Treatment outcome of local injection of botulinum toxin for claw toe: Differences between cerebral hemorrhage and infarction.

BACKGROUND: Some patients with post-stroke claw toe respond well to botulinum toxin (BoNT) treatment while others do not. This study was designed to assess the impact of stroke type (cerebral hemorrhage and cerebral infarction) on the outcome of BoNT treatment for claw toe. METHODS: We retrospectively examined the medical records of patients who received local BoNT (onabotulinumtoxin A) injections into the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) muscles. All patients suffered stroke-related leg paralysis and spasticity. RESULTS: The study participants were 58 patients (mean age, 61.4 ± 10.3 years, ± SD) with time since stroke of 6.7 ± 4.4 years. The stroke type was cerebral hemorrhage (n = 38) and cerebral infarction (n = 20). After a total of 124 BoNT administrations with medical records entries on the subjective symptoms, the odds for symptomatic improvement was approximately 5.8 times higher in patients of the infarction group compared with the hemorrhage group (OR = 5.787, 95% CI = 2.369-14.134, p = 0. 000). Fifty-one patients (32 with cerebral hemorrhage, 19 with cerebral infarction) received the first local BoNT injection and had available medical records, analysis of which showed a significantly higher rate of symptomatic improvement in patients of the infarction group than those of the hemorrhage group (p = 0.006). After adjustment by factors known to influence treatment outcome (degree of spasticity and paralysis, BoNT dosage, and extent of FDL muscle control of toe movements), the treatment effect was predominantly higher in patients with cerebral infarction. CONCLUSION: The BoNT treatment response was better for claw toes in cerebral infarction patients than in hemorrhage patients, possibly suggesting that claw toe is associated with more severe spasticity in this group of patients.

Effects of Flexor Digitorum Longus Muscle Anatomical Structure on the Response to Botulinum Toxin Treatment in Patients with Post-Stroke Claw Foot Deformity.

(1) Background: The purpose of this retrospective case-control study was to determine the relationship between the control of toe movements by flexor hallucis longus (FHL) and flexor digitorum longus (FDL) muscles and the response to treatment with botulinum toxin (BoNT) in post-stroke patients with claw toe. (2) Methods: Subjects with stroke-related leg paralysis/spasticity and claw toes received multiple injections of BoNT (onabotulinumtoxin A) into the FHL or FDL muscles. We investigated the relationship between the mode of transmission of FHL and FDL muscle tension to each toe (MCT) and treatment outcome using the data of 53 patients who received 124 injections with clinically recorded treatment outcome. We also dissected the potential variables that could determine the treatment outcome. (3) Results: The effectiveness of BoNT treatment was significantly altered by FDL-MCT (OR = 0.400, 95% CI = 0.162-0.987, p = 0.047). Analysis of the response to the first BoNT injection showed an odds ratio of FDL-MCT of approximately 6.0 times (OR = 0.168, 95% CI = 0.033-0.857, p = 0.032). The more tibial the influence of the FDL muscle on each toe, the better the treatment outcome on the claw toe. (4) Conclusions: The anatomic relation between FDL muscle and each toe seems to affect the response to treatment with BoNT in post-stroke patients with claw toes.

Claw Toe: Anatomic Guide for Injection of Botulinum Toxin into Foot Muscles.

BACKGROUND: Poor response to injection of botulinum toxin (BoNT) into the flexor digitorum longus (FDL) muscle has been reported especially in patients with claw foot deformity. We previously advocated BoNT injection into the flexor hallucis longus (FHL) muscle in such patients. Here, we determined the functional and anatomical relationships between FHL and FDL. METHODS: Toe flexion pattern was observed during electrical stimulation of FHL and FDL muscles in 31 post-stroke patients with claw-foot deformity treated with BoNT. The FHL and FDL tendon arrangement was also studied in five limbs of three cadavers. RESULTS: Electrical stimulation of the FHL muscle elicited big toe flexion in all 28 cases examined and second toe in 25, but the response was limited to the big toe in 3. FDL muscle stimulation in 29 patients elicited weak big toe flexion in 1 and flexion of four toes (2nd to 5th) in 16 patients. Cadaver studies showed division of the FHL tendon with branches fusing with the FDL tendon in all five limbs examined; none of the tendons was inserted only in the first toe. No branches of the FDL tendon merged with the FHL tendon. CONCLUSION: Our results showed coupling of FHL and FDL tendons in most subjects. Movements of the second and third toes are controlled by both the FDL and FHL muscles. The findings highlight the need for BoNT injection in both the FDL and FHL muscles for the treatment of claw-toe deformity.