M.TAY1, J.M.KIM1, S.L.THAM1, D.K.RAJESWARAN1, W.L.LUI1, K.H.KONG1
Tan Tock Seng Hospital1
Muscle weakness is a frequent sequelae of stroke, resulting in functional impairment. However, our understanding of the effect of stroke on muscle is not well understood, as structural muscle changes in the early poststroke period have not been well described. Our objective is to investigate early ultrasound-derived muscle architecture in the hemiplegic upper and lower limbs in patients with stroke.
This is a prospective observational study, which recruited 40 adult patients who had experienced a first ever unilateral stroke (ischemic or hemorrhagic) with a duration of <1 month post stroke, and had hemiplegic weakness in both upper and lower limbs. Ultrasound evaluation was used to assess the brachialis, vastus lateralis and medial gastrocnemius on both the hemiplegic and normal side in terms of pennation angle, fascicle length, muscle thickness and echo intensity. Clinical variables including the Motricity Index, Modified Ashworth Scale (MAS) and Functional Independence Measure (FIM)-walk were recorded.
We found reduced mean muscle thickness (p<0.001) and increased echo intensity (p<0.001) in the brachialis muscle, increased echo intensity (p=0.002) in the vastus lateralis muscle, and reduced muscle thickness (p<0.001) with increased echo intensity (p<0.001) in the medial gastrocnemius muscle compared to the normal side. There were no significant correlations between ultrasound findings and Motricity Index, MAS or FIM-walk scores.
Changes in ultrasound-derived muscle measurements in the hemiplegic limbs occur in patients with subacute stroke. These findings may help shed light on the optimal timing and intensity of rehabilitation protocols for stroke patients to preserve muscle structural integrity and regain function.