About Intrathecal Baclofen Therapy
ITB TherapySM is a treatment option used to manage severe spasticity of cerebral or spinal origin.
ITB Therapy (intrathecal baclofen therapy) for the management of severe spasticity uses an implantable infusion system to deliver precise amounts of Lioresal® Intrathecal (baclofen injection) directly to the intrathecal space via a surgically implanted infusion pump and catheter.
Indications and Contraindications
Lioresal Intrathecal (baclofen injection)
Lioresal® Intrathecal is indicated for use in the management of severe spasticity. Patients should first respond to a screening dose of intrathecal baclofen prior to consideration for long term infusion via an implantable pump. For spasticity of spinal cord origin, chronic infusion of Lioresal Intrathecal via an implantable pump should be reserved for patients unresponsive to oral baclofen therapy, or those who experience intolerable CNS side effects at effective doses. Patients with spasticity due to traumatic brain injury should wait at least one year after the injury before consideration of long term intrathecal baclofen therapy. Lioresal Intrathecal is intended for use by the intrathecal route in single bolus test doses (via spinal catheter or lumbar puncture) and, for chronic use, only in implantable pumps approved by the FDA specifically for the administration of Lioresal Intrathecal into the intrathecal space.
SynchroMed II Infusion Pump
US: Chronic intrathecal infusion of Lioresal Intrathecal (baclofen injection) for the management of severe spasticity. Outside of US: Chronic infusion of drugs or fluids tested as compatible and listed in the product labeling.
Lioresal Intrathecal (baclofen injection)
Hypersensitivity to baclofen. Lioresal Intrathecal is not recommended for intravenous, intramuscular, subcutaneous, or epidural administration.
SynchroMed II Infusion Pump
Infection; implant depth greater than 2.5 cm below skin; insufficient body size; spinal anomalies; drugs with preservatives, drug contraindications, drug formulations with pH ≤3, use of catheter access port (CAP) kit for refills or of refill kit for catheter access, blood sampling through CAP in vascular applications, use of Personal Therapy Manager to administer opioid to opioid-naïve patients or to administer ziconotide.
Diagnosis and Treatment
Spasticity is an abnormal increase in muscle tone caused by injury of upper motor neuron pathways regulating muscles. Injury or disease of the central nervous system may cause spasticity. Spasticity may be a result of multiple sclerosis (MS), cerebral palsy (CP), stroke, brain injury, or spinal cord injury.
Although the pathophysiology of spasticity is not completely understood, it is most commonly defined clinically as "...a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes ('muscle tone') with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex, as one component of the upper motor neuron syndrome."1 The velocity-dependent nature of spasticity distinguishes it from other forms of hypertonia, such as dystonia and rigidity.2
Severe spasticity can have a distressing effect on function, comfort, and care giving. It may result in musculoskeletal complications, incoordination, loss of function, pain, and permanent muscle shortening or contracture.
Treating severe spasticity may:
- Improve gait, hygiene, activities of daily living, and ease of care
- Decrease spasm frequency, pain, and fatigue
- Promote tone reduction, increased range of motion, and joint position
- Increase patient mobility
- Complement other treatments, such as physical therapy, occupational therapy, and speech therapy
For patients with severe spasticity, enhancing their mobility, self-care abilities, and independence are significant achievements. To reach these milestones, effective therapy is necessary. Spasticity can be treated separately from the patient’s primary underlying condition.
It can be difficult to effectively control severe spasticity. While physical rehabilitation and oral pharmacologic treatments work for many patients, some patients may not experience enough relief using these treatments alone. In addition, some patients encounter intolerable side effects from systemic medications. Patients who are unresponsive to oral baclofen or who experience intolerable central nervous system (CNS) side effects from oral medications may benefit from ITB TherapySM. ITB Therapy can significantly decrease severe spasticity3-11 and spasms.4, 9-11
The intrathecal baclofen therapy system consists of a programmable pump, an intrathecal catheter, and an external programmer. The pump is surgically implanted in the patient's abdominal area the catheter tip is placed in the intrathecal space, and the catheter is connected to the pump. Once implanted, the pump and catheter deliver Lioresal® Intrathecal (baclofen injection) directly to the patient's spinal fluid, where it can act directly in the spinal fluid. The Medtronic SynchroMed® II infusion pump used for ITB Therapy can be noninvasively programmed to deliver a range of infusion rates, in a variety of dosing patterns.
ITB Therapy delivers baclofen directly into the intrathecal space, thereby bypassing the blood-brain barrier. As a result, only a fraction of the oral dose is needed to produce efficacy while minimizing systemic side effects.12
Three features of ITB Therapy are particularly desirable and important to most patients:
- Graduated Control of Spasticity and Flexible Dosing Patterns – Use of a programmable infusion system for ITB Therapy permits clinicians to titrate dosage, providing graduated control of spasticity that not only meets the needs of individual patients at the time of implant, but that also can be adjusted whenever a change in dose is clinically indicated. It also enables physicians to deliver the drug on a variable schedule, e.g., providing greater spasticity control at night than during the day.16
- Effective Treatment for Upper and Lower Extremity Spasticity – ITB Therapy reduces upper and lower extremity spasticity.5, 6, 13 Treatment may reduce spasticity and promote function among quadriplegic/tetraplegic as well as diplegic patients.6, 14-15
- Reversibility of Treatment – Patients and their families can be reluctant to undergo destructive neurosurgical procedures. ITB Therapy may be considered an alternative to such procedures.
Baclofen is a structural analog of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), and may exert its effects by stimulation of the GABAB receptor subtype. However, the precise mechanism of action of baclofen as a muscle relaxant and antispasticity agent is not fully understood. Baclofen inhibits both monosynaptic and polysynaptic reflexes at the spinal level, possibly by decreasing excitatory neurotransmitter release from primary afferent terminals, although actions at supraspinal sites may also occur and contribute to its clinical effect.12
In people, as well as in animals, baclofen has been shown to have general CNS depressant properties as indicated by the production of sedation with tolerance, somnolence, ataxia, and respiratory and cardiovascular depression.12
- Lance JW: Synopsis. In: Feldman RG, Young RR, Koella WP, eds. Spasticity: Disordered Motor Control. Chicago: Year Book Medical Publishers. 1980:480 485.
- Sanger TD, Delgado MR, Gaebler-Spira D, Hallet M, Mink JW; Task Force on Childhood Motor Disorders. Classification and definition of disorders causing hypertonia in childhood. Pediatrics. 2003;111(1):e89-97.
- Francisco GC, Boake C. Improvement in walking speed in poststroke spastic hemiplegia after intrathecal baclofen therapy: a preliminary study. Arch Phys Med Rehabil. 2003;84(8):1194-1199.
- Meythaler JM, Guin-Refroe S, Brunner RC, Hadley MN. Intrathecal baclofen for spastic hypertonia from stroke. Stroke. 2001;32(9):2099-2109.
- Ivanhoe CB, Francisco GE, McGuire JR, Subramanian T, Grissom SP. Intrathecal baclofen management of poststroke spastic hypertonia: implications for function and quality of life. Arch Phys Med Rehabil. 2006;87(11):1509–1515.
- Gilmartin R. Intrathecal baclofen for management of spastic cerebral palsy: multicenter trial. J Child Neurol. 2000;15(2):71-77.
- Penn RD. Intrathecal baclofen for spasticity of spinal origin: seven years of experience. J Neurosurg. 1992;77(2):236-240.
- Albright AL, Gilmartin R, Swift D, Krach LE, Ivanhoe CB, McLaughlin JF. Long-term intrathecal baclofen therapy for severe spasticity of cerebral origin. J Neurosurg. 2003;98(2):291-295.
- Coffey RJ, Cahill D, Steers W. Intrathecal baclofen for intractable spasticity of spinal origin: results of a long-term multicenter study. J Neurosurg. 1993;78(6):226-232.
- Ordia JI, Fischer E, Adamski E, Chagnon KG, Spatz EL. Continuous intrathecal baclofen infusion by a programmable pump in 131 consecutive patients with severe spasticity of spinal origin. Neuromodulation. 2002;5(1):16-24.
- Becker R, Alberti O, Bauer BL. Continuous intrathecal baclofen infusion in severe spasticity after traumatic or hypoxic brain injury. J Neurol 1997; 224(3): 160-166
- Lioresal® Intrathecal (baclofen injection) Drug Package Insert.
- Guillaume D, Van Havenbergh A, Vloeberghs M, Vidal J, Roeste G. A clinical study of intrathecal baclofen using a programmable pump for intractable spasticity. Arch Phys Med Rehabil. 2005;86:2165-2171.
- Hoving MA, van Raak EP, Spincemaille GH, Palmans LJ, Becher JG, Vles JS. Efficacy of intrathecal baclofen therapy in children with intractable spastic cerebral palsy: a randomised controlled trial. Eur J Paediatr Neurol. May 2009;13(3):240-246.
- Shilt JS, Reeves S, Lai LP, et al. The outcome of intrathecal baclofen treatment on spastic diplegia: Preliminary results with a minimum of two year follow up. J Ped Rehab Med. 2008;255-61.
- Natale M, Mirone G, Rotondo M, Moraci A. Intrathecal baclofen therapy for severe spasticity: Analysis on a series of 112 consecutive patients and future prospectives. Clin Neurol Neurosurg. 2012;114:321-325.
The management of ITB TherapySM has a sequence of phases. Guides and tools for each phase are available on the ITB Resource Center.
First the clinician assesses the spasticity of a current or referred patient. The assessment includes a patient questionnaire and interview, a physical examination, spasticity assessment, and a review of potential goals that the patient, caregiver, and clinician hope to achieve. The clinician then identifies appropriate treatment options and develops a treatment plan with the patient and caregiver, as appropriate. If the patient has severe spasticity and the clinician is recommending the screening test for ITB Therapy, the benefits and risks of the test are discussed.
The ITB screening test helps physicians and patients determine if the patient with severe spasticity will respond to ITB Therapy. A screening test is performed by delivering a bolus dose of baclofen into the intrathecal space through a single lumbar puncture injection. This procedure may be done in a hospital setting or physician’s office. The results are considered positive when the patient's spasticity is significantly reduced, shown by specific spasticity evaluations and improved range of motion. Possible adverse events of the screening test are drug related and include hypotonia, somnolence, nausea, vomiting, headaches, and dizziness. The screening test is contraindicated in the presence of active infection and in patients who demonstrate hypersensitivity to oral baclofen. The patient must be monitored closely in a fully equipped and staffed environment during the screening test. Resuscitative equipment should be immediately available for use in case of life threatening side effects.
Implant of Pump System
Specially trained neurosurgeons, orthopedic surgeons, and anesthesiologists implant drug infusion systems. The procedure usually takes 1 to 2 hours and can be performed under general or local anesthesia. The pump is placed in a subcutaneous pocket near the abdomen. The surgeon then inserts the catheter into the intrathecal space of the spine, tunnels it under the skin, and connects it to the pump. Surgical complications are possible and include infection, meningitis, spinal fluid leak, paralysis, and headache. While the surgical team will perform the implant, the managing center plays many roles in preparing for the pump implant, so coordination between managing and surgical teams is important.
After the infusion pump system has been implanted, patients return to the managing physician’s office to have the dose titrated until the desired therapeutic effect is reached. The managing center monitors the response to the medication and adjusts the dose over a period of weeks or months. During this time, the patient is also weaned from oral antispasticity medications, if not done prior to implant. This should be done slowly and with careful monitoring by the physician. Decisions are also made about the types of rehabilitation therapies that may be appropriate, and referrals are made as necessary.
Follow-up visits include ongoing spasticity assessment and evaluation, pump refills, programming checks, and dose adjustments. If spasticity increases after being better controlled with ITB Therapy, the managing clinician will perform a series of tests to help determine if the return of symptoms is due to a change in the patient's health or system related. Managing centers are prepared to solve problems that may occur while a patient is receiving ITB Therapy, and specific procedures have been developed to help them minimize potential emergency situations.
The section on ITB Therapy provides an overview of ITB Therapy management including severe spasticity, Lioresal® Intrathecal (baclofen injection), patient selection and management, and potential adverse effects.
ITB Therapy (Intrathecal Baclofen Therapy) is indicated for use in the management of severe spasticity. Patients should first respond to a screening dose of intrathecal baclofen prior to consideration for long term infusion via an implantable pump. For spasticity of spinal cord origin, ITB Therapy via an implantable infusion system should be reserved for patients unresponsive to oral baclofen or those who experience intolerable CNS side effects at effective doses. Patients with spasticity due to traumatic brain injury should wait at least one year after the injury before consideration of long term intrathecal baclofen therapy.
Important Safety Information for ITB Therapy: Intrathecal Baclofen Withdrawal: Abrupt discontinuation of intrathecal baclofen, regardless of the cause, has resulted in sequelae that include high fever, altered mental status, exaggerated rebound spasticity, and muscle rigidity, that in rare cases has advanced to rhabdomyolysis, multiple organ-system failure, and death.
Prevention of abrupt discontinuation of intrathecal baclofen requires careful attention to programming and monitoring of the infusion system, refill scheduling and procedures, and pump alarms. Patients and caregivers should be advised of the importance of keeping scheduled refill visits and should be educated on the early symptoms of baclofen withdrawal. Special attention should be given to patients at risk (e.g., spinal cord injuries at T-6 or above, communication difficulties, history of withdrawal symptoms from oral or intrathecal baclofen). Consult the technical manual of the implantable infusion system for additional postimplant clinician and patient information.
This therapy is contraindicated in patients who are hypersensitive to baclofen. Implantation of the infusion system is contraindicated if the patient is of insufficient body size, requires a pump implant deeper than 2.5 cm, or, in the presence of spinal anomalies or active infection.
The most frequent drug adverse events vary by indication but include: hypotonia (34.7%), somnolence (20.9%), headache (10.7%), convulsion (10.0%), dizziness (8.0%), urinary retention (8.0%), nausea (7.3%), and paresthesia (6.7%). Pump system component failures leading to pump stall, or dosing/programming errors may result in clinically significant overdose or underdose. Acute massive overdose may result in coma and may be life threatening.
The most frequent and serious adverse events related to device and implant procedures are catheter dislodgement from the intrathecal space, catheter break/cut, and implant site infection including meningitis. Electromagnetic interference (EMI) and Magnetic resonance imaging (MRI) may cause patient injury, system damage, operational changes to the pump, and changes in flow rate.
Please refer to the full prescribing information and system information for details or call Medtronic at (800) 328-0810.
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