The Occupational Therapy team at The Huntercombe Group's specialist Brain Injury Rehabilitation Centre at Frenchay (Bristol), are exploring the use of mirror therapy to aid motor recovery in patients with acquired brain injury who are suffering from hemi-paresis (loss of control and weakness). Upper Limb Hemi-paresis is common in patients following an acquired brain injury often impacting on the individual's ability to use the limb functionally.
A trial use of mirror therapy, with a 20 year old man who had sustained a traumatic brain injury, demonstrated an improvement in distal upper limb function. The Chedoke arm and hand inventory was used as an outcome measure, and results showed a reduction in the level of assistance required. The subject also demonstrated an increase in the spontaneous use of his affected upper limb during assessment which has enabled him to participate in further treatment options. Other benefits experienced included an increase in 'ownership' and reduction in the neglect of the affected upper limb. Two years on, the patient continues to use mirror therapy and commented "it still gives me movement and flexibility, whereas, if my arm is left to its own devices, it tightens up".
The team assisted the patient to use the therapy for 20-30 minutes a day for five days a week for up to six weeks. The outcome has encouraged the clinical team to explore the use of this approach in other patients with an acquired brain injury.
Donna Wilding, Lead Occupational Therapist, at The Frenchay Brain Injury Rehabilitation Centre said: "In the stroke population, evidence suggests that Mirror Therapy is especially beneficial for those without detectable motor function of the distal upper limb. However, to date, there is little evidence for its use within the acquired brain injury population, due to the global cognitive and perceptual impairments that our patient group often present with, exclude them from research studies. We therefore set out to explore whether the therapy would be suitable for our patients who may experience cognitive impairments, for example, attention deficits or communication difficulties. The initial outcome is very encouraging, leading us to extend our studies to other patients who might potentially benefit."
Mirror therapy stems from studies in the 1990's by Ramachandran, of phantom limb pain (PLP). Ramachandran suggested that phantom limb pain may be due to changes in the brain rather than peripheral nerves. He created the mirror box and noticed remarkable changes in amputees with PLP. In 1994 Ramachandran suggested that visual feedback may also help recovery of arm and leg function post stroke. It is related to motor imagery, bilateral upper limb training and movement observation.
Mirror therapy creates an illusion that the patient is once again able to use the extremity, giving positive feedback and reward. The patient sits at a table and the mirror is placed in the saggital plane (a vertical plane which passes from front of the person to rear, effectively dividing the body into right and left halves.) The hemiplegic arm is placed out of view. The reflective part of the mirror shows the non-affected arm. The patient is asked to perform exercises with both extremities focusing on the reflection of their non-affected arm. The patient views the reflection as if it were the hemiplegic side.
Motor imagery and movement execution are driven by the same mechanisms linked into the Pre-Motor Cortex and Motor Cortex that plan and drive movements
Credit: The Huntercombe Group's Frenchay hospital