patients in the BATRAC group but not in the DMTE group increased hemispheric activation during paretic arm movement ( P = .03 ) . Changes in activation were observed in the contralesional cerebrum and ipsilesional cerebellum ( P = .009 ) . BATRAC was associated with significant increases in activation in pre central ( P<.001 ) and post central gyri ( P = .03 ) and the cerebellum ( P<.001 ) , although 3 BATRAC patients showed no fMRI changes . Considering all patients , there were no differences in functional outcome between groups . When only BATRAC patients with fMRI response were included ( n = 6 ) , BATRAC improved arm function more than DMTE did ( P = .02 ) . CONCLUSIONS These preliminary findings suggest that BATRAC induces reorganization in contralesional motor networks and provide biological plausibility for repetitive bilateral training as a potential therapy for upper extremity rehabilitation in hemiparetic stroke Visual and auditory feedback cues have been shown to improve gait and balance in patients with movement disorders , such as Parkinson 's disease and multiple sclerosis . Subsequently , closed-loop virtual reality was used to enhance the gait improvement effect of such cues . Objectives : To study the effects of gait training with visual and auditory feedback cues on the walking abilities of patients with gait disorders due to cerebral palsy . Methods : Visual and auditory feedback cues were generated by a wearable accelerometry-driven device . Ten r and omly selected patients with gait disorders due to cerebral palsy trained with visual feedback cues while ten such patients trained with auditory feedback cues . Baseline performance ( walking speed and stride length along a 10 m straight track ) was measured before device use . Following 20min training with the device , performance without the device was measured again and compared to the baseline performance . Results : For patients training with visual feedback , the average improvement in walking speed was 21.70%+/−36.06 % and in stride length 8.72%±9.47 % . For patients training with auditory feedback , average improvement in walking speed was 25.43%±28.65 % and in stride length 13.58%±13.10 % . Conclusion : Visual and auditory feedback cues can improve gait parameters in patients with gait disorders due to cerebral palsy OBJECTIVES To evaluate the effect of a novel divided attention task-walking under auditory constraints-on gait performance in older adults and to determine whether this effect was moderated by cognitive status . DESIGN Validation cohort . SETTING General community . PARTICIPANTS Ambulatory older adults without dementia ( N=104 ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES In this pilot study , we evaluated walking under auditory constraints in 104 older adults who completed 3 pairs of walking trials on a gait mat under 1 of 3 r and omly assigned conditions : 1 pair without auditory stimulation and 2 pairs with emotionally charged auditory stimulation with happy or sad sounds . RESULTS The mean age of subjects was 80.6±4.9 years , and 63 % ( n=66 ) were women .  The mean velocity during normal walking was 97.9±20.6cm/s , and the mean cadence was 105.1±9.9 steps/min . The effect of walking under auditory constraints on gait characteristics was analyzed using a 2-factorial analysis of variance with a 1-between factor ( cognitively intact and minimal cognitive impairment groups ) and a 1-within factor ( type of auditory stimuli ) . In both happy and sad auditory stimulation trials , cognitively intact older adults ( n=96 ) showed an average increase of 2.68cm/s in gait velocity ( F1.86,191.71=3.99 ; P=.02 ) and an average increase of 2.41 steps/min in cadence ( F1.75,180.42=10.12 ; P<.001 ) as compared with trials without auditory stimulation . In contrast , older adults with minimal cognitive impairment ( Blessed test score , 5 - 10 ; n=8 ) showed an average reduction of 5.45cm/s in gait velocity ( F1.87,190.83=5.62 ; P=.005 ) and an average reduction of 3.88 steps/min in cadence ( F1.79,183.10=8.21 ; P=.001 ) under both auditory stimulation conditions . Neither baseline fall history nor performance of activities of daily living accounted for these differences . CONCLUSIONS Our results provide preliminary evidence of the differentiating effect of emotionally charged auditory stimuli on gait performance in older individuals with minimal cognitive impairment compared with those without minimal cognitive impairment . A divided attention task using emotionally charged auditory stimuli might be able to elicit compensatory improvement in gait performance in cognitively intact older individuals , but lead to decompensation in those with minimal cognitive impairment . Further investigation is needed to compare gait performance under this task to gait on other dual-task paradigms and to separately examine the effect of physiological aging versus cognitive impairment on gait during walking under auditory constraints AIM The aim of this study was to evaluate the interrater reliability and convergent validity of the American Academy for  Cerebral Palsy and Developmental Medicine  's ( AACPDM ) methodology for conducting systematic review s ( group design studies ) . METHOD Four clinicians independently rated 24 articles for the level of evidence and conduct using AACPDM methodology . Study conduct was also assessed using the Effective Public Health Practice Project scale . Raters were r and omly assigned to one of two pairs to resolve discrepancies . The level of agreement between individual raters and pairs was calculated using kappa ( α=0.05 ) and intraclass correlations ( ICCs ; α=0.05 ) . Spearman 's rank correlation coefficient was calculated to evaluate the relationship between raters ' categorization of quality categories using the two tools . RESULTS There was acceptable agreement between raters ( κ=0.77 ; p<0.001 ; ICC=0.90 ) and between assigned pairs ( κ=0.83 ; p<0.001 ; ICC=0.96 ) for the level of evidence ratings . There was acceptable agreement between pairs for four of the seven conduct questions ( κ=0.53 - 0.87 ) . ICCs ( all raters ) for conduct category ratings ( weak , moderate , and strong ) also indicated good agreement ( ICC=0.76 ) . Spearman 's rho indicated a significant positive correlation for the overall quality category comparisons of the two tools ( 0.52 ; p<0.001 ) . CONCLUSIONS The AACPDM rating system has acceptable interrater reliability . Evaluation of its study quality ratings demonstrated reasonable agreement when compared with a similar tool Parkinson 's disease ( PD ) and basal ganglia dysfunction impair movement timing , which leads to gait instability and falls . Parkinsonian gait consists of r and om , disconnected stride times — rather than the 1/f structure observed in healthy gait— and this r and omness of stride times ( low fractal scaling ) predicts falling . Walking with fixed-tempo Rhythmic Auditory Stimulation ( RAS ) can improve many aspects of gait timing ; however , it lowers fractal scaling ( away from healthy 1/f structure ) and requires attention . Here we show that interactive rhythmic auditory stimulation reestablishes healthy gait dynamics in PD patients . In the experiment , PD patients and healthy participants walked with a ) no auditory stimulation , b ) fixed-tempo RAS , and c ) interactive rhythmic auditory stimulation . The interactive system used foot sensors and nonlinear oscillators to track and mutually entrain with the human 's step timing . Patients consistently synchronized with the interactive system , their fractal scaling returned to levels of healthy participants , and their gait felt more stable to them . Patients and healthy participants rarely synchronized with fixed-tempo RAS , and when they did synchronize their fractal scaling declined from healthy 1/f levels . Five minutes after removing the interactive rhythmic stimulation , the PD patients ' gait retained high fractal scaling , suggesting that the interaction stabilized the internal rhythm generating system and reintegrated timing networks . The experiment demonstrates that complex interaction is important in the (re)emergence of 1/f structure in human behavior and that interactive rhythmic auditory stimulation is a promising therapeutic tool for improving gait of PD patients Patients with Parkinson 's disease ( PD ) walk with a shortened stride length and high stride-to-stride variability , a measure associated with fall risk . Rhythmic auditory stimulation ( RAS ) improves stride length but the effects on stride-to-stride variability , a marker of fall risk , are unknown . The effects of RAS on stride time variability , swing time variability and spatial-temporal measures were examined during 100-m walks with the RAS beat set to 100 and 110 % of each subject 's usual cadence in 29 patients with idiopathic PD and 26 healthy age-matched controls . Carryover effects were also evaluated . During usual walking , variability was significantly higher ( worse ) in the patients with PD compared with the controls ( P < 0.01 ) . For the patients with PD , RAS at 100 % improved gait speed , stride length and swing time ( P < 0.02 ) but did not significantly affect variability . With RAS at 110 % , reductions in variability were also observed ( P < 0.03 ) and these effects persisted 2 and 15 min later . In the control subjects , the positive effects of RAS were not observed . For example , RAS increased stride time variability at 100 and 110 % . These results demonstrate that RAS enables more automatic movement and reduces stride-to-stride variability in patients with PD . Further , these improvements are not simply a by-product of changes in speed or stride length . After walking with RAS , there also appears to be a carryover effect that supports the possibility of motor plasticity in the networks controlling rhythmicity in PD and the potential for using RAS as an intervention to improve mobility and reduce fall risk It is commonly agreed that a functional dissociation with respect to the internal vs external control of movements exists for several brain regions . This has , however , only been tested in relation to the timing and preparation of motor responses , but not to ongoing movement control . Using functional magnetic resonance imaging ( fMRI ) , the present study addressed the neuroanatomical substrate of the internal-external control hypothesis by comparing regional brain activation for cyclical bimanual movements performed in the presence or absence of augmented visual feedback .  Subjects performed a bimanual movement pattern , either with the help of on-line visual feedback of 
    Output:
    
agent
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVES To investigate longitudinal associations between changes in brain structure and gait decline  . DESIGN Longitudinal . SETTING Population -based Tasmanian Study of Cognition and Gait . PARTICIPANTS Two hundred twenty-five individuals aged 60 to 86 ( mean age 71.4 ± 6.8 ) r and omly selected from the electoral roll with baseline and follow-up data . MEASUREMENTS Volumes of gray matter , white matter , hippocampi , and white matter lesions ( WML ) were estimated using automated segmentation from magnetic resonance imaging ( MRI ) .  Gait variables were measured using a computerized walkway . Linear regression was used to estimate the association between change in brain MRI measures and change in gait . Time between measurements , age , sex , BMI , education level , total intracranial volume , baseline infa rcts , and medical history were used as baseline covariates . RESULTS Mean follow-up was 30.6 months . White matter atrophy was associated with a decline in gait speed ( P = .001 ) , step length ( P = .005 ) , and cadence ( P = .001 ) . WML progression was associated with a decline in gait speed ( P = .04 ) , and its association with decline in step length was stronger with greater baseline age ( P for interaction = .04 ) . Hippocampal atrophy was associated with a decline in gait speed ( P = .006 ) and step length ( P = .001 ) . Total gray matter atrophy was associated with decline in cadence in those with cerebral infa rcts ( P for interaction = .02 ) . CONCLUSION These are the first longitudinal data demonstrating the relative contributions of brain atrophy and WML progression to gait decline in older people . Effect modification according to age and infa rcts suggests a contribution of reduced physiological and brain reserve . Interventions targeting brain health may be important in preventing mobility decline in older people CONTEXT Reorganization in central motor networks occurs during early recovery from hemiparetic stroke . In chronic stroke survivors , specific rehabilitation therapy can improve upper extremity function . OBJECTIVE To test the hypothesis that in patients who have chronic motor impairment following stroke , specific rehabilitation therapy that improves arm function is associated with reorganization of cortical networks . DESIGN , SETTING , AND PATIENTS A r and omized controlled clinical trial conducted in a US ambulatory rehabilitation program with 21 patients ( median [ IQR ] , 50.3 [ 34.8 - 77.3 ] months after unilateral stroke ) . Data were collected between 2001 and 2004 . INTERVENTIONS Patients were r and omly assigned to bilateral arm training with rhythmic auditory cueing ( BATRAC ) ( n = 9 ) or st and ardized dose-matched therapeutic exercises ( DMTE ) ( n = 12 ) . Both were conducted for 1 hour , 3 times a week , for 6 weeks . MAIN OUTCOME MEASURES Within 2 weeks before and after the intervention , brain activation during elbow movement assessed by functional magnetic resonance imaging ( fMRI ) and functional outcome assessed using arm function scores . RESULTS Patients in the BATRAC group but not in the DMTE group increased hemispheric activation during paretic arm movement ( P = .03 ) . Changes in activation were observed in the contralesional cerebrum and ipsilesional cerebellum ( P = .009 ) . BATRAC was associated with significant increases in activation in pre central ( P<.001 ) and post central gyri ( P = .03 ) and the cerebellum ( P<.001 ) , although 3 BATRAC patients showed no fMRI changes . Considering all patients , there were no differences in functional outcome between groups . When only BATRAC patients with fMRI response were included ( n = 6 ) , BATRAC improved arm function more than DMTE did ( P = .02 ) . CONCLUSIONS These preliminary findings suggest that BATRAC induces reorganization in contralesional motor networks and provide biological plausibility for repetitive bilateral training as a potential therapy for upper extremity rehabilitation in hemiparetic stroke Visual and auditory feedback cues have been shown to improve gait and balance in patients with movement disorders , such as Parkinson 's disease and multiple sclerosis . Subsequently , closed-loop virtual reality was used to enhance the gait improvement effect of such cues . Objectives : To study the effects of gait training with visual and auditory feedback cues on the walking abilities of patients with gait disorders due to cerebral palsy . Methods : Visual and auditory feedback cues were generated by a wearable accelerometry-driven device . Ten r and omly selected patients with gait disorders due to cerebral palsy trained with visual feedback cues while ten such patients trained with auditory feedback cues . Baseline performance ( walking speed and stride length along a 10 m straight track ) was measured before device use . Following 20min training with the device , performance without the device was measured again and compared to the baseline performance . Results : For patients training with visual feedback , the average improvement in walking speed was 21.70%+/−36.06 % and in stride length 8.72%±9.47 % . For patients training with auditory feedback , average improvement in walking speed was 25.43%±28.65 % and in stride length 13.58%±13.10 % . Conclusion : Visual and auditory feedback cues can improve gait parameters in patients with gait disorders due to cerebral palsy OBJECTIVES To evaluate the effect of a novel divided attention task-walking under auditory constraints-on gait performance in older adults and to determine whether this effect was moderated by cognitive status . DESIGN Validation cohort . SETTING General community . PARTICIPANTS Ambulatory older adults without dementia ( N=104 ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES In this pilot study , we evaluated walking under auditory constraints in 104 older adults who completed 3 pairs of walking trials on a gait mat under 1 of 3 r and omly assigned conditions : 1 pair without auditory stimulation and 2 pairs with emotionally charged auditory stimulation with happy or sad sounds . RESULTS The mean age of subjects was 80.6±4.9 years , and 63 % ( n=66 ) were women .  The mean velocity during normal walking was 97.9±20.6cm/s , and the mean cadence was 105.1±9.9 steps/min . The effect of walking under auditory constraints on gait characteristics was analyzed using a 2-factorial analysis of variance with a 1-between factor ( cognitively intact and minimal cognitive impairment groups ) and a 1-within factor ( type of auditory stimuli ) . In both happy and sad auditory stimulation trials , cognitively intact older adults ( n=96 ) showed an average increase of 2.68cm/s in gait velocity ( F1.86,191.71=3.99 ; P=.02 ) and an average increase of 2.41 steps/min in cadence ( F1.75,180.42=10.12 ; P<.001 ) as compared with trials without auditory stimulation . In contrast , older adults with minimal cognitive impairment ( Blessed test score , 5 - 10 ; n=8 ) showed an average reduction of 5.45cm/s in gait velocity ( F1.87,190.83=5.62 ; P=.005 ) and an average reduction of 3.88 steps/min in cadence ( F1.79,183.10=8.21 ; P=.001 ) under both auditory stimulation conditions . Neither baseline fall history nor performance of activities of daily living accounted for these differences . CONCLUSIONS Our results provide preliminary evidence of the differentiating effect of emotionally charged auditory stimuli on gait performance in older individuals with minimal cognitive impairment compared with those without minimal cognitive impairment . A divided attention task using emotionally charged auditory stimuli might be able to elicit compensatory improvement in gait performance in cognitively intact older individuals , but lead to decompensation in those with minimal cognitive impairment . Further investigation is needed to compare gait performance under this task to gait on other dual-task paradigms and to separately examine the effect of physiological aging versus cognitive impairment on gait during walking under auditory constraints AIM The aim of this study was to evaluate the interrater reliability and convergent validity of the American Academy for  Cerebral Palsy and Developmental Medicine  's ( AACPDM ) methodology for conducting systematic review s ( group design studies ) . METHOD Four clinicians independently rated 24 articles for the level of evidence and conduct using AACPDM methodology . Study conduct was also assessed using the Effective Public Health Practice Project scale . Raters were r and omly assigned to one of two pairs to resolve discrepancies . The level of agreement between individual raters and pairs was calculated using kappa ( α=0.05 ) and intraclass correlations ( ICCs ; α=0.05 ) . Spearman 's rank correlation coefficient was calculated to evaluate the relationship between raters ' categorization of quality categories using the two tools . RESULTS There was acceptable agreement between raters ( κ=0.77 ; p<0.001 ; ICC=0.90 ) and between assigned pairs ( κ=0.83 ; p<0.001 ; ICC=0.96 ) for the level of evidence ratings . There was acceptable agreement between pairs for four of the seven conduct questions ( κ=0.53 - 0.87 ) . ICCs ( all raters ) for conduct category ratings ( weak , moderate , and strong ) also indicated good agreement ( ICC=0.76 ) . Spearman 's rho indicated a significant positive correlation for the overall quality category comparisons of the two tools ( 0.52 ; p<0.001 ) . CONCLUSIONS The AACPDM rating system has acceptable interrater reliability . Evaluation of its study quality ratings demonstrated reasonable agreement when compared with a similar tool Parkinson 's disease ( PD ) and basal ganglia dysfunction impair movement timing , which leads to gait instability and falls . Parkinsonian gait consists of r and om , disconnected stride times — rather than the 1/f structure observed in healthy gait— and this r and omness of stride times ( low fractal scaling ) predicts falling . Walking with fixed-tempo Rhythmic Auditory Stimulation ( RAS ) can improve many aspects of gait timing ; however , it lowers fractal scaling ( away from healthy 1/f structure ) and requires attention . Here we show that interactive rhythmic auditory stimulation reestablishes healthy gait dynamics in PD patients . In the experiment , PD patients and healthy participants walked with a ) no auditory stimulation , b ) fixed-tempo RAS , and c ) interactive rhythmic auditory stimulation . The interactive system used foot sensors and nonlinear oscillators to track and mutually entrain with the human 's step timing . Patients consistently synchronized with the interactive system , their fractal scaling returned to levels of healthy participants , and their gait felt more stable to them . Patients and healthy participants rarely synchronized with fixed-tempo RAS , and when they did synchronize their fractal scaling declined from healthy 1/f levels . Five minutes after removing the interactive rhythmic stimulation , the PD patients ' gait retained high fractal scaling , suggesting that the interaction stabilized the internal rhythm generating system and reintegrated timing networks . The experiment demonstrates that complex interaction is important in the (re)emergence of 1/f structure in human behavior and that interactive rhythmic auditory stimulation is a promising therapeutic tool for improving gait of PD patients Patients with Parkinson 's disease ( PD ) walk with a shortened stride length and high stride-to-stride variability , a measure associated with fall risk . Rhythmic auditory stimulation ( RAS ) improves stride length but the effects on stride-to-stride variability , a marker of fall risk , are unknown . The effects of RAS on stride time variability , swing time variability and spatial-temporal measures were examined during 100-m walks with the RAS beat set to 100 and 110 % of each subject 's usual cadence in 29 patients with idiopathic PD and 26 healthy age-matched controls . Carryover effects were also evaluated . During usual walking , variability was significantly higher ( worse ) in the patients with PD compared with the controls ( P < 0.01 ) . For the patients with PD , RAS at 100 % improved gait speed , stride length and swing time ( P < 0.02 ) but did not significantly affect variability . With RAS at 110 % , reductions in variability were also observed ( P < 0.03 ) and these effects persisted 2 and 15 min later . In the control subjects , the positive effects of RAS were not observed . For example , RAS increased stride time variability at 100 and 110 % . These results demonstrate that RAS enables more automatic movement and reduces stride-to-stride variability in patients with PD . Further , these improvements are not simply a by-product of changes in speed or stride length . After walking with RAS , there also appears to be a carryover effect that supports the possibility of motor plasticity in the networks controlling rhythmicity in PD and the potential for using RAS as an intervention to improve mobility and reduce fall risk It is commonly agreed that a functional dissociation with respect to the internal vs external control of movements exists for several brain regions . This has , however , only been tested in relation to the timing and preparation of motor responses , but not to ongoing movement control . Using functional magnetic resonance imaging ( fMRI ) , the present study addressed the neuroanatomical substrate of the internal-external control hypothesis by comparing regional brain activation for cyclical bimanual movements performed in the presence or absence of augmented visual feedback .  Subjects performed a bimanual movement pattern , either with the help of on-line visual feedback of 
    Output:
    