Effect of botulinum toxin type-A in spasticity and functional outcome of upper limbs in cerebral palsy

Spasticity has been considered to be a main contributor to both the impairment of function as well as posture in children with cerebral palsy (CP). Patterns of upper limb motor involvement in CP vary with resultant limitations in daily independence, participation, and quality of life. Botulinum Toxin-A (BTX-A) is a potent neurotoxin which acts by preventing the release of acetylcholine (Ach) from presynaptic axon at motor end plate reducing focal spasticity. With literature established role of BTX-A available for lower limb spasticity in CP, the purpose of this study was to present an objective analysis of the effect of a single i.m. injection of BTX-A in reduction of spasticity in the upper limb as well as functional outcome in children (4-12yrs) with spastic CP.

A total of 28 patients (30 upper limbs) of spastic CP with minimum follow up of 6months were included in the study. Modified Ashworth Scale (MAS) and Modified Tardieu Scale (MTS) were used to measure the spasticity. Surface landmarks were used to give I.m. Botox in selected spastic muscles followed by targeted rehabilitation. Functional outcomes were measured by MACS (Manual Ability Classification System) and Canadian Occupational Performance Measure (COPM) before treatment, at 3 and 6 months follow up.

Pronator teres was the most frequently injected muscle followed by FCU and Adductor pollicis. MAS scores at all joints and MTS scores at forearm deteriorated between 3 and 6 months. However, MACS and COPM showed sustained improvement at 3months and 6months with statistically significant change.

I.m. BTX-A injected using anatomical landmarks had significant improvement in both clinical and functional outcome measures. We noticed significant improvement in MACS and COPM at 6 months despite return of local spasticity. It is safe and effective for spasticity of upper limbs in cerebral palsy and capable of improving function without major side effects. MACS & COPM are easy to use, less time consuming & easily adjusted to local needs. Randomized control trials with long follow up are required in future with special focus on dosing and timing, scoring system for functional outcome as per regional needs and issue for antibody formation for repeat injections of BTX-A.