Sep. 18, 2010
Earlier is Better in Constraint-Induced Movement Therapy for Stroke
When patients are receiving constraint-induced movement therapy for stroke, earlier is better, but those that delay therapy can still catch up, according to a comparison of two groups of patients published online in the journal Stroke.
Constraint-induced movement therapy (CIMT) involves restricting use of the less-impaired hand with a padded mitt for up to six hours a day, coupled with training in tasks such as opening a door, dressing, or eating and drinking. The study enrolled 222 stroke patients who retained some ability to extend their arms and open their hands on the affected side.
The paper compared study participants who began a two-week course of CIMT three to nine months after their strokes to those who began therapy 15 to 21 months after stroke. The group that began CIMT sooner after their strokes saw greater improvement after a year, but the two groups were comparable after 24 months.
“If you delay therapy, you can get to the same place as the early therapy group, but it takes longer. The rate of improvement isn’t as fast,” says Steven Wolf, PhD, PT, FAPTA, professor of rehabilitation medicine at Emory University School of Medicine and principal investigator for the study.
Other universities involved in the EXCITE (Extremity Constraint Induced Therapy Evaluation) study were the University of Alabama at Birmingham (training center), Washington University at St. Louis (data management), University of Florida, Ohio State University, University of Southern California, University of North Carolina at Chapel Hill and Wake Forest University.
Participants were evaluated using the Wolf Motor Function Test, a measure of time needed to complete a task, as well as a Motor Activity Log tracking how well and how often 30 common daily activities were performed.
After two weeks of CIMT, early participants had their Motor Activity Log “amount of use” scores increase from 1.13 to 2.29, and end up at 2.17 a year later. Delayed participants had their scores increase from 1.79 to 2.45 after therapy and end up at 2.15.
Until EXCITE, research into CIMT for stroke rehabilitation had focused mostly on patients who had experienced a stroke more than a year ago.
“Our results illustrate the brain’s capacity to rewire itself,” Wolf says. “Even as fewer resources are available to address catastrophic injuries such as stroke, it’s important to know this group of patients still has a capacity to improve their ability to perform important functions when given the chance.”
The initial results of the EXCITE study were published in JAMA in 2006, and the trial was conducted in a crossover model. This means that study participants who acted as initial control subjects received CIMT after one year. Participants who delayed CIMT had other forms of treatment, such as massage, acupuncture or strength training while waiting — a potential complicating factor.
“We learned that it doesn’t matter what kind of treatment you get in the year before CIMT starts, because all the patients can respond to constraint therapy once it starts,” Wolf says.
He notes that the EXCITE study included patients who retained some ability to move the stricken arm and hand – a group that is estimated to comprise somewhere between 5 and 25 percent of all stroke patients. About 85 percent of stroke survivors experience partial paralysis on one side of the body. Whether the stroke affected the patient’s dominant hand, and whether the patient was right or left handed, was not statistically significant.
The EXCITE study was supported by the National Institute of Child Health and Human Development and the National Institute of Neurological Diseases and Stroke.
Wolf SL et al. "The EXCITE Stroke Trial. Comparing Early and Delayed Constrain-Induced Movement Therapy." Stroke early online publication (2010)
Wolf SL and EXCITE Investigators. Effect of constraint-induced movement therapy on upper extremity function 3 to 9 months after stroke: the EXCITE randomized clinical trial. JAMA. 296:2095-104 (2006).
Wolf SL, Winstein C, Miller JP, Thompson P, Taub E, Uswatte G, Morris D, Blanton S, Clark PC Retention of upper limb function in stroke survivors who have received constraint-induced movement therapy: the EXCITE randomised trial. The Lancet Neurology. 7:33-40 (2008).
Writer: Quinn Eastman
The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service.