A 63-year-old woman presented with swelling and reduced range of movements in the right upper limb following a fracture of scaphoid bone. She was diagnosed with complex regional pain syndrome (CRPS I). Simple analgesics and neuropathic medications were of no benefit, and sympathetic blocks were equally ineffective.
Following a study course at the International Association for the Study of Pain conference in Sydney, Australia, in 2005, she was commenced on mirror box therapy (Fig. 4), first described by Ramachandran in the treatment of phantom limb pain . The patient had an immediate and dramatic improvement in the movement of the affected limb and reduction in pain scores of more than 50%. Following this trial in the outpatient department, she was then issued with a mirror box to take home.
Ramachandran proposed in patients with phantom limb pain that there is disruption in the normal interaction between motor intention to move a limb and proprioceptive feedback. They speculated that visual feedback might interrupt this pathological cycle. Mirror box therapy for CRPS is thought to work by providing such a visual feedback: by moving the unaffected limb in front of the mirror there is cortical reorganisation of the sensory homunculus within the parietal cortex. Whether these changes in the cortex are a primary or secondary effect of CRPS is still unknown. Mirror box therapy may provide a quick, cheap, effective and relatively painless form of management for a condition that is very resistant to conventional therapeutic strategies.