The study aims to compare the effectiveness of BOTOX-A® (botulinun toxin A) placed between two different injection sites, namely at the proximal portion of the gastrocnemius(GCM) versus at the midbelly of the GCM.
Previous studies have used the midbelly of a muscle as the position where the motor endplates are most densely located. The reasoning behind this method was based on the previous works that showed most bands of cholinesterase activity to be located in specific topographical patterns at the center of the muscle fiber. These results have been used as landmarks to place the injections. Current standard guidelines recommend that botulinum toxin be placed at the 4 quadrants of the midbelly portion of the gastrocnemius (GCM) muscle. However, recent cadaveric research studies on the distribution of the intramuscular endings of the GCM suggest that the highest branch density is found within the upper 20-30% length of the calf. Therefore, in accordance to the theory that effect of botulinum toxin are greatest at sites where the intramuscular endings are most dense, the location where these toxins should be placed would be at these proximal sites of the GCM rather than at the midbelly.
40 recruited patients will be allocated into either the intramuscular ending targeted (ie.upper portion of calf) or midbelly targeted group.
Each subject will undergo a total number of 4 assessments; prior to the injection and 2,4and 8 weeks post injection.
- BOTOX-A® Drug
Other Names: Generic Name: Botulinum toxin type A Intervention Desc: 200 units, single treatment only ARM 1: Kind: Experimental Label: Intramuscular ending Targeting Description: Botox 200 units placed at the upper 1/10 and 2/10 length of the GCM ARM 2: Kind: Experimental Label: Midbelly Targeting Description: A total of 200 units will be placed at the four quadrants of the midbelly portion of the GCM.
- Allocation: Randomized
- Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
- Purpose: Treatment
- Endpoint: Efficacy Study
- Intervention: Parallel Assignment
|Type||Measure||Time Frame||Safety Issue|
|Primary||Change from baseline for EMG (electromyogram) activity||week 8||No|
|Secondary||Change from baseline of GCM tone a measured on the Modified Ashworth Scale (MAS)||Change from baseline at 8 weeks||No|
|Secondary||Change from baseline of Ankle Range of motion||Change from baseline at 8 weeks||No|
|Secondary||Change from baseline of gait speed with 10 meters walk test||Change from baseline at 8 weeks||No|
|Secondary||Change from baseline of ABILOCO scale||Change from baseline at 8 weeks||No|
|Secondary||Change from baseline of Disability Assessment Scale||Change from baseline at 8 weeks||No|
|Secondary||Change from baseline of Functional Ambulation Category Scale||Change from baseline at 8 weeks||No|
|Secondary||Change of baseline of Lindmark Modified Fugyl Meyer Scale||Change from baseline at 8 weeks||No|
|Secondary||Change from baseline of Tardieu angle of ankle||Change from baseline at 8 weeks||No|