Upper Limb Motor Function Affects the Outcome after Treatment with Botulinum Toxin A

Area of Science:

• Neurology
• Rehabilitation Medicine
• Pharmacology

Background:

• Botulinum toxin A (BoNT-A) is a recognized treatment for reducing upper limb spasticity.
• Understanding how pre-existing motor function influences BoNT-A treatment outcomes is crucial for optimizing patient care.

Purpose of the Study:

• To investigate the differential effects of BoNT-A on upper limb motor function based on patients' baseline motor capabilities.
• To identify specific functional improvements and limitations associated with BoNT-A treatment in relation to initial Fugl-Meyer Assessment scores.

Main Methods:

• Sixty-one patients with upper limb spasticity received BoNT-A treatment.
• Limb function was assessed using the Fugl-Meyer Assessment upper extremity (FMA-UE), modified Ashworth scale, passive range of motion, and disability assessment scale.
• Patients were stratified into higher and lower FMA-UE score groups based on pre-treatment evaluations.

Main Results:

• Both patient groups showed significant improvements in FMA-UE total and modified Ashworth scale scores post-treatment.
• The higher FMA-UE score group demonstrated significant improvement in FMA-UE subscale A but a decrease in subscale C, while the lower FMA-UE score group improved significantly in total FMA-UE, subscales A, and B.
• Functional gains in activities like dressing and hygiene were observed, with specific improvements varying between the groups and over time.

Conclusions:

• The therapeutic response to BoNT-A for upper limb spasticity is influenced by the patient's baseline motor function.
• Clinical decision-making for BoNT-A administration, particularly in finger flexor muscles, should involve a nuanced assessment of individual motor function to tailor treatment effectively.