In this didactic, we will cover intrathecal baclofen therapy for the treatment of spasticity. I am Andrea Toomer, a physiatrist at the Coloquia Neurological Clinic and with the LSU Department of Neurosurgery. I am a speaker and an advisor for a number of pharmaceutical and device companies. In this lecture, we will review the indications for intrathecal baclofen therapy. We will discuss appropriate patient selection. We will outline contraindications and precautions related to intrathecal baclofen therapy. We will discuss the process of the intrathecal baclofen screening test and we will review MRI compatibility and varying MRI protocols with varying intrathecal baclofen devices. Intrathecal baclofen is indicated for problematic diffuse severe spasticity. We are talking about problematic spasticity that interferes with comfort and or function and that increases the difficulty with caregiving. We're talking about spasticity that is diffuse, affecting multiple parts of the body. And we're talking about spasticity that we cannot easily control with oral medications. There are special considerations when evaluating patients who are appropriate for intrathecal baclofen therapy. In the case of ambulatory patients, reducing spasticity will certainly impact gait. You could see an improved ambulation quality and ambulation speed by reducing spasticity. Additionally though, reducing spasticity could impair ambulation in patients who rely on that increased muscle tone for support. It's important to understand that patients will need ongoing physical therapy in conjunction with intrathecal baclofen. This is particularly important in ambulatory patients. When considering pediatric populations, it's important to recognize that early treatment of spasticity can reduce the need for orthopedic procedures down the line by preventing contracture development. As we discussed, intrathecal baclofen will decrease spasticity and can impact gait. Here we see a patient ambulating at her baseline and we see her ambulating two hours after being administered an intrathecal baclofen bolus dose. The patient had quite a profound response, making her feel unsteady and she actually requires meniscus to ambulate. Don't worry, we will revisit her case in just a few moments and we will evaluate how she does four hours after her intrathecal baclofen bolus dosing. When evaluating patients who are possible candidates for intrathecal baclofen therapy, it's very important to determine whether or not the patients and the caregivers have the ability to adhere to the medical regimen. It's very important that patients are able to attend refill appointments. It's also very important that patients and their caregivers are able to monitor for the potential side effects or signs and symptoms of baclofen overdose and withdrawal. There are sometimes psychosocial and financial barriers that prevent patients from being good candidates for intrathecal baclofen therapy. It's also very important when evaluating patients and determining if moving forward with intrathecal baclofen therapy is the most appropriate option. It's important to determine that the patient has appropriate, realistic, short-term and long-term goals for intrathecal baclofen therapy. There are contraindications to intrathecal baclofen therapy. A hypersensitivity to baclofen is an absolute contraindication. Pumps should not be implanted in the midst of an active infection. It is also an absolute contraindication if the pump cannot be accommodated due to the patient's small body habitus. Relative contraindications would include the patient or caregivers having unrealistic goals about what intrathecal baclofen therapy will allow the patient to achieve, if the patient has unmanageable mental health issues, or if the patient has psychosocial factors such as unreliable family support, unreliable transportation, inability to maintain refill appointments, inability to identify symptoms of baclofen overdose or withdrawal. All of those factors would make the patient a relatively poor candidate for intrathecal baclofen therapy. Once we have determined that the patient is appropriate for intrathecal baclofen therapy, the next step is to perform a screening test. The intrathecal baclofen screening test is performed through a lumbar puncture using sterile technique. The standard intrathecal baclofen screening test dose is a 50-microgram bolus. However, a screening test dose lower than 50 micrograms may be appropriate in some clinical scenarios. Patient evaluation is a very important part of the intrathecal baclofen screening test. Objective measurement of spasticity should be performed, such as performing a modified Ashworth. The patient's strength and range of motion should be evaluated. The screening test evaluation should include functional evaluations, such as evaluating the patient's sitting position, the patient's transfers, and in the case of ambulatory patients, a timed up-and-go or a timed distance ambulation. Here we see assessment of the patient's spasticity during an intrathecal baclofen screening test using the modified Ashworth scale. On the left, we see her baseline assessment. The patient has a modified Ashworth of three for the knee flexors. She has a modified Ashworth of two for the knee extensors. She has a modified Ashworth of one plus for the ankle dorsiflexors. On the right, we see her assessment after she has been administered an intrathecal baclofen bolus. She has modified Ashworth of one plus for the knee flexors. She has modified Ashworth of one for the knee extensors. And she has a modified Ashworth of zero for the ankle dorsiflexors. The timed up-and-go is one way to objectively measure gait during an intrathecal baclofen screening test. The patient is instructed to stand, walk a particular distance, turn around, and return to the chair. This is our same patient that we saw previously who had a profound response to intrathecal baclofen at two hours. At her baseline, we see she ambulates with a timed up-and-go of 20 seconds. At four hours after administration of intrathecal baclofen, her timed up-and-go is 16 seconds. So although she had a profound response and her ambulatory ability declined at the two-hour mark, at four hours after administration of intrathecal baclofen, her ambulation has improved. During the screening test, it's also important to obtain the patient and the caregiver's subjective information. Subjective measures can include spasm intensity, spasm frequency, and pain scale. A screening test would be considered positive if we can show an objective improvement in spasticity, an objective improvement in function, and we can show that there are goals for intrathecal baclofen therapy. Objective improvement in spasticity and function, such as improvement in a modified Ashworth score, in ambulation speed, ambulation quality, or improvement in sitting position and caregiver tasks would all be very important to document and would all show a positive response to intrathecal baclofen. The goals for intrathecal baclofen therapy can be both active and or passive goals. The medical team, the patient, and the family members all must take part in goal setting. We would consider a patient a good candidate for intrathecal baclofen therapy if the patient has a positive response to the screening test, if the patient and caregivers have realistic goals, and the patient and caregivers have ability to maintain follow-up appointments and to participate in ongoing physical and occupational therapy. Intrathecal baclofen therapy is delivered through a programmable pump. The dosing is titrated according to the patient response. Concurrent therapy interventions, including bracing, oral medications, and or toxin injection should be utilized to maximize spasticity control and to maximize functional improvement. There are two FDA approved intrathecal baclofen devices. One is the Medtronic Synchromed II pump and the other is the Floonix Prometra II pump. Both devices are MRI conditional. However, the MRI protocols vary very widely between these two devices. It is very important for physicians to understand the different MRI protocols for these two devices. The Medtronic Synchromed II pump is MRI conditional. It is designed to stop programmed therapy during an MRI scan and to resume programmed therapy immediately after the MRI scan. No pump interrogation is necessary prior to MRI. The reservoir does not need to be emptied prior to MRI. The pump should be interrogated after the MRI to ensure that drug delivery has resumed. The Floonix Prometra II pump is also MRI conditional. However, the drug reservoir must be emptied prior to the MRI. The Prometra II protocol for MRI indicates that we should inquire the pump prior to MRI, program the pump, setting it to a flow mode of constant flow at a rate of 0.0 micrograms per day. Repeat the pump inquiry and confirm a constant flow rate of 0.0 micrograms per day. Then access the pump and empty the drug reservoir. Following the MRI, the flow-activated valve will be closed. This prevents further drug delivery until the pump is manually reset. Inquire the pump with the programmer and confirm that the settings are unchanged from the pre-MRI settings. You should then access the drug reservoir and aspirate. A significant volume return of greater than one milliliter could indicate that the pump inlet outlet valve is open. In this case, you would not proceed with the pump refill. Assuming that a significant volume return is not obtained, you would then proceed with the pump refill and program the pump to the desired settings. Which of the following is correct concerning intrathecal baclofen therapy? A, ambulatory patients are not good candidates for intrathecal baclofen therapy as they will have weakness and a loss of ambulatory ability. B, the use of intrathecal baclofen therapy negates the need for physical therapy and bracing. C, patient selection involves ensuring that patients have the social supports necessary to make refill appointments. Or D, both FDA approved intrathecal pumps are unconditionally approved for MRI use. The correct answer is C. Certainly, intrathecal baclofen therapy will have an impact on gait. By reducing spasticity, gait quality and speed may improve. Reducing spasticity may also impair ambulation in patients who rely on spasticity for stability and support in the lower extremities. Intrathecal baclofen therapy can be an effective tool in improving ambulatory function in certain patients. Rehabilitative therapy should be applied concomitantly in ambulatory patients. Patient, family and caregiver education is a crucial process in intrathecal baclofen therapy. Centers must create a supportive, instructive environment that utilizes all available resources to accomplish the educational goals effectively. Goal setting is necessary for patients and clinicians to approach the utilization of intrathecal baclofen therapy in a meaningful and effective way. Both the fluonics and the Medtronic pumps are MRI conditional and specific protocols must be followed to ensure patient safety with MRIs. Patients with diffuse severe spasticity are potential candidates for intrathecal baclofen therapy. Appropriate patient selection and goal setting is essential for successful outcomes with intrathecal baclofen therapy. The intrathecal baclofen screening test allows observation of the patient's response to determine appropriate ITB therapy candidates. There are two FDA approved intrathecal baclofen devices, both of which are MRI conditional. However, it is important to recognize the MRI protocols and follow the appropriate protocol for each device.

intrathecal baclofen therapy

spasticity treatment

MRI compatibility

patient selection

physical therapy