Does botulinum toxin injection site determine outcome in post-stroke plantarflexion spasticity? Comparison study of two injection sites in the gastrocnemius muscle: a randomized double-blind controlled trial.
OBJECTIVE
To determine if botulinum toxin type A injection at the proximal 2/10 and 3/10 of calf length, where the intramuscular nerve endings of the gastrocnemius muscle are densely distributed, is more efficacious in controlling plantarflexion spasticity than injection at distant sites within the same muscle.


METHODS
A double-blind randomized controlled trial.


METHODS
Two rehabilitation centres.


METHODS
Forty stroke patients were randomly allocated to two groups. Group A received injection at the proximal 2/10 and 3/10 of calf length, group B at and below the midbelly of the muscle. Both groups received 200 IU of botulinum toxin A and were followed up to eight weeks.


METHODS
Primary variables were the surface electromyography values recorded during plantarflexion; secondary variables were the Modified Ashworth Scale, Modified Tardieu Scale, clonus scale, 10-metre walking test, ABILOCO and Functional Ambulation Categories.


RESULTS
At baseline, the median Modified Ashworth Scale was 2.0 (range,1+ -3.0), and there were no significant differences between the two groups in all the parameters, including spasticity. Compared to baseline, no significant differences between the two groups were detected in all the surface electromyography and clinical parameters at week 8 (P > 0.05). Both groups showed significant improvement of spasticity with a median Modified Ashworth Scale of 1+ (range, 0.0-2.0) at eight weeks.


CONCLUSIONS
Botulinum toxin A injection was associated with a significant improvement from baseline to week 8 in both treatment groups, however, no significant difference between the 2 groups was observed, based on the electrophysiological and clinical parameters employed in this study.
Department of Rehabilitation Medicine, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon-si, Republic of Korea.
Sun
S
Im
Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Joo Hyun
JH
Park
Department of Rehabilitation Medicine, Bobath Memorial Hospital, Songnam-si, Republic of Korea.
Seong Kon
SK
Son
Department of Rehabilitation Medicine, Bobath Memorial Hospital, Songnam-si, Republic of Korea.
Jae-Eun
JE
Shin
Department of Rehabilitation Medicine, Yesung Hospital, Jaechon-si, Republic of Korea.
Sae Hoon
SH
Cho
Department of Rehabilitation Medicine, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon-si, Republic of Korea rootpmr@catholic.ac.kr.
Geun-Young
GY
Park
D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000627:therapeutic use; D004311:Double-Blind Method; D004576:Electromyography; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular / Q000379:methods; D008297:Male; D008875:Middle Aged; D009128:Muscle Spasticity / Q000188:drug therapy* / Q000209:etiology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000627:therapeutic use; D016059:Range of Motion, Articular; D020521:Stroke / Q000150:complications / Q000188:drug therapy*; D055815:Young Adult
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
Botulinum toxin; electromyography; injection location; muscle spasticity; randomized controlled trial; range of motion; stroke