Botulinum toxin type-A in the management of spastic equinovarus deformity after stroke: Comparison of 2 injection techniques

Objective:

To retrospectively compare 2 injection techniques in the management of spastic equinovarus deformity after stroke.

Methods:

Patients with stroke were seen at King Hussein Medical Center, Amman, Jordan between January and December 2009. The study design involved an open label retrospective analysis of medical records of 2 groups of comparable age and onset of first stroke. Botulinum toxin was injected into the calf muscles at 2 sites in group I (12 patients) and 4 sites in group II (14 patients). Functional gain was evaluated by the time to walk 10 meters at month one, 3, and 6 compared with baseline.

Results:

There was significant improvement in walking time in each study group. However, there was no significant difference between the 2 groups as measured by the 10-meter walking time.

Conclusion:

Fewer injection sites would minimize patient discomfort and possibly the production of antibodies, yielding similar therapeutic effects.Stroke is the second leading cause of death and disability globally, according to the World Health Organization.1 More than one third of stroke survivors never regain adequate limb function.2 A contributing impediment to regaining function is spasticity. Defined as a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, spasticity results from hyper-excitability of the stretch reflex, one component of upper motor neuron syndrome.3 This may affect limb position and activities of daily living.4 Spasticity contributes to disability in post-stroke patients with a frequency of 41.6%.5 Botulinum toxin is a neurotoxin that acts on the neuromuscular junction at the presynaptic site. It inhibits the release of acetylcholine, thus leading to muscle weakness and reduced muscle tone.6 The use of botulinum toxin type-A (BTX-A)7,8 in the management of spastic equinovarus deformity after stroke has been shown to be effective in reducing muscle tone, reducing pain, improving gait, and facilitating other rehabilitation programs.9,10 Side effects of botulinum toxin include local skin reaction and the spread of weakness to the adjacent non-injected muscles. Contraindications to botulinum toxin include pregnancy, lactation, neuromuscular junction disorders, and concurrent use of aminoglycosides.11 However, so far there has been no agreement on the number of injection sites for the best delivery of the toxin to produce the maximum therapeutic effects.12,13 The objective of the current study was to compare the clinical efficacy of injecting BTX-A (Dysport^®) into 2 sites (the lateral and medial heads of gastrocnemius) with a 4-site technique (gastrocnemius and soleus) in the management of post-stroke lower limb spasticity.