Botulinum toxin principle The presynaptic membrane of the nerve endplates blocks the release of acetylcholine into the synaptic gap; the nerve endplates gradually degenerate and die, resulting in the inability of the affected nerve to stimulate the contraction of the innervated muscle, causing a temporary reduction in muscle strength or paralysis. The effective action of botulinum toxin usually arrives within 3-14 days, and the blocking effect can last for several 3-4 months. When the motor nerve endings produce new shoots and form new motor end plates and replace the dead end plates, the muscle regains innervation and gradually regains function or reappears in a state of muscle spasm. Is botulinum toxin safe? Botulinum toxin type A is a toxin that was first discovered when people accidentally ate spoiled sausage and died from ingesting large amounts of botulinum toxin. The current projected use limit for botulinum toxin type A is an LD50 of approximately 40 units/kg, or 2,400 units for a 60 kg person. However, the amount currently used in clinical applications is very small and therefore safe. Botulinum toxin type A treatment is safe and no teratogenicity has been reported, but after all, experience is limited and therefore, it is not recommended for pregnant or breastfeeding women. Botox should not be used in patients with neuromuscular diseases, especially those affecting the neuromuscular junction, such as myasthenia gravis. In contrast, allergies and hypersensitivity to the drug, infections or skin breaks in the injection area, patients with fever and acute infectious diseases, and patients with serious organ diseases should be contraindicated for Botulinum toxin injections. Because aminoglycoside antibiotics (such as gentamicin) can enhance the effect of botulinum toxin, the use of these antibiotics should be prohibited during the use of botulinum toxin. In addition, cholinesterase antagonists, succinylcholine, arrow toxin-like depolarization antagonists, sulfatase, quinidine, calcium channel blockers, lincomycin, polymyxin, etc. are prohibited during botulinum toxin. Nevertheless, Botox treatment may have certain complications and side effects, often occurring 3 to 5 days after treatment, but of course these side effects will all lessen with time until they disappear, usually gradually fading in 2 to 4 weeks. The common ones are skin allergy and rash, numbness and pain at the injection site, bleeding and hematoma at the injection site, “flu-like” symptoms, weakness of adjacent muscles, high dose and repeated injections may cause immune complex disease, muscle paralysis resulting in inability to make various expressions and false mask-like sensation, and anaphylaxis may occur in very few patients. Shock. Botulinum toxin injections generally have no effect at the time of injection, and it takes 3 d to 2 weeks for the drug to take effect, so it is not possible to judge prematurely whether the treatment dose is insufficient. Since repeated injections can cause immune resistance, additional injections within 3 months after injection are not advisable to avoid the effect of repeated injections. It is generally believed that the injection can be repeated after 3 months when the therapeutic effect is weakened, and at this time, the repeated injection can still be efficacious in general, and the accumulation of poisoning will not occur by repeated injection. After injection, local ice should be applied; local pressure should be applied gently after injection instead of massage, and local massage should not be applied within 2-3 hours after injection; active muscle contraction activity and electrical stimulation after injection are conducive to internalization of drugs and improvement of drug action. Therefore, patients should be encouraged to strengthen functional exercises after injection without resting and braking. Evidence from 20 and 2 meta-analyses illustrates that treatment with botulinum toxin results in a significant decrease in muscle tone and improvement in passive function (reduced impairment and increased ability to participate in activities). There is growing evidence that reducing spasticity improves active function, i.e., reduces activity limitation. To date, although there are no randomized clinical trials, functional improvement has been reported by reducing knee stiffness gait. Reducing muscle tone increases the likelihood of functional training. Therefore, the use of botulinum toxin is beneficial in improving function, and repeated use of botulinum toxin can significantly improve mobility, improve the ability to use the affected limb, reduce the burden on caregivers, and is an effective method of relieving muscle spasm.