Results of a study published in the September issue of Stroke: Journal of the American Heart Association show that the tight, stiff muscles experienced commonly by stroke survivors can be improved significantly with a treatment that uses an implantable drug pump to deliver medication directly into the fluid surrounding the spinal cord.
The article reports that continuous infusion of the drug baclofen into the intrathecal space –– a treatment from Medtronic, Inc. (NYSE: MDT), called Intrathecal Baclofen (ITB™) Therapy –– can maintain a significant reduction in severe spasticity and other forms of spastic hypertonia associated with stroke.
“This reduction in [abnormal, excessive muscle] tone,” conclude the authors from the University of Alabama at Birmingham (UAB), “will allow more freedom of movement and the potential for improved function when combined with a [rehabilitation] therapy program after ITB pump placement.” Added UAB physiatrist Jay M. Meythaler, M.D., J.D., the study’s primary investigator: “Between 30 and 50 percent of stroke survivors develop tight, stiff muscles, and our study confirms that a subset of these patients can be treated effectively for this condition with ITB Therapy.”
According to the National Stroke Association (NSA), stroke is the third-leading cause of death and the No. 1 cause of adult disability in the United States. Of the more than 4 million American stroke survivors, the NSA estimates that two-thirds of them struggle with moderate to severe disabilities, including spasticity.
“This abnormal, excessive muscle tone can cause many problems, including pain, loss of free movement of a limb, and interference with the ability to walk and perform daily activities, such as bathing or dressing,” the authors explain. “It also may cause the limb to become ‘fixed’ or frozen in an uncomfortable position.” Of the 21 patients in the study reported in Stroke, 17 received ITB Therapy after being implanted with Medtronic’s programmable drug pump. According to three commonly used measures for evaluating stiffness, spasms and reflex, ITB Therapy resulted in significant decreases in spastic hypertonia and improved reflexes in both the upper and lower limbs.
Using the five-point Ashworth Scale, average stiffness (excessive muscle tone) in the affected leg decreased by nearly 50 percent –– from 3.7 before treatment to 1.8 after treatment –– with ITB Therapy. Similarly, ITB Therapy reduced stiffness in the affected arm from 3.2 to 1.8 on the scale.
“Unfortunately, many people don’t realize that the devastating effects of stroke can be felt long after an initial attack –– surviving is just the first hurdle,” said Patti Shwayder, executive director of the NSA. “The results of this study show that ITB Therapy is an important treatment option that can help stroke survivors suffering from spasticity regain control of their bodies.”
According to Baylor College of Medicine physiatrist Dr. Gerard E. Francisco, head of the brain injury program at The Institute for Rehabilitation and Research (TIRR) and a guest editor for the September issue of Stroke, ITB Therapy fills a “niche … for stroke survivors who have severe, functionally limiting, multijoint spastic hypertonia with predominant involvement of the lower limbs, and who cannot tolerate the effects of oral drugs or respond to adequate doses of other therapies.”
Dr. Francisco’s editorial comment concludes: “This pioneering work by Meythaler et al. confirms the efficacy of ITB [Therapy] in unilateral spastic hypertonia and how it may help unleash the potential for functional recovery after stroke.”
Adverse events in the study included urinary retention in five patients and postoperative headache with nausea in several. None were serious, and all were transient with dosage reductions or resolved with conservative treatment.
ITB Therapy for the treatment of severe spasticity of cerebral origin, including stroke, cerebral palsy and brain injury, received approval from the U.S. Food and Drug Administration in 1996. The FDA approved ITB Therapy as a treatment for severe spasticity of spinal origin, including multiple sclerosis and spinal cord injury, in 1992. More than 15,000 people worldwide have received treatment for severe spasticity with ITB Therapy.
In clinical trials, Lioresal® Intrathecal (baclofen injection: 10 mg/5 mL, 10 mg/20 mL, 0.05 mg/1 mL) was shown to reduce severe spasticity. Results vary; not every individual will receive the same benefits. Possible adverse events include: loose muscles, sleepiness, upset stomach, vomiting, headaches and dizziness. The most common device-related complications reported involve catheter kinks, dislodgements and breaks. Overdose, although rare, may lead to respiratory depression, loss of consciousness and reversible coma; in extreme cases, it may be life threatening. Almost all patients who experienced adverse events in the clinical studies continued with the therapy.
As with any surgical procedure, complications can occur. Since the pump and catheter are placed beneath the skin, infections can develop and are generally related to the healing of the surgical incision, not to long-term use of ITB Therapy.
Complete prescribing information for ITB Therapy appears in the Lioresal Intrathecal (baclofen injection) package insert. Lioresal is a registered trademark of Novartis Pharmaceuticals Corp. More information about spasticity and ITB Therapy is available online at www.spasticity.com and www.medtronic.com/neuro/itb, and by calling 1-866-9-STROKE.
Medtronic (www.medtronic.com), headquartered in Minneapolis, is the world’s leading medical technology company, providing lifelong solutions for people with chronic disease.
