Botulinum toxin in post-stroke patients: stiffness modifications and clinical implications

Area of Science:

• Neurology
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke often leads to upper limb spasticity, impacting motor function and quality of life.
• Botulinum toxin (BT) injections are used to manage muscle hypertonia, but objective quantification of its effects on stiffness is needed.

Purpose of the Study:

• To objectively quantify changes in upper limb stiffness and clinical function post-Botulinum toxin (BT) injection in chronic stroke patients.
• To evaluate the efficacy of BT in reducing spasticity, pain, and improving motor performance.

Main Methods:

• Eighteen chronic stroke patients with forearm flexor spasticity received BT injections.
• Spasticity assessed using the Ashworth scale; stiffness measured via passive stiffness index (ISI) and total stiffness index (TSI).
• Functional status evaluated with Barthel index, hand ability scale, and visual analogue scale (VAS) for pain; range of motion and strength also measured.

Main Results:

• Significant increases in isometric extension (IE) and extension range of motion (EROM) (p < 0.01, p < 0.05).
• Augmented stretch reflex threshold speed (SRTS) (p < 0.001) and decreased total stiffness index (TSI) (p < 0.001).
• Reduced Ashworth scores, improved hand function in 50% of patients, and pain relief in 17%.

Conclusions:

• Botulinum toxin (BT) is a valuable therapeutic option for managing post-stroke spasticity.
• BT offers immediate benefits including reduced muscle hypertonia, pain relief, and improved motor performance.
• Objective measures confirm BT's effectiveness in improving stiffness and function in stroke survivors.