Emory Physician Uses Botox Injections to Treat Spasticity Following
Stroke, Spinal Cord Injury and Brain Injury
Botulinum toxin type A, better known as Botox, has been used for more
than a decade to treat patients with conditions caused by overactive
muscles. Now, an Emory University physician is using Botox injections
to treat spasticity, or spastic paralysis, which often occurs following
a stroke, spinal cord injury or brain injury. Spasticity is usually
caused by damage to the portion of the brain or spinal cord that controls
voluntary movement.
"We've been using this treatment
on this population of patients over the past several years here at Emory
and we're seeing good results," says John Lin, M.D., assistant professor
of physical and rehabilitation medicine, Emory University School of
Medicine. "Botox injections are a middle-of-the-road treatment for spasticity.
We first try drug therapy and rehabilitation and if they don’t help,
we then turn to Botox. In many cases, this treatment works so well,
patients can continue the injections and avoid more complex treatments
such as surgery," Dr. Lin says.
Following a stroke, spinal
cord injury or brain injury, patients often develop spastic paralysis,
a form of paralysis in which the part of the nervous system that controls
coordinated movement of voluntary muscles becomes disabled. This leads
to stiffness and lack of mobility in these muscles. Doctors can now
inject Botox directly into the affected muscles to help loosen and relax
them. Muscles in the upper extremity usually respond the best to the
injections because they are smaller. Patients can be treated several
months or many years after their disability with these injections. "This
treatment is great for fine detail of muscle mobility and most any muscle
can be selected for treatment," says Dr. Lin. "However, Botox injections
are not recommended if one wants to treat a large group of muscles at
one time."
Results are usually seen
three to seven days following injections, with a peak effect at about
one month. The injections tend to last three to six months and repeat
injections are usually required. Most people continue to respond positively
to Botox injections, although some people develop a tolerance to the
drug and experience a diminished response over time. There are few side
effects to taking Botox, which makes taking the drug so desirable.
Botulinum toxin is a protein
that is produced by the bacterium Clostridium botulinum, once known
only as the culprit of the often fatal food poisoning known as botulism.
The bacterium causes muscle paralysis by blocking the release of the
neurotransmitter, acetylcholine. Normally, acetylcholine plays a vital
role in sending messages from the nerves to the muscles that tell the
muscles to move. The area where the nerve meets the muscle is called
the synapse, and a process called presynaptic release describes the
secretion of acetylcholine by the nerve cell. When the synaptic transmission
is blocked, the muscle to which that nerve is attached becomes paralyzed.
Botox injections block the transfer of acetylcholine, and in doing so,
temporarily alleviate muscle spasms caused by too much neural activity.
The use of Botox to treat
spasticity following stroke, spinal cord injury and brain injury is
through off-label use only, meaning the treatment has not been approved
for that specific purpose by the U.S. Food and Drug Administration (FDA).
However, off-label use of a medical treatment or device is acceptable
provided such use is based on sound and appropriate medical evidence
and judgment.
The FDA has approved the
use of Botox for cervical dystonia (involuntary, abnormal movements
or spasms in the neck), strabismus (crossed or misaligned eyes), blepharospasm
(uncontrolled, rapid eye blinking) and for cosmetic treatment of facial
wrinkles.
Most of the patients treated
with Botox injections at Emory have suffered a stroke about 60 percent.
Brain injuries make up about 30 percent and spinal cord injuries and
other disabilities make up 10 percent of treatment. "Day after day,
we see how well these injections are working for spasticity control,"
says Dr. Lin. "Because patients can regain mobility and use of their
limbs following an injury or set-back, the injections give an aspect
of independence to the patient, as well as comfort and care."
Dr. Lin knows all too well
about the importance of independence. A paraplegic for 11 years following
a ruptured aneurysm in his back, Dr. Lin is able to make a special connection
with his patients, some of whom suffer similar paralysis as he. After
his misfortune, he decided to go to medical school and become a doctor,
working specifically with patients in rehabilitation medicine. "My disability
helped me to figure out what I wanted to do with my life," says Dr.
Lin. "I thought I might be able to make a difference and give someone
that extra bit of encouragement they needed." |