Partial Blocks of Rectus Femoris and Soleus With Botulinum Toxin Type A (Xeomin®) to Improve Gait in Hemiparesis

The most common motor deficiency after stroke or traumatic brain injury is hemiparesis. Most hemiparetic patients recover walking, but rarely with a speed permitting easy ambulation outdoors with family or friends. One of the mechanisms of gait impairment in hemiparesis is insufficient active hip flexion during swing phase, which leads to insufficient ground clearing at swing phase, with associated gait slowness and risks of fall.

The main hypothesis behind the present study is that insufficient hip flexion during hemiparetic gait is partly due to overactivity of rectus femoris. Focal treatment of lower limb muscle overactivity using botulinum toxin has not been demonstrated to increase walking speed in hemiparesis as yet. However, most studies have focused distally, on improving foot dorsiflexion only. The purpose of this study is to compare the effects of botulinum toxin injection and placebo in rectus femoris (RF) + plantar flexors versus plantar flexors only.

Randomized, double blind, parallel-group study in chronic, non-evolutive brain damaged patients (\>6 months since stroke or brain trauma) and ambulating at \<1.3 m/sec at maximal speed barefoot (AT10) Group 1: 150U (x 7.5 ml) placebo Sol + 150U (x 7.5 ml) placebo RF + 100U (5ml) placebo distributed between tibialis posterior, FHL (flexor hallucis longus), FCB (flexor digitorum brevis), gastrocnemius muscles or peroneus longus, based upon investigator clinical judgment.

Group 2: 150U (x 7.5 ml) Xeomin® 20U/ml Sol + 150U (x 7.5 ml) placebo RF + 100U (5ml) Xeomin® distributed between tibialis posterior, FHL (flexor hallucis longus), FCB (flexor digitorum brevis), gastrocnemius muscles or peroneus longus, based upon investigator clinical judgment.

Group 3: 150U (x 7.5 ml) Xeomin® 20U/ml Sol + 150U (x 7.5 ml) Xeomin® 20U/ml RF + 100U (5ml) Xeomin® distributed between tibialis posterior, FHL (flexor hallucis longus), FCB (flexor digitorum brevis), gastrocnemius muscles or peroneus longus, based upon investigator clinical judgment.

Eligibility Criteria:
Inclusion Criteria

* Hemiparesis from stroke, brain trauma, or non evolutive brain tumor \>6 months before enrolment
* Hip flexion at swing phase on the paretic side clinically insufficient (rated \<15° by the clinical investigator)
* Passive ankle dorsiflexion clinically insufficient at late stance (rated \<90° by the clinical investigator)
* Maximal ambulation speed barefoot over 10 metres \< 1,3 m/sec
* Age ≥ 18
* Signed consent form

Exclusion Criteria

* Ambulation impossible barefoot
* Passive hip flexion amplitude (with the knee flexed) \< 45° on paretic side
* Severe intercurrent disease ou cognitive dysfunction making effective communication or study participation impossible.
* Current anticoagulation with INR\> 3,5 ; less than 15 days prior to D1
* Pregnancy, lactation, or premenopause woman not taking contraception
* Hypersensitivity to botulinum toxin or its excipients, myasthenia gravis, Lambert-Eaton syndrome, concomitant aminoside treatment.
* Infection or inflammation at injection sites.
* Injection in lower limb less than 3 months prior to D1
* Person not covered by social security