Onabotulinumtoxin A (trade name Botox) received FDA approval for treatment of chronic migraines on October 15, 2010. The toxin is injected into the head and neck to treat these chronic headaches. Approval followed evidence presented to the agency from two studies funded by Allergan showing a very slight improvement in incidence of chronic migraines for migraine sufferers undergoing the Botox treatment.[86][87]
The cosmetic benefits came to light in the 1990s by happy coincidence. “The aesthetic indications were purely happenstance,” says board-certified surgeon and clinical professor Seth L. Matarasso, MD, who has been treating his clients with Botox since the 1990s but is not affiliated with the brand. “Dr. [Jean] Carruthers was working with patients with strabismus...[and] with diplopia [double vision], and her patients were coming in and saying, ‘Gee, my wrinkles are better.'" Soon enough, doctors were using Botox for what it is most commonly associated with today — nixing lines.
In many children, there are a few muscle groups that can have very active spasticity. A more focal approach to these muscles would be better than a widespread approach. In this case a doctor may advise a nerve block to interrupt the signal to the muscle that is spastic. Once the signal that is carried to the muscle by the nerve is interrupted, the spasticity will decrease.

Once the protein stops functioning at the neuromuscular junction, it is broken down into its harmless components (amino acids) and either recycled for use in other proteins or excreted by the kidneys. "The bigger the muscle, the quicker you'll see motion return," says Rowe. "Likewise, the smaller the muscle, the longer the effect of botox lasts." It doesn't have a tolerance effect, either—your body never gets used to Botox.
The seven toxin types (A-G) have different tertiary structures and sequence differences.[35][36] While the different toxin types all target members of the SNARE family, different toxin types target different SNARE family members.[34] The A, B, and E serotypes cause human botulism, with the activities of types A and B enduring longest in vivo (from several weeks to months).[35]
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The needle should be inserted approximately 2 mm into the detrusor, and 30 injections of 1 mL (~6.7 Units) each (total volume of 30 mL) should be spaced approximately 1 cm apart (see Figure 1). For the final injection, approximately 1 mL of sterile normal s aline should be injected so that the remaining BOTOX in the needle is delivered to the bladder. After the injections are given, the saline used for bladder wall visualization should be drained. The patient should be observed for at least 30 minutes post -injection.
If going back for additional treatments three or four times a year sounds like a lot of treatments, the good news is that the more Botox treatments you get, the fewer Botox units you'll need. With each repeat Botox session, the frontalis muscle and other facial muscles surrounding Botox injection sites get a little weaker and become "trained" to not contract.
When pregnant rats received single intramuscular injections (1, 4, or 16 Units/kg) at three different periods of development (prior to implantation, implantation, or organogenesis), no adverse effects on fetal develop ment were observed. The developmental no-effect level for a single maternal dose in rats (16 Units/kg) is approximately 2 times the human dose of 400 Units, based on Units/k g.
Strabismus is caused by imbalances in the actions of muscles that rotate the eyes, and can sometimes be relieved by weakening a muscle that pulls too strongly, or pulls against one that has been weakened by disease or trauma. Muscles weakened by toxin injection recover from paralysis after several months, so it might seem that injection would then need to be repeated. However, muscles adapt to the lengths at which they are chronically held,[18] so that if a paralyzed muscle is stretched by its antagonist, it grows longer, while the antagonist shortens, yielding a permanent effect. If there is good binocular vision, the brain mechanism of motor fusion, which aligns the eyes on a target visible to both, can stabilize the corrected alignment.
The incidence of UTI increased in patients who experienced a maximum post-void residual (PVR) urine volume ≥200 mL following BOTOX injection compared to those with a maximum PVR <200 mL following BOTOX injection, 44% versus 23%, respectively. No change was observed in the overall safety profile with repeat dosing during an open-label, uncontrolled extension trial.

Botox is injected in and around the head on an average of every three months. It blocks signals from nerves and paralyzes the muscles, ultimately preventing migraines. It is known to relax the muscles that usually contract during migraines. It’s also the only FDA-approved medication to prevent migraines before they even start! It’s known to prevent about nine migraines per month.

Botulinum toxin is used to treat a number of disorders characterized by overactive muscle movement, including post-stroke spasticity, post-spinal cord injury spasticity, spasms of the head and neck,[8] eyelid,[9] vagina,[10] limbs, jaw, and vocal cords.[11] Similarly, botulinum toxin is used to relax clenching of muscles, including those of the oesophagus,[12] jaw,[13] lower urinary tract and bladder,[14] or clenching of the anus which can exacerbate anal fissure.[15] It may also be used for improper eye alignment.[16] Botulinum toxin appears to be effective for refractory overactive bladder.[17]
The one side effect that we most commonly see with Botox for migraine, ironically, is increased headache pain in the days immediately following the injections. Interestingly, some patients have the opposite effect, noticing immediate pain relief. That may be due to an acupuncture-like response, where poking needles into unhappy muscles actually makes them feel better.

When moving a spastic limb through its range of motion, one feels a resistance to movement that increases with the speed at which one moves the limb. This is the definition of spasticity, but other terms such as increased muscle tone, hypertonicity, spastic dystonia, or flexor / extensor spasms are used to describe this resistance. In clinic the term "muscle spasticity" will be used to reduce confusion of terms.
"A migraines is an inherited neurological condition that features headaches as the most common symptom," says Robbins. "Headaches are not the only symptoms people can have. They can have sensitivity to the environment around them like light and sound. They can have nausea, which can lead to vomiting. They can have blurred vision. In a minority, but sizable number of people, it can progress to what we call chronic migraines."
In clinical trials, 30.6% of patients (33/108) who were not using clean intermittent catheterization (CIC) prior to injection, required catheterization for urinary retention following treatment with BOTOX® 200 Units as compared to 6.7% of patients (7/104) treated with placebo. The median duration of post-injection catheterization for these patients treated with BOTOX® 200 Units (n = 33) was 289 days (minimum 1 day to maximum 530 days) as compared to a median duration of 358 days (minimum 2 days to maximum 379 days) for patients receiving placebo (n = 7).