Botox

It was in 1950 that Dr. Vernon Brooks first proposed the medical use of botulinum toxin (Botox) to reduce states of muscle hypercontractility, but it was not until 1980 that the ophthalmologist Alan Scott uses this toxin in humans for the treatment of strabismus.4,5 In 1989, the use of botulinum toxin type A was definitively accepted by the FDA for the treatment of blepharospasm, strabismus and spasm. the hemiface. The product is marketed under the name Botox in the same year. In 1991, another preparation of botulinum toxin type A was approved in England and marketed under the name Dysport. These two products are equivalent in their indications, but the number of botulinum toxin units per vial is not the same (one vial of Botox is equivalent to 100 U, one vial of Dysport is equivalent to 500 U). Due to the composition of the injectable product, the packaging is not the same. Botox can be stored in the freezer at a temperature of around ¬5 ° C, while Dysport can be stored at 2-8 ° C. These products are in the form of crystals which must be diluted in physiological solution (1-10 ml / 100 U according to the indications and according to the authors). The amount of diluted toxin depends essentially on the indications, for example, the dose used in the treatment of spasticity is about ten times greater than that used in aesthetic medicine, with a greater risk of immunological resistance (cf. . side effects).

The nerve impulse causes the release of acetylcholine at the neuromuscular junction which will cause muscle contraction.

Botulinum toxin by inhibiting the release of acetylcholine in the synaptic cleft, prevents muscle contraction. Affected muscle junctions are inhibited. The muscle fiber behaves as if there is denervation.

Before the resumption of synaptic functioning (synthesis of new molecules), a phenomenon of synaptic remodeling occurs. In fact, from the first days following the injection of botulinum toxin, there is a budding of new nerve endings starting from the terminal axon which thus re-establishes contact with the muscle as is the case in the muscles re-innervated after lesion of the axon. This process explains the reversible effect of an injection of botulinum toxin. Usually, muscle function returns to normal over time after four to five months.

Since the first therapeutic application in 1980 in strabismus, botulinum toxin has been used in the symptomatic treatment of numerous pathologies characterized by hyperactivity of certain muscle groups or dysregulation of the autonomic nervous system.

It is commonly used to treat patients with focal dystonias (spasmodic torticollis, blepharospasm, writer's cramp, musician's cramp, other limb dystonias, spasmodic dysphonias, oromandibular dystonias, head tremor, recurrent mandible dislocation. ), hemifacial and postparalytic spasm. Its use also helps reduce spasticity (cerebral palsy, stroke, multiple sclerosis).

Its indication is also established in various indications such as vesicosphincter dyssynergies, achalasia, spasms of the sphincter of Ody, anal fissures, localized hyperhidrosis, crocodile tears and other indications, such as fibromyalgia. or tension headaches.

The injection of botulinum toxin into the sites of hyperhidrosis significantly improved the quality of life of these patients. In 1996, Bushara et al. were the first to suggest the possible indication of botulinum toxin in the treatment of hyperhidrosis. They noted that patients treated for spastic torticollis had a decrease in sweat in the treated area.

Botulinum toxin decreases sweating by inhibiting the contraction of the myoepithelial cells responsible for emptying the sweat glands. These cells are controlled by the sympathetic cholinergic mediated system.

Treatment with botulinum toxin is indicated in excess sweating of functional origin.

The most publicized use currently concerns the treatment of expression lines on the upper part of the face. In fact, the frontal muscle, the procerus muscle, the corrugator muscle and the orbicularis muscle are skin muscles (muscle stuck to the skin). When the muscle contracts, the skin on it follows it and a wrinkle appears. It is enough to block the muscles for the wrinkles to disappear. The first results appear 48 hours after the injection and are complete after ten days. The contraction resumes gradually from the 4th month.

Adverse effects vary according to the indications. In the case of strabismus, the paralysis caused by one or more extraocular muscles can lead to spatial disorientation, double vision, ptosis. When used for blepharospasm, the toxin can cause ptosis, irritation, and tearing due to dry eye or photophobia. For cervical dystonia, the most serious side effect is swallowing disorder.

Palpebral ptosis (ptosis) is the most important and most common side effect for treating wrinkles. It is noted in the event of damage to the levator muscle of the upper eyelid by the diffusion of botulinum toxin.

Administration of botulinum toxin is contraindicated in the presence of injection site disease, peripheral neurological disease, or neuromuscular junction disorder such as myasthenia gravis. The use of the toxin is also contraindicated in pregnant women.

Botulinum toxin, better known under the name of Botox, helps to treat expression lines (frown lines, crow's feet, horizontal lines on the forehead), as well as problems with excessive sweating. It can be combined with other rejuvenation methods such as peels, lasers or fillers.

Expression lines are the first to appear on the face. They arise from the movements of our face when we express our emotions.

• - The horizontal lines of the forehead stand out when we open our eyes wide in surprise.
• - The frown line between the two eyebrows appears when one frowns to think.
• - Crow's feet form at the corners of the eyes when we smile or laugh.
• - Fine vertical wrinkles line the lips, the mouth being a particularly mobile region.

In young people, the skin regains its smooth appearance after each muscle contraction. But from your thirties onwards, the skin becomes less elastic and it eventually keeps the mark of small furrows when it is deformed. These furrows will then gradually widen and remain permanently visible.