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Getting TDD therapy for severe spasticity

Evaluation process

Start by seeking an evaluation by a doctor who specializes in spasticity management. Most doctors who specialize in spasticity treatment are neurologists or doctors of physical medicine and rehabilitation.

Make sure to have your related medical records sent to the specialist ahead of time.

A spasticity evaluation typically includes:

  • A questionnaire about your symptoms
  • Your medical history
  • A physical exam
  • Standard spasticity assessments

Am I a candidate for TDD therapy?

Your doctor will recommend a treatment plan based on the results of your evaluation.

Targeted drug delivery therapy may be considered if you have severe spasticity and:

  • Spasticity, spasms, or pain is interfering with function, care, positioning, or daily activities.

You must also meet these requirements to be eligible for a TDD pump:

  • Your body is large enough for an implanted pump.
  • You show a positive clinical response to the TDD screening test.
  • You are not hypersensitive or allergic to prescribed medication.
  • You do not have any infection at the time of pump placement.
  • If you had a traumatic brain injury, you must wait at least 1 year to be eligible for a TDD pump.
  • Oral medication isn't working well enough or is causing intolerable side effects such as fatigue or constipation.

Safety and effectiveness in pediatric patients below the age of 4 have not been established.

If you are a candidate for TDD therapy, the next step is a screening test to see if you would respond to this treatment.

Screening test

The screening test will show whether you will respond to treatment with TDD therapy. During the test, you receive a small, temporary dose of prescribed medication, and your response is monitored.

A test dose

The screening test may take place in a hospital or surgical center. Your doctor's office will tell you how to prepare for the test. You will also receive instructions on taking your oral spasticity medications.

During the test, the doctor will inject a small dose of prescribed medication into the space where fluid flows around your spinal cord. Your response will be monitored for at least 6 - 8 hours.

You may feel the effects in 30 minutes to an hour, and they typically last 4 to 8 hours. Afterward you will return to the same amount of spasticity you had before.

Possible temporary drug-related side effects of the screening test include loose muscles, nausea/vomiting, sleepiness, headaches, and dizziness. Be sure to tell your doctor if you experience any of these side effects. You should not have the screening test if you have an infection, hypersensitivity, or an allergy to the prescribed medication.

Test results

The screening test results are positive if the test dose significantly reduces your spasticity and improves range of motion.

During the screening test, your muscles may become only slightly looser or may become quite loose, weak, or "noodly." Either is a positive test result.

The screening test may impact your ability to walk because your muscles may become too loose. That's a positive test result, too, because you are responding to the prescribed medication. During treatment itself, the dose would be gradually adjusted so you are not too loose or too tight. Meanwhile, physical therapy can help you develop new muscle strength and gait patterns if you are currently walking.

Some people don't respond to the first test dose. If this happens, your doctor may give you a larger test dose on a different day. A third test may also be done if necessary. If none of the test doses loosen your muscles, you are not a candidate for a targeted drug delivery pump.

After the screening test, plan to meet with your doctor to discuss your test results, treatment options, and goals.


Placing the pump

Rendering of location of pump placement.

Intrathecal drug delivery

Placing the pump system usually takes approximately 2 hours. The procedure is most commonly done under general anesthesia, but there are alternatives if needed.

The surgeon will place the pump under the skin of your abdomen. One end of the catheter is then inserted into the fluid around the spinal cord, tunneled under the skin, and connected to the pump.

After the procedure, depending on your doctor's preference and hospital policy, a brief hospital stay may be recommended.

Any surgical procedure has inherent risks.  It is important to speak with your physician about them. Possible surgical complications include infection, meningitis, spinal fluid leak, paralysis, and headache.

While you heal

Follow your doctor’s instructions on activities, oral medication, and incision care.

After the procedure, your incisions may feel tender or uncomfortable. Your doctor may prescribe medication to relieve any pain caused by surgery and antibiotics to prevent infection.

Call your doctor immediately if you get a fever or see redness or swelling around the incision. Once you have healed, your incision site will not need special care.

Your doctor may recommend that you restrict activities for 6 to 8 weeks after the procedure. As you become more active, follow your doctor’s instructions about work, sex, travel, recreation, hobbies, and exercise.

Adjusting the dose

Your pump will be filled with prescribed medication during the implant procedure. Treatment begins when medication flows from the implanted pump through the catheter into the fluid surrounding the spinal cord.

Let your doctor know how you feel (e.g., are your muscles too loose, or not loose enough?) so dose adjustments can be made. It can take weeks, even months, to identify the dose and program that works best for you. This process (known as dose titration) takes time because TDD therapy isn't "one size fits all."

After a dose adjustment, you will usually see the effects in 6 to 8 hours and the maximum effect in one or two days. As your dose of prescribed medication increases, your doctor may slowly reduce your oral spasticity medicine.


Information on this site should not be used as a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.

Patient important safety information

When receiving TDD Therapy make sure you follow your clinician’s instructions closely. A sudden stop in therapy can result in serious prescribed medication withdrawal symptoms, such as high fever, changed mental status, muscle stiffness, and in rare cases, may result in the loss of function of many vital organs and death.

It is critical that your clinician be called right away if you experience any of these symptoms. Make sure you keep your scheduled refill visits so you don’t run out of medication. You should also know the early symptoms of prescribed medication withdrawal. Some people are at more risk than others for medicine withdrawal; speak with your clinician about this.


Q: What is severe spasticity?

A: Severe spasticity is a condition that results from an injury to or disease of the brain or spinal cord. Spasticity may make your muscles feel tight, stiff and difficult to move. With severe spasticity, you can experience stiffening of the muscles that makes your muscles feel like they are locked, or even jerk uncontrollably when you try to use them.

Q: What is TDD Therapy?

A: Targeted drug delivery is a treatment using prescribed medication that is delivered into the fluid around your spinal cord (intrathecal) to help manage severe spasticity. For long term treatment, the drug is placed into a pump that is surgically placed under the skin of your abdomen. The pump delivers prescribed medication through a small tube (catheter) into your spinal fluid. Your doctor can program the pump to deliver the appropriate daily dose for you. Before you can be considered for long term treatment, you must have a test dose to see how you respond to the drug when it is delivered in this way. After the test dose is done, your doctor will discuss the results with you and determine if you are an appropriate candidate for the therapy.

Q: Who is a candidate for TDD Therapy?

A: People who have severe spasticity resulting from conditions of the brain or spinal cord (such as multiple sclerosis, cerebral palsy, stroke, brain injury or spinal cord injury) may be candidates for TDD Therapy. If your spasticity is due to spinal cord injury or multiple sclerosis and is not controlled with medication taken by mouth or you have side effects that are not acceptable from oral medication taken to treat your spasticity, you may be a candidate. If you have had a brain injury due to trauma, you should wait for one year after your injury to be considered for TDD Therapy. Safety and efficacy in patients under the age of 4 has not been established.

Q: Who is not a candidate for TDD Therapy or a screening test dose?

A: If you are hypersensitive to prescribed medication, you should not use it. If you have an active infection, you should not have a screening test or implant until the infection has resolved. You should not receive TDD Therapy if you have a body size that is too small to hold the implantable pump.

Q: What do I need to know if I am using targeted drug delivery?

A: All patients and caregivers should receive information on the risks of the treatment. Your doctor should give you information of the signs and symptoms of receiving too much or too little medication (overdose or withdrawal) and what to do if you notice those symptoms.

Q: What can I do to prevent medication withdrawal or abrupt interruption of medication?

A: It is very important that you not miss refill appointments. If you plan to travel let your doctor know so that your refill can be scheduled so that you don’t run out of medication. If you are hospitalized for any reason near the time of your refill, you or your caregiver should let your doctor know before the refill date so that arrangements can be made to refill your pump. Not all hospitals have doctors that can refill pumps, so let your doctor know as soon as possible if it is near your refill date. You should be aware of what your pump alarms sound like. If you hear an alarm, contact your doctor immediately.

Q: What are the potential pump and catheter implant procedure complications?

A: The implanted pump and catheter are placed under the skin of the abdomen during a surgery. Some complications that you may experience with the implant surgery include infection, meningitis (infection of the lining of the brain and central nervous system), spinal fluid leak, paralysis, headache, swelling, bleeding, and bruising.

Q: What are the potential pump and catheter complications that can occur after implant?

A: Once the infusion system (the pump and the catheter) is implanted, device complications may occur that may require surgery to remove or replace the pump, catheter or catheter fragment. Some of these device complications may impact the flow of medication delivered, which may cause symptoms of overdose or withdrawal of prescribed medication.

Possible complications include an internal component failure which may result in a loss of therapy, or an inability to program the pump. The pump, catheter or catheter fragment could migrate within the body or erode through the skin. Tissue or an inflammatory mass may form at the tip of the catheter in the intrathecal space and may cause a loss of therapy or neurological impairment including paralysis. The catheter could leak, tear or become disconnected resulting in delivery of medication into the area under the skin where the pump is implanted and/or along the catheter path. The catheter could kink or become blocked resulting in no delivery of medication. The pump could stop because the battery has run out or because of a problem with one or more of its inner parts. Errors in locating the pump during the refill procedure can result in symptoms of overdose that may be serious or life-threatening.

Q: Can I undergo Magnetic Resonance Imaging (MRI) testing?

A: Under certain conditions, an MRI can be conducted with the pump. Always inform your doctor that you have an implanted infusion system before any medical or diagnostic procedure such as MRI or diathermy. Please ask your doctor to determine if the MRI scan can be used with the pump. The MRI will cause your pump to temporarily stop, which will suspend drug delivery during the MRI. The pump should resume normal operation and drug delivery after the MRI is complete. Your pump may also temporarily sound an alarm during the scan; the alarm should stop at the conclusion of the scan. Following your MRI, your doctor should check your pump to confirm that it is working properly.