Stroke arises from an acute interruption of blood (oxygen and glucose) supply to the brain tissue. A new and possibly more descriptive term for stroke which has a similar meaning and emphasis as heart attack is “brain attack”, indeed some hospitals are now organising “brain attack teams” to manage the immediate stroke episode in a similar fashion to the more familiar cardiac arrest and trauma teams.
By the nature of the injury and dependant upon the area of damage within the brain, stroke can cause a variety of loss in the motor pathways that control movement.
Within the last few years functional magnetic resonance imaging alongside non-invasive methods of cortical stimulation have begun to reveal the importance of the functional integration of the motor and somatosensory cortex in limb movement.
The evidence for bilateral movement training especially in upper limb rehabilitation is beginning to build. It has been suggested that visualising and undertaking symmetrical bilateral movements post stroke enhance neuroplastic changes within the brain. The theories suggest increased disinhibition of the motor cortex allowing increased use of spared pathways within the damaged hemisphere, increased activity of motor command pathways in the affected hemisphere running to the spinal nerves and increased activation of the pathways from the unaffected hemisphere to supplement the damaged crossed corticospinal pathways.
The role of mirror box / visual therapy in this bilateral movement training is central to its success.