Correlation of spasticity with hyperactive stretch reflexes and motor dysfunction in hemiplegia

Area of Science:

• Neurology
• Rehabilitation Medicine
• Motor Control

Background:

• Hemiplegia, often resulting from stroke, frequently leads to spasticity in the affected limb.
• Spasticity in the wrist-hand unit can significantly impair functional abilities.
• Understanding the relationship between spasticity and motor deficits is crucial for effective rehabilitation.

Purpose of the Study:

• To examine the correlation between spasticity and motor dysfunction in the wrist-hand unit of adult hemiplegic patients.
• To investigate the relationship between clinical spasticity and hyperactive stretch reflexes.

Main Methods:

• A sequential case series study involving 10 adult hemiplegic patients with varying degrees of wrist spasticity.
• Utilized Modified Ashworth Scale, grip strength, wrist range of motion, Fugl-Meyer test, and stretch reflex assessments (electromyographic and torque responses).

Main Results:

• Significant inverse correlations were observed between spasticity and grip strength, Fugl-Meyer scores, and Box and Blocks test scores (p = .001 to .005).
• A strong correlation was found between spasticity and electromyographic activity of stretch reflexes in active muscles (p = .005 and .007).
• No significant correlation was found between spasticity and the torque response of the stretch reflex.

Conclusions:

• Wrist spasticity is directly associated with diminished hand function in hemiplegic individuals.
• Hyperactive electromyographic response of the stretch reflex in active muscles serves as a reliable indicator of spasticity.