Novel Uses for Botulinum Neurotoxin in Upper Limb Surgery

Abstract

To the Editor: Recent years have seen Botulinum Neurotoxin (BoNT) injections emerge as a treatment option in the management of muscle spasticity. Spasticity is observed in many upper motor neuron problems but stroke and cerebral palsy are two of the more common conditions for which BoNT has been used to reduce muscle spasticity, release contractures and improve function [1]. Spasticity in the hand and forearm can be particularly problematic due to the prominent role of the upper extremity in activities of daily living [2]. BoNT exerts its effect at the neuromuscular junction to block acetylcholine release into the synaptic cleft and cause muscle relaxation [3]. Its use is limited by the ability of axons to regenerate at the neuromuscular junction; hence the effects of toxin injections are only temporary. There are also limitations in cases of prolonged muscular contracture which result in postural abnormalities and commonly require corrective surgery. Toxin use is often used as an alternative to tendon lengthening or tendon transfer; however our centre is now implementing a number of novel uses for BoNT injections with a view to improving outcomes in our cerebral palsy patients. We report a 16 year old patient with cerebral palsy who underwent a left flexor carpi radialis (FCR) to extensor carpi radialis longus (ECRL) tendon transfer with release of flexor digitorum superficialis (FDS) and flexor pollicis longus (FPL). Ultrasound guided BoNT injections were administered 2 weeks preoperatively to FCR, FDS, FDP, and FPL. The 2 week delay allowed the BoNT to exert its full effect and achieve a maximum preoperative reduction in muscle tension. We typically use doses of 50 units BoNT per muscle. Our main finding is that BoNT injections can be valuable when used in conjunction with tendon lengthening and tendon transfer techniques, as a combination of surgery and injections produce a synergistic effect. With regards to tendon lengthening in FDS and FPL, preoperative reduction in muscle tension made achievement of optimum tendon length and hand position a more straightforward process. Reduced muscle tension makes the surgeon's task easier and leads to a better postoperative result. This finding supports results in animal models where manipulation of the muscle-tendon unit was made easier by preoperative injection of BoNT [4]. The benefits of this technique are also seen in tendon transfer. Firstly, reducing tension in the transferred FCR tendon allows for an easier transfer, attachment and attainment of an optimum hand position. Secondly, by reducing tension on antagonistic muscles (wrist flexors FDS and FDP), the ability to achieve an optimum hand position is more straightforward and, theoretically, the risk of post operative failure is reduced as the antagonistic force across the transferred tension is less. At present, this technique has been used on a number of patients at our centre and so far the results are promising with the surgeon noting the ease with which a good hand position is achieved intraoperatively co...

Botox and Thumb MCP Radial Collateral Ligament Reconstruction

“…8,9,14 Nevertheless, some concerns remain including the potential for local weakness, lack of standardization of biological activity in different preparations, variations in injection methods, and cost-effec-tiveness 13 (BoNT-A has been used in children for spasticity in the hand, in the fingers for flexor tendon repair, after extensor tendon repair, and for Raynaud's phenomenon). 9,15 It is reversible, temporary, and paralytic when injected into muscle, leading to peak effects by 2 weeks, clinically detectable weakness over the next 2 to 4 months, and nearly full return of muscle mass, electrophysiologic variables, and muscle force generation by 6 months. 8,9 In 2007, Ma and colleagues 8 described a form of "bioprotection" for an Achilles tendon repair in Sprague Dawley rats by injecting BoNT-A into the gastrocnemius muscle.…”

Effects of low-level laser therapy (LLLT 808 nm) on lower limb spastic muscle activity in chronic stroke patients

“…Fig. 1 Flowchart of the muscle tissue alterations caused by spasticity and the LLLT effects in the muscle tissue [24][25][26][27][28][29][30][31][32][33][34] Exclusion criteria Presence of hypoesthesia and/or hyperesthesia of the involved lower limb to be studied; presence of active infection and rash at the site of application of the electrodes to be used for electromyography; joint stiffness, contractures, and deformities; Wernicke and Broca's aphasia; uncontrolled hypertension; presence of neoplastic lesions at the site of application; intake of analgesics and/or anti-inflammatory medications during the 2-week evaluation; stroke patients who were on medication containing steroids or steroid medications; and Fitzpatrick Skin Scale type IV and type V. Normally in a clinic situation, patients with darker-pigmented skin can receive the LLLT treatments, but the laser may need to be moved around on the skin, more frequently due to uncomfortable heating [35]. We wanted to keep the laser application method as consistent as possible across all patients; therefore, those patients with darker-pigmented skin were excluded from this research study.…”