Botox Intramuscular Injection

What is Botox?

Botox is short for botulinum (BAH-che-LINE-em) toxin type A. Botulinum is a kind of bacterium. Botox purified neurotoxin complex is a protein produced by the bacterium Clostridium botulinum. The effects of botulinum toxin have been known since the early 1900s, but the toxin has only just been discovered to help patients with spasticity.

Who Gets Botox Therapy?

Botox therapy is used to treat patients with spasticity that restricts function or causes pain. Usually, the spasticity affects muscles of the face, neck, arm, or leg.

Botox injection treatment is generally not advised for patients who are pregnant or breastfeeding, or for patients with certain diseases of the nerves and muscles.

How Does Botox Work?

Botox is a nerve impulse ‘‘blocker.’’ It attaches to nerve endings and prevents the release of chemical transmitters, which activate muscles. These chemicals carry the ‘‘message’’ from the brain that tells a muscle to contract. If the message is blocked, the muscle doesn’t spasm. Botox is given by injection directly into the affected muscles. This helps control side effects to other regions of the body. However, nerve endings usually grow new connections to muscles that have not yet been exposed to Botox. So, treatment may be repeated as often as every three months. Botox usually takes full effect within two to four weeks after injection.

How is Botox Therapy Done?

The clinical team helps the patient and family member or caregiver identify goals before treatment begins. The treatment is done as an outpatient procedure. The patient is first prepared for the procedure. Small electrodes are attached with tape to the patient’s skin over the affected muscle area. The electrodes are attached to an electromyography (eh-LEKtro-my-AWG-re-fee) machine (EMG).

The EMG is used to confirm needle location before the injection, to make sure the correct muscles are identified.

The doctor then asks the patient to move the muscle group. If the patient is unable to do this, the doctor will perform range-of-motion movements for the patient. This helps him or her get the most benefit from the injection.

The medicine is injected into the muscle using a small needle, which is attached to the EMG machine.

The doctor may inject small amounts of Botox into several locations along the muscle group or within many muscle groups. This helps maximize the benefits of the medicine.

How Much Botox Will I Get?

The amount of medicine you receive will depend on your degree of spasticity and which muscle groups are spastic. The maximum dose is less than 500 units per visit.

Botox therapy can be repeated as early as two to three months after the last injection, if you had good results and your goals were met.

After Treatment

It is important to understand that Botox is an effective, ongoing treatment for the relief of symptoms — it is not a cure. Because every patient is different, the degree of relief will vary from person to person. Patients should resume activity slowly and carefully after Botox injection. Your doctor may recommend physical or occupational therapy after injection for best results.

The most common side effects include discoloration, redness, pain, or discomfort at the injection site. The effects of Botox may be increased before a patient’s maintenance dose is set. The effects may also be increased with the use of certain antibiotics or other drugs that interfere with the body’s nerve or muscle systems.


A follow-up appointment will be made four weeks after your first Botox injection to evaluate its effects and to make further treatment recommendations if needed.

If you have any questions about this therapy or other therapies for spasticity, call the Spasticity Evaluation and Treatment Center at (412) 647-2123.






Pittsburgh, PA, USA UPMC.com