Botulinum Toxins
Botulinum toxin injection therapy, an injection of the neurotoxin, clostridium botulinum, is used to treat dystonia “ a neuromuscular disorder that produces involuntary muscle contractions, or spasms “ in the eyes, neck, face, voice box or the smooth muscle in the bladder. The goal of injection therapy is to reduce muscle spasm and pain, allowing patients to return to a more productive, independent lifestyle.
Approved by the FDA in 1989, the treatment originated in the mid-1980s, when a ophthalmologist used it to treat two eye muscle disorders: blepharospasm and strabismus. For more information about blepharospasm, you can visit www.blepharospasm.org.
Botulinum toxin therapy works by interrupting communication between the muscle and the nerve receptors, blocking the release of a chemical called acetylcholine, which carries messages between nerves cells. Small doses of sterilized toxin are injected into the affected muscles blocking the response, which would otherwise signal the muscle to contract. There are 8 different serotypes of botulinum toxin- A, B, C, C1 D, E, F, and G. Types A and B are now in use. Serotype C and F have been used, but have proven not to be of great benefit - effects lasting only approximately 4 weeks or so.
Simply said, botulinum toxin relaxes the overactive muscles. It does so by interrupting electrical transmissions between the nerve and the muscle at a place where they come together, the neuromuscular junction. This is also called “chemodenervation”.
To learn more about how botulinum toxin works, visit this link:
Botulinum Toxin at How Stuff Works
The injections need to be repeated every three to four months because neurons generate new nerve endings that reactivate the dystonia. Booster injections should be avoided to minimize the risk of antibody formation to the toxin, which then renders the toxin ineffective. Nor should the toxin be mixed with other agents.
Research on the two main types, botulinum toxin type A, (Botox Cosmetic) and botulinum type B (Myobloc) available for use in the U.S. indicate that the treatment is relatively safe when given by a qualified neurologist. To find a qualified Center providing dystonia care, visit our Find a Top Center webpage today.
Dosing Guidelines
In patients with torticollis, about 100 to 400 U of botulinum toxin is injected into neck muscles. Onset of action takes about 3 to 5 days, and improvement is usually seen in 80% to 90% of patients. The main side effects are mild dysphagia and occasionally some difficulty keeping the head up if posterior muscles are overly weakened. For more information on torticollis, please visit the Spasmodic Torticollis website and Torticollis.org.
Blepharospasm requires injection of botulinum toxin into the orbicularis oculi muscle surrounding the eye, starting with a dose of 5 to 10 U per eye. Benefit usually occurs in at least 85% to 95% of patients within 5 to 7 days, with the main side effects being transient ptosis, difficulty closing the eye, diplopia, blurred vision, and a change in tearing.
Adductor spasmodic dysphonia patients are given botulinum toxin injections (0.5 to 5 U) into the vocal cords. Between 90% and 95% of patients note improvement in 1 to 3 days. Transient side effects include dysphagia and a breathy voice.
For jaw dystonia, botulinum toxin is injected into the masseter and temporalis muscles for jaw-closing dystonia and the digastric and pterygoid muscles for jaw-opening dystonia. Patients with writer’s cramp and limb dystonia require injections tailored to their specific dystonic symptoms.
According to the FDA, possible other side effects include: headache, respiratory infection, flu syndrome and nausea. Also, they recommend that the lowest effective dose should be used. Some patients experience temporary weakness in the group of muscles being treated. For example as mentioned above, ptosis (drooping eyelid) can develop after treating blepharospasm.
Source: PostGraduate Medicine, 2000 (Adler, C)
Some patients develop antibodies to the toxin with time, rendering the treatment ineffective. However, a second form of the toxin, Myobloc, is being used for patients who are resistant to botulinum toxin type A.
For more information on MyoBloc and dosing guidelines, please visit their website at myobloc.com.
Information on Botox can be found at www.medicalbotox.com
Additional Links and Stories:
- Is Botox Addictive?
- What about Pain and Dystonia?
- According to http://www.painmed.com in a study conducted at the Pain Evaluation & Treatment Center in Tulsa, Okla., 70 percent of patients with myofascial pain in the back and extremities who received botulinum injections over a two-year period reported “good” (15.5 percent) to excellent(54.5 percent) pain relief lasting an average of 2.5 to 3.6 months. Ten percent were pain-free after one year.
- Pitting Pain with Poison?
- Need Help Keeping Track of Your Injections? Download our Tracking Toxin Form listed below.
- Need Help Comparing the Side-effects of botulinum toxin ? Download our Toxin Side-Effect Chart listed below.
- MyoBloc : http://www.solsticeneuro.com
- Botox : http://www.BotoxMedical.com
- For information about the new upcoming N201 Neurotoxin Trials, go to our Nt201 webpage. This is the new Xeonim Toxin by Merz, Inc.
- New information about the upcoming PurTox by Mentor Corp. is to be released as they plan on branching out from the cosmetic arena to the Cervical dystonia arena in 2008-9. More news to follow.
- A new purified form of Botulinum Toxn, made by Allergan , will be undergoing clinical trials in 2008.
Botulinum Toxin Side-effect Chart
Report on toxin side-effects
Toxin Chart (pdf format )
Keeping Track of Botulinum Toxin Injections
A monitoring sheet for toxin injection sessions ( dosing, units, side-effects etc. )
Tracking Toxin Effects (pdf format )
More Detailed Information about Botulinum Toxin :
Source : www.medscape.com . You must register onto Medscape in order to read the above #6 Article. It is excellent !
Copyright.c4d.2007-8.