Constraint-induced movement therapy

Constraint-induced movement therapy (CI or CIMT) is a form of rehabilitation therapy that improves upper extremity function in stroke and other central nervous system damage victims by increasing the use of their affected upper limb.^[1]

Types of constraint

The focus of CIMT is to combine restraint of the unaffected limb and intensive use of the affected limb. Types of restraints include a sling or triangular bandage, a splint, a sling combined with a resting hand splint, a half glove, and a mitt.^[2] Determination of the type of restraint used for therapy depends on the required level of safety vs. intensity of therapy. Some restraints restrict the wearer from using their hand and wrist, though allow use of their non-involved upper extremity for protection by extension of their arm in case of loss of balance or falls.^[3] However, restraints that allow some use of the non-involved extremity will result in less intensive practice because the non-involved arm can still be used in complete tasks.^[4] Constraint typically consists of placing a mitt on the unaffected hand or a sling or splint on the unaffected arm, forcing the use of the affected limb with the goal of promoting purposeful movements when performing functional tasks. The use of the affected limb is called shaping.^[5] Typically, CIMT involves restraining the unaffected arm in patients with hemiparetic stroke or hemiparetic cerebral palsy (HCP) for 90% of waking hours while engaging the affected limb in a range of everyday activities^[5][6] However, studies have varied on hours of restraint per day and length of therapy. More specifically, CIMT involves the person performing supervised structured tasks with the affected limb 6 hours a day for 10 days over a 14-day period, in addition to wearing the restrictive mitt or sling for 90% of waking hours.^[7] One form of modified constraint induced movement therapy that has been found to be effective in improving motor control strategy during goal-directed reaching involved massed practice of the affected limb 2 hours a day for 10 days, in addition to wearing the restrictive mitt or sling for 6 hours a day for 2–3 weeks.^[8] Practitioners say that stroke victims disabled for many years have recovered the use of their limbs using CIMT. However, it has been shown that receiving CIMT early on (3–9 months post-stroke) will result in greater functional gains than receiving delayed treatment (15–21 months post-stroke).^[9] Through research, two key factors of CIMT have emerged that relate to the effectiveness of regaining function. First is that CIMT needs to include concentrated and repetitive practice of the affected limb. Second, the other arm or hand needs to be constrained at least 90 percent of waking hours.^[10]

Mechanism of change

CIMT was developed by Edward Taub of the University of Alabama at Birmingham. Taub argues that, after a stroke, the patient stops using the affected limb because they are discouraged by the difficulty.^[4] As a result, a process that Taub calls "learned non-use" sets in, furthering the deterioration. Learned non-use is a type of negative feedback. Individuals are unable to move their affected limb or the movements are inefficient and clumsy and in response to this a suppression of movement occurs. It is this process that CIMT seeks to reverse.The American Stroke Association has written that Taub's therapy is "at the forefront of a revolution" in what is regarded possible in terms of recovery for stroke survivors.^[1]

As a result of the patient engaging in repetitive exercises with the affected limb, the brain grows new neural pathways. This change in the brain is referred to as cortical reorganization or neuroplasticity. One study by Deluca et al. showed that using Transcranial Magnetic Stimulation (TMS) that the excitable cortex of the affected cortex in adults patients with HCP doubled in size after 12 days of therapy.^[5] Recently, the possible benefits of cortical reorganization has led to studies of CIMT on children because neuroplasticity is even greater among children than adults.^[11] Particular interest is growing in CIMT for children who have cerebral palsy where one arm is more affected than the other.^[12]

Application of constraint-induced movement therapy

CIMT may be applicable to up to 75 percent of stroke patients, although the amount of improvement produced by CIMT appears to diminish as the initial motor ability of the patient decreases.^[7] CIMT has been shown to be an effective means of stroke rehabilitation regardless of the level of initial motor ability, amount of chronicity, amount of prior therapy, side of hemiparesis, or infarct location.^[13][14][15] This suggests that CIMT-induced plasticity may work irrespective of the pathways in the damaged motor network.^[14] Although, due to the intensity of this treatment, patients who have suffered profound upper extremity paralysis from their condition are normally not eligible for constraint-induced upper extremity training.^{[13][15][16][17]} A consistent exclusion criterion for CIMT has been the inability to perform voluntary wrist and finger extension in the involved hand.^{[13][15][16][17]}

CIAT (Constraint Induced Aphasia Therapy) is an adaptation of CIMT for people with Aphasia. It can be used for clients with either expressive or receptive aphasia. Like CIMT, treatment is intensive and usually occurs over a ten-day period for several hours per day. In CIAT, patient must use verbal communication without gestures or pointing in order communicate. The constraints are placed on the use of gestures with the aim of improving verbal communication.

Constraint-induced movement therapy (CIMT) coupled with intensive and varied exercise training has proven to be effective in reducing spasticity and increasing function of the hemiplegic upper extremity in chronic stroke patients.^[18] Siebers, Oberg and Skargren conducted a study in 2010 involving patients between 6 months to 10 years post stroke. The unaffected upper limb of each subject was constrained using a restricting position belt for 90% of waking hours, 7 days a week, for 2 weeks and they were each assigned individualized, upper extremity exercise programs by a physiotherapist and occupational therapist to be completed 5 days a week in an outpatient rehabilitation clinic. Reduced spasticity and improved function were measured following the 2-week treatment block and improvements persisted 6 months later.^[18] Therefore, chronic hemiplegia can significantly benefit from CIMT with reductions in disuse complications, spasticity and improved function with increased use of the hemiplegic limb in activities of daily life.^[18]

The effects of constraint-induced movement therapy have been found to improve movements that not only remain stable for months after the completion of therapy, but translate well to improvements of everyday functional task.^[19] This can be done by including the “transfer package” of CIMT during treatment, in which the physiotherapist applies various strategies to help the patient adhere to the requirements of CIMT outside the clinical setting.^[20] These strategies may include: 1. Monitoring, which requires patients to document their performance of target behaviours; 2. Problem solving, in which patients create solutions and identify outcomes to potential obstacles; and 3. Behavioural contracting, which involves getting patients to identify the components and methods of carrying out normal behaviors.^[20] Gauthier and colleagues demonstrated the importance of the “transfer package” by comparing outcome measure scores of post-stroke patients who participated in CIMT with and without the “transfer package”.^[21] Those whose treatment included the “transfer package” had a significantly higher score in the Quality of Movement scale of the Motor Activity Log than those whose treatment did not include the “transfer package”, indicating that the former group used their affected arm more in real life situations.^[21]

Limitations to implementation

Presently, constraint-induced movement therapy (CIMT) has not been incorporated as part of standard practice for the rehabilitation of the hemiplegic upper extremity.^[22] Concerns have been raised over the generalizability of the results obtained from research, as selection criteria for CIMT research has excluded patients with a moderate or more severe stroke, due to balance problems, serious cognitive deficits, and global aphasia, which may reduce understanding of safety instructions and interfere with a patient’s ability to communicate difficulties.^[23]

The cost of resources needed to conduct CIMT treatment protocol are high. Costs are generated due to the intensity of therapy required for CIMT, as participants typically receive up to 6 hours of one-on-one therapy at least 5 days per week for 2 weeks.^[23] CIMT can be prohibitively expensive for patients paying out-of-pocket or for publicly funded health care systems attempting to make this program available to all eligible stroke survivors.^[22]

Therapist apprehension directed at safety issues with constraint use, lack of facilities, the cost of providing one-on-one therapy sessions, and the opportunity costs associated with the therapist’s inability to see and treat other patients during that time has contributed to the resistance of adopting the CIMT protocol.^[22][23]

The patient’s ability to tolerate the intensity and duration of the therapy sessions is a limiting factor to protocol adoption. Stroke patients have commonly expressed the length of time wearing the constraint and time consuming hours of therapy as reasons they wish not to participate.^[23]

While the CIMT protocol results in improved function in its target population, it is unknown whether the combination of constraint and therapy is necessary to achieve the outcome seen or whether the benefit is due to exposure to high-intensity, task-specific activities focused on the use of the more affected limb.^[22][23]

See also

• Neuroplasticity
• Recovery Rapids
• Silver Spring Monkeys

References