Botulinum Toxin (BOTOX) Treatment for Dystonia

Overview

Botulinum toxin injections are the treatment of choice for patients with cervical dystonia. The toxin is injected into the overactive muscles to the overactive muscles to result in selective weakening of the muscles just along the normally active muscles to bring the head to a more normal position. The effect comes on gradually over several days with peak effect in approximately two weeks. The benefit lasts on average for about 12 weeks. 80 to 90 percent of patients with focal dystonia are significantly improved with Botox injections. Patients with cervical dystonia experience a reduction in neck pain, abnormal head positioning, neck stiffness, and tremor/jerking, and are better able to turn the head. Patients with eye twitching or involuntary eye closure (blepharospasm) are substantially improved in 80 to 90 percent of cases, resulting in improvement in the ability to read, drive, and carry out day-to-day activities.

Writer’s cramp and other forms of limb dystonia may interfere with only one specific task or with many different tasks requiring manual dexterity. Selective injections can improve the use of the hands for writing, playing an instrument, typing or other activities.

Treatable Symptoms

  • Cervical dystonia – Abnormal neck posturing, often with superimposed jerky movements, may cause pain and embarrassment, and interfere with work, driving and social activities.
  • Blepharospasm – Eye twitching and involuntary eye blinking can interfere with reading, driving and many other day-to-day activities. These symptoms are commonly worse when patients are outside in sunlight.
  • Limb dystonia – Abnormal hand posturing may be task specific, sometimes occurring only when the patient is writing (writer’s cramp) or performing some other fine dexterous activity, such as typing or playing a musical instrument. The abnormal hand posturing may make it difficult or impossible to accomplish these tasks.

Treatment Method

When botulinum toxin is injected into the overactive muscle, it targets the nerve endings responsible for signaling muscle contraction. Once absorbed by the nerve ending, the toxin disrupts a crucial protein involved in releasing acetylcholine, the neurotransmitter that signals muscle movement. Consequently, communication between the nerve ending and the overactive muscle is hindered, leading to temporary weakening of the muscle and a reduction in involuntary movements and spasms. Although the effect is not permanent, as the nerve ending regenerates the necessary protein over time, allowing communication to resume, the symptomatic improvement diminishes.

Botulinum toxin is administered directly into the overactive muscles, such as those causing foot cramps or eye twitching, or into the salivary glands for drooling. The onset of effect is gradual, typically taking several days, with peak efficacy occurring around two weeks post-injection. The beneficial effects persist for approximately three months before gradually diminishing. Consequently, injections are repeated at three-month intervals to sustain the ongoing benefits.

Prognosis When Untreated

Dystonia usually slowly worsens over 2 to 3 years, and thereafter continues as a chronic disability. Remission is uncommon, occurring in less than 5 percent of cases.

Prognosis With Treatment

Botulinum toxin (Botox) injections effectively treat cervical dystonia in between 80-90 percent of patients, resulting in improvement in pain, neck position and quality of life. The injections can occasionally cause mild trouble swallowing or excessive neck weakness, but such side effects are typically mild and short lived. Injections are customized for each individual patient with respect to the specific muscles and the specific doses used, to maximize the benefits and to reduce the chance of any adverse effects.

Oral medications are helpful in less than 25 percent of patients, and rarely result in the immediate improvement seen with botulinum toxin injections. In patients with severe and more widespread dystonia (generalized dystonia), deep brain stimulation may provide additional therapeutic benefit.

Blepharospasm is improved with botulinum toxin injections in 80 to 90 percent of patients. Drooping of the eyelids or dry eyes may occur as adverse effects. If these side effects occur, they are usually mild and go away within 2 or 3 weeks. The specific pattern and dose of the injection into the muscles responsible for eye closing is customized in order to maximize benefits and minimize adverse effects.

Task specific limb dystonia (e.g. writer’s cramp or musician’s cramp) can be improved with highly customized injections of small amounts of Botox to selectively weaken the overactive muscles, without causes excessive weakness or reducing dexterity. When done by a highly experienced physician, this improves function in more than 75 percent of patients. Very low doses are typically needed in order to prevent grip weakness or impairment of other tasks.

Botulinum toxin injections are the first line and most effective treatment for 80 to 90 percent of patients with dystonia.

Botulinum toxin injections are the treatment of choice for patients with cervical dystonia.  The toxin is injected into the overactive muscles to the overactive muscles to result in selective weakening of the muscles just along the normally active muscles to bring the head to a more normal position.  The effect comes on gradually over several days with peak effect in approximately two weeks. The benefit lasts on average for about 12 weeks.

When the botulinum toxin is injected into the overactive muscle, it is taken up by the nerve ending which supplies the signal to the muscle to contract. Once inside the nerve ending, the toxin breaks down a protein which is necessary for the release of acetylcholine by the nerve ending. Acetylcholine acts as a signal from the nerve ending to the muscle to contract. The end result is that the toxin prevents the communication from the nerve ending to the overactive muscle resulting in temporary weakening of the overactive muscle reducing involuntary movement and muscle spasm. The effect is not permanent and the nerve ending eventually regenerates the protein which has been broken down by the botulinum toxin in the nerve ending that prevents release of the acetylcholine signal from the nerve ending to the muscle. When this important signaling protein is regenerated, the nerve ending can communicate with the muscle and the improvement of symptoms goes away.

There are two major forms of botulinum toxin, Type A and Type B. Type A botulinum toxins are used more commonly and the name brands are Botox, Dysport, and Xeomin. The name brand of Type B botulinum injection is Myobloc.  Type A and Type  B toxins work similarly, except that the type A toxins break down a different protein in nerve endings than does Type B toxin. The different forms of botulinum toxin have similar benefits and adverse effects. The effect of botulinum toxin injection is temporary and as a result patients need periodic injections.  A very small percentage of patients, perhaps 1 or 2%, may develop antibodies to one type of botulinum toxin so that injections are no longer effective.  If this occurs, patients may be switched from one type of toxin to another type of toxin.

The selection of the muscles and the dose that each muscle receives when botulinum toxin injections are performed must be customized based on the pattern and severity of abnormal movements as well as the size of the involved muscles, and the patient’s response to previous sets of injections.  Patients need to undergo careful examination of what muscles to inject and the specific doses should be determined.

Injections are distributed amongst the various muscles, customized and based on the patient’s pattern of abnormal movements. EMG guidance is often used to help localize the overactive muscles.  EMG stands for electromyography and is a neurophysiologic method by which the electrical activity of muscle activity can be recorded.

After injections are performed, the onset of effect occurring gradually over a few days with a peak effect in approximately two to four weeks. The average duration of improvement of symptoms is 12 weeks, though there is substantial variability from patient-­‐to-­‐patient.  About 80% of patients experience significant improvement in abnormal neck posturing and pain.

The main effect of the botulinum toxin injection is to produce selective muscle weakness.  Excessive weakness may occur, resulting in a floppiness of the head and more difficulty bringing the head up to neutral when the head is flexed or bringing the head forward when the head is extended such as when liYing the head off the pillow when in bed. Dry mouth can occur due to spread of the toxin to the salivary glands.  Occasional patients may experience transient flu-­‐like symptoms.  Pain may occur at the injection site due to the mechanical effect of placing a needle in different muscles.  Injection site pain typically lasts only one or two days and is usually improved with taking simple pain relievers such as Tylenol or ibuprofen. Excessive muscle weakness and dry mouth typically also improves over a few weeks.

Botulinum Toxin (BOTOX) Treatment for Dystonia

Will Botulinum Toxin Injections (Botox) Help Me?

80 to 90 percent of patients with focal dystonia are significantly improved with Botox injections. Patients with cervical dystonia experience a reduction in neck pain, abnormal head positioning, neck stiffness, and tremor/jerking, and are better able to turn the head. Patients with eye twitching or involuntary eye closure (blepharospasm) are substantially improved in 80 to 90 percent of cases, resulting in improvement in the ability to read, drive, and carry out day-to-day activities.

Writer’s cramp and other forms of limb dystonia may interfere with only one specific task or with many different tasks requiring manual dexterity. Selective injections can improve the use of the hands for writing, playing an instrument, typing or other activities.

Treatable Symptoms

  • Cervical dystonia – Abnormal neck posturing, often with superimposed jerky movements, may cause pain and embarrassment, and interfere with work, driving and social activities.
  • Blepharospasm – Eye twitching and involuntary eye blinking can interfere with reading, driving and many other day-to-day activities. These symptoms are commonly worse when patients are outside in sunlight.
  • Limb dystonia – Abnormal hand posturing may be task specific, sometimes occurring only when the patient is writing (writer’s cramp) or performing some other fine dexterous activity, such as typing or playing a musical instrument. The abnormal hand posturing may make it difficult or impossible to accomplish these tasks.

Treatment Methods

Botulinum toxin is injected specifically into the overactive muscles causing the foot cramps or eye twitching, or into the salivary glands for drooling. The effect comes on gradually over several days, with the peak effect reached in approximately 2 weeks. The benefit lasts for about 3 months. As a result, injections are repeated at 3 month intervals to maintain ongoing benefits.

Prognosis When Untreated

Dystonia usually slowly worsens over 2 to 3 years, and thereafter continues as a chronic disability. Remission is uncommon, occurring in less than 5 percent of cases.

Prognosis With Treatment

Botulinum toxin (Botox) injections effectively treat cervical dystonia in between 80-90 percent of patients, resulting in improvement in pain, neck position and quality of life. The injections can occasionally cause mild trouble swallowing or excessive neck weakness, but such side effects are typically mild and short lived. Injections are customized for each individual patient with respect to the specific muscles and the specific doses used, to maximize the benefits and to reduce the chance of any adverse effects.

Oral medications are helpful in less than 25 percent of patients, and rarely result in the immediate improvement seen with botulinum toxin injections. In patients with severe and more widespread dystonia (generalized dystonia), deep brain stimulation may provide additional therapeutic benefit.

Blepharospasm is improved with botulinum toxin injections in 80 to 90 percent of patients. Drooping of the eyelids or dry eyes may occur as adverse effects. If these side effects occur, they are usually mild and go away within 2 or 3 weeks. The specific pattern and dose of the injection into the muscles responsible for eye closing is customized in order to maximize benefits and minimize adverse effects.

Task specific limb dystonia (e.g. writer’s cramp or musician’s cramp) can be improved with highly customized injections of small amounts of Botox to selectively weaken the overactive muscles, without causes excessive weakness or reducing dexterity. When done by a highly experienced physician, this improves function in more than 75 percent of patients. Very low doses are typically needed in order to prevent grip weakness or impairment of other tasks.

Botulinum toxin injections are the first line and most effective treatment for 80 to 90 percent of patients with dystonia.

Botulinum toxin injections are the treatment of choice for patients with cervical dystonia.  The toxin is injected into the overactive muscles to the overactive muscles to result in selective weakening of the muscles just along the normally active muscles to bring the head to a more normal position.  The effect comes on gradually over several days with peak effect in approximately two weeks. The benefit lasts on average for about 12 weeks.

When the botulinum toxin is injected into the overactive muscle, it is taken up by the nerve ending which supplies the signal to the muscle to contract. Once inside the nerve ending, the toxin breaks down a protein which is necessary for the release of acetylcholine by the nerve ending. Acetylcholine acts as a signal from the nerve ending to the muscle to contract. The end result is that the toxin prevents the communication from the nerve ending to the overactive muscle resulting in temporary weakening of the overactive muscle reducing involuntary movement and muscle spasm. The effect is not permanent and the nerve ending eventually regenerates the protein which has been broken down by the botulinum toxin in the nerve ending that prevents release of the acetylcholine signal from the nerve ending to the muscle. When this important signaling protein is regenerated, the nerve ending can communicate with the muscle and the improvement of symptoms goes away.

There are two major forms of botulinum toxin, Type A and Type B. Type A botulinum toxins are used more commonly and the name brands are Botox, Dysport, and Xeomin. The name brand of Type B botulinum injection is Myobloc.  Type A and Type  B toxins work similarly, except that the type A toxins break down a different protein in nerve endings than does Type B toxin. The different forms of botulinum toxin have similar benefits and adverse effects. The effect of botulinum toxin injection is temporary and as a result patients need periodic injections.  A very small percentage of patients, perhaps 1 or 2%, may develop antibodies to one type of botulinum toxin so that injections are no longer effective.  If this occurs, patients may be switched from one type of toxin to another type of toxin.

The selection of the muscles and the dose that each muscle receives when botulinum toxin injections are performed must be customized based on the pattern and severity of abnormal movements as well as the size of the involved muscles, and the patient’s response to previous sets of injections.  Patients need to undergo careful examination of what muscles to inject and the specific doses should be determined.

Injections are distributed amongst the various muscles, customized and based on the patient’s pattern of abnormal movements. EMG guidance is often used to help localize the overactive muscles.  EMG stands for electromyography and is a neurophysiologic method by which the electrical activity of muscle activity can be recorded.

After injections are performed, the onset of effect occurring gradually over a few days with a peak effect in approximately two to four weeks. The average duration of improvement of symptoms is 12 weeks, though there is substantial variability from patient-­‐to-­‐patient.  About 80% of patients experience significant improvement in abnormal neck posturing and pain.

The main effect of the botulinum toxin injection is to produce selective muscle weakness.  Excessive weakness may occur, resulting in a floppiness of the head and more difficulty bringing the head up to neutral when the head is flexed or bringing the head forward when the head is extended such as when liYing the head off the pillow when in bed. Dry mouth can occur due to spread of the toxin to the salivary glands.  Occasional patients may experience transient flu-­‐like symptoms.  Pain may occur at the injection site due to the mechanical effect of placing a needle in different muscles.  Injection site pain typically lasts only one or two days and is usually improved with taking simple pain relievers such as Tylenol or ibuprofen. Excessive muscle weakness and dry mouth typically also improves over a few weeks.

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