Characterizing upper extremity motor behavior in the first week after stroke.

Jessica Barth,Peter S Lum,Dorothy F Edwards,Abigail Mitchell,Alexander W Dromerick,Shashwati Geed,François Tremblay

doi:10.1371/journal.pone.0221668

Abstract

BackgroundAnimal models of brain recovery identify the first days after lesioning as a time of great flux in sensorimotor function and physiology. After rodent motor system lesioning, daily skill training in the less affected forelimb reduces skill acquisition in the more affected forelimb. We asked whether spontaneous human motor behaviors of the less affected upper extremity (UE) early after stroke resemble the animal training model, with the potential to suppress clinical recovery.MethodsThis prospective observational study used a convenience sample of patients (n = 25, mean 4.5 ±1.8) days after stroke with a wide severity range; Controls were hospitalized for non-neurological conditions (n = 12). Outcome measures were Accelerometry, Upper-Extremity Fugl-Meyer (UEFM), Action Research Arm Test (ARAT), Shoulder Abduction/ Finger Extension Test (SAFE), NIH Stroke Scale (NIHSS).ResultsAccelerometry indicated total paretic UE movement was reduced compared to controls, primarily due to a 44% reduction of bilateral UE use. Unilateral paretic movement was unchanged. Thus, movement shifted early after stroke; bilateral use was reduced and unilateral use of the non-paretic UE was increased by 77%. Low correlations between movement time and motor performance prompted an exploratory factor analysis (EFA) revealing a 2-component solution; motor performance tests load on one component (motor performance) whereas accelerometry-derived variables load on a second orthogonal component (quantity of movement).ConclusionsEarly after stroke, spontaneous overall UE movement is reduced, and movement shifts to unilateral use of the non-paretic UE. Two mechanisms that could influence motor recovery may already be in place 4.5 ± 1.8 days post stroke: (1) the overuse of the less affected UE, which could set the stage for learned non-use and (2) skill acquisition in the non-paretic limb that could impede recovery. Accurate UE motor assessment requires two independent constructs: motor performance and quantity of movement. These findings provide opportunities and measurement methods for studies to develop new behaviorally-based stroke recovery treatments that begin early after onset.

Highlights

Of the estimated 7 million stroke survivors in the United States, up to 88% are thought to have upper extremity (UE) motor involvement [1,2,3]
Low correlations between movement time and motor performance prompted an exploratory factor analysis (EFA) revealing a 2component solution; motor performance tests load on one component whereas accelerometry-derived variables load on a second orthogonal component
Two mechanisms that could influence motor recovery may already be in place 4.5 ± 1.8 days post stroke: (1) the overuse of the less affected UE, which could set the stage for learned non-use and (2) skill acquisition in the non-paretic limb that could impede recovery

Summary

Introduction

Of the estimated 7 million stroke survivors in the United States, up to 88% are thought to have upper extremity (UE) motor involvement [1,2,3]. Several motor behavioral factors (timing of motor training, dosing, and use of non-paretic forelimb) and various medications meaningfully influence rodent forelimb motor recovery [7,8,9] These factors seem relevant to conventional human rehabilitation in clinical settings, with the potential to influence final motor outcomes in patients. We asked whether spontaneous human motor behaviors of the less affected upper extremity (UE) early after stroke resemble the animal training model, with the potential to suppress clinical recovery

Results

Discussion

Conclusion