Research into constraint-induced movement therapy

Sep 8 2004

Traditional treatment of movement problems for people who have suffered traumatic brain injury or strokes has mainly focused on making the best use of motor functions the patient has retained.

A team at the University of Surrey is now examining a method which focuses on improving the weaker arm of patients with upper body hemiparesis (hand/arm disability resulting from brain damage). Professor Annette Sterr and her Clinical Neuroscience Research Group are carrying out a five-year study into the practical clinical application of constraint-induced movement therapy (CIT) and the brain mechanisms thought to make the treatment successful. The study is funded by a £760k Career Establishment Grant from the Medical Research Council.

CIT was founded in the US by Professor Edward Taub. He demonstrated that if monkeys with a disabled upper limb had their stronger arm constrained for several consecutive days whilst training their disabled limb using a behavioural learning technique called ‘shaping’, they would regain some use of the disabled limb. Professor Taub then tried this treatment with stroke patients with reduced hand function, constraining their good arms for 90% of waking hours for two weeks, whilst their affected arms were shaped for six hours a day by performing increasingly difficult arm movements. All the patients showed a marked improvement.

Such research would not be viable in rehabilitation clinics, as they are not designed to see patients for such long periods, and the longer therapy sessions may be too strenuous for many stroke victims. The study aims to build on Professor Sterr’s previous work which achieved significant results using shorter training periods and without constraining the good arm. The project also aims to understand the brain mechanisms linked to CIT success by studying brain images with fMRI and recording electrical activity in the brain with EEG. Professor Sterr says: “We know that recovery from brain damage relies on the rewiring of brain circuits and that this process can be stimulated by the tasks you give your brain to do. It is believed that intensive training helps the regain of function by engaging neurons so new brain connections can be formed. By studying electrical activity and images of the brain before and after treatment we are able to test this theory”.

The study at UniS will test 112 volunteers who have limited movement in one side of their upper body following a brain injury or stroke at least 12 months previously. Each volunteer will undergo fMRI scans and EEG recordings before and after treatment. The fMRI scanner is a research-only scanner, which allows the team to look at the functioning of the brain, in addition to brain structure shown by MRI scanners.

One group of volunteers will receive standard CIT treatment, while in a further four groups the length of training will vary, as will the use of a constraint. Training will last for two or three weeks, with follow ups every six months for two years. Once back at home, the volunteers will be given a programme of tasks to practise every day.

Group research officer Amy Saunders recently spent three weeks at the University of Alabama studying with Professor Taub, and is now looking to recruit volunteers for the UniS study. Patients need to be low functioning and the approval of their GP will be sought before they can be considered for the study.