Strength in SISTERS (Spasticity in Stroke–Randomised Study)

New study shows effectiveness of ITB vs. oral medications in reducing post-stroke spasticity

Considering the myriad complications and health effects an individual can endure following stroke, spasticity—the involuntary contraction of muscles when attempting to use an affected limb—may not seem like a primary concern. But left untreated, spasticity can deter the patient’s rehabilitation efforts as they apply to regaining use of those affected limbs.

When a muscle is unable to complete a full range of motion, tendons tighten, making stretching extremely challenging and in some cases, leading to the “freezing” said muscle into a permanent, sometimes painful position. Quality-of-life outcomes are obviously adversely affected in such scenarios, and given that some 43 percent of patients encounter spasticity in the first year following a stroke, this is not a condition to be taken lightly.

Until recently, oral medications were believed to be the gold standard for treatment of post-stroke spasticity (PSS) in adults. But data from the ‘Spasticity in Stroke–Randomised Study” (SISTERS) trial recently published in the Journal of Neurology, Neurosurgery & Psychiatry (JNNP) holds new hopes for those suffering from particularly acute cases of PSS.

SISTERS results demonstrated the ability of Intrathecal Baclofen Therapy (ITB), and particularly its superiority to oral medication, in reducing spasticity in patients following stroke.

Michael J. Creamer, DO, medical director of Park Place Surgery Center and a member of Central Florida Pain Relief Centers in Orlando, FL, served as lead author and investigator for the SISTERS study. Dr. Creamer presented the findings of the SISTERS study at last month’s North American Neuromodulation Society (NANS) Annual Meeting in Las Vegas. He explained the impact of the SISTERS study to ADVANCE.

“Individuals who’ve had a stroke and present with spastic hemiplegia are one of our more challenging patient populations,” Dr. Creamer revealed. “The condition results in spasticity, and increased muscle tone, typically on one side of the body.”

Until recently, management involved oral antispasmodics – as well as physical therapy and occupational therapy – as primary treatment, along with splinting and electrical therapy as complements. “But those therapies tend to be inadequate, especially in those with severe spasticity,” said Dr. Creamer. “In a large percentage of patients, spasticity continues to interfere with their quality of life and ability to function.”

Additionally, caretakers can find it extremely challenging to meet the needs of these individuals. Socially, affected patients often feel uncomfortable or embarrassed when leaving their homes. “That’s what prompted the initiation of this study,” said Dr. Creamer.

Bu using an intrathecal pump to deliver Baclofen, investigators hoped to demonstrate greater spasticity control than conventional medical management. Dr. Creamer and his team accomplished this by using Medtronic’s SynchroMed II Infusion System – the only U.S.-approved system for delivering ITB therapy.

SISTERS focused on individuals who’d sustained a stroke and presented with residual severe spastic hemiplegia affecting both the upper and lower extremities, and who’d not met their goals through conventional treatment interventions.

“Oral medications are typically inadequate, and fraught with side effects of sedation,” explained Dr. Creamer. “Individuals who’ve had strokes—what some people would term a “brain attack”—they’re already susceptible to potential cognitive impairment. Introducing medications that may lead to further cognitive impairment—making them sleepy, reducing attention span—can place significant limitations on our ability to help their function improve.”

Also, as Dr. Creamer alluded, the medications are commonly inadequate. Even without considering the side effects, medications don’t typically produce the desired outcomes for patients.


The SISTERS study randomized 60 patients, with 25 individuals receiving a Baclofen pump implant. Over a period of several years, a total of 48 (80 percent) patients completed the full six-month study—24 who had the pump implanted, and 24 involved in conventional medical management. Primary analysis (with specific results available in the above-linked study) showed a significant improvement for those treated via ITB when compared to the group treated via conventional medical management.

Ultimately, as Dr. Creamer wrote, “these data support the use of ITB therapy as an alternative to conventional medical management for treatment of generalized PSS in adults.”

“One advantage is ITB provides a continuous infusion of medications to reduce spasticity, and reduce tone,” said Dr. Creamer. “Statistically, the reductions were incredibly significant in the individuals who had the pumps implanted in the upper and lower limbs—that’s a very important point. The consistent delivery of medication allowed for constant reduction of tone.”

The medication intervals with oral antispasmodics can lead to issues such as dose fluctuations. Injections with a three-month interval also have a tendency to be observed with fluctuation of tone, not to mention issues with patient compliance. Implementation of the ITB pump has the potential to offer more consistent, long-term improvement in individuals.

“We did demonstrate a reduction of pain—what we considered “least pain” and “actual pain,” said Dr. Creamer. (“Worst pain” was also improved, but not to a statistically significant degree.)

Functional outcomes demonstrated an improvement in ITB groups as well, despite the lack of statistical significance. “The study was relatively short, lasting only six months,” explained Dr. Creamer, “so we would anticipate further, long-term benefits of spasticity management over the lifetime of an individual.”

Dr. Creamer expressed the dramatic level of improvement through the story of a gentleman, who had not walked in over two years, coming to him complaining of shoulder pain. Upon realization that this individual had suffered a stroke, an ITB pump was implanted.

After the pump was implanted, tone reduced, mobility improved—and the patient was able to ambulate.

“Unbelievable!” exclaimed Dr. Creamer. “You never expect to see such a thing, that after two years, the decrease in tone would lead to the ability to ambulate once again.”

“Typically, these are patients who people have given up on them. The individuals say “there’s nothing more that can be done.” The doctors say “we tried the pills; they didn’t work.”

“This is an opportunity to demonstrate significant reduction in tone pain, improvement in function—we’ve shown that there are options to help improve their quality of life.”

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