Non-reflex mediated changes in plantarflexor muscles early after stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke often leads to spasticity, affecting motor function and mobility.
• Understanding the progression of non-reflex spasticity post-stroke is crucial for effective rehabilitation.
• Early detection of spasticity can inform preventative strategies.

Purpose of the Study:

• To investigate the development of non-reflex spasticity in plantarflexor muscles at 2 and 4 months after stroke.
• To examine the relationship between these spasticity changes and the level of motor impairment.
• To assess the potential of early myometry testing for identifying at-risk patients.

Main Methods:

• A longitudinal study involving adults with hemiparesis (HP) and a control group (CTLs).
• Resistive torque (RT) of plantarflexors was measured using myometry during passive dorsiflexion.
• Secondary measures included the Ashworth score, ankle range of motion (ROM), and Fugl-Meyer motor subscore.

Main Results:

• Significantly higher RT values were observed in the affected limb at 2 months (39%) and 4 months (43%) post-stroke compared to the unaffected limb.
• No significant increase in RT was found between 2 and 4 months post-stroke.
• RT changes showed a strong correlation with each other but weak, non-significant correlations with Ashworth score, ROM, and Fugl-Meyer scores.

Conclusions:

• Non-reflex spasticity changes are detectable as early as 2 months post-stroke.
• These changes do not significantly progress between 2 and 4 months post-stroke.
• Myometry at 2 months can identify individuals at risk of developing severe passive muscle stiffness, independent of overall impairment level.