Comparison of Goal-specific Functional Task With and Without Mirror Therapy on Upper Limb Function of Post-stroke Patients.

The hemi paretic arm is one of the most undesirable consequences of stroke. Approximately 30-66% of patients with stroke are not able to gain motor function of their affected hand which prevents them from performing their daily activities for the rest of their lives.The paralysis of upper limb along with increase in muscle spasticity, muscle weakness and loss of sensory perception are reasons of disability in stroke patients. It is very important in the treatment of stroke patients to make effective treatment strategies to improve their upper limb function. Many treatment options are used for the recovery of upper limb motor function such as robot-assisted therapy and constraint induced movement therapy. Mirror therapy has drawn much focus for the rehabilitation of hemiplegic stroke patients in the past two decades. Mirror therapy is one of the priming technique that causes neural plasticity of brain.Mirror therapy is also used to address problems like phantom limb pain.In stroke patients it is helpful in managing pain and hemi spatial neglect. According to the theory the cortical areas of brain that are involved in the motor task execution can be activated by observing the actions performed by others, which is the function of the mirror neuron system (MNS).The mirror neuron system is composed of mirror neurons that discharge during action observation (AO) and action execution. The mirror neuron system is located in the inferior frontal gyrus (IFG), including the ventral premotor cortex (PMv), the inferior parietal lobule (IPL), and the intraparietal sulcus (IPS). It also extends to other brain areas like the primary motor cortex, the primary somatosensory cortex, and the middle frontal cortex. In mirror therapy we use the mirror neuron system to perform action observation training (AOT) and action execution.

In mirror therapy a mirror is placed in the mid sagittal plane of a patient between the two arms and the patient is given instruction to move his less affected or normal limb while looking at its reflection in the mirror which will produce as the affected or paretic limb is also moving with a normal movement pattern.This will create visual stimulus on the patient's brain known as mirror visual feedback (MVF) and will cause cortical reorganization hence it will increase the motor recovery of the affected or paretic limb.

The scales that have been used in previous studies to measure motor recovery and improvement in daily functions of stroke patients with mirror therapy are Brunnstrom stages of recovery, Fugl-Meyer assessment (FMA) and Functional Independence Measure (FIM).The findings of these studies has shown positive effects of mirror therapy on decreasing motor impairment.

Conventional mirror therapy that is most commonly used involves simple movements performed by unaffected arm like wrist extension flexion, fingers flexion extension and forearm supination and pronation while looking at the visual stimulus created by the mirror placed at their mid sagittal plane.

The functional task-oriented training is mostly used intervention for bringing beneficial neural plasticity and improving paretic upper limb functional performance. Functional task-oriented training recently applied on stroke patients has proven to be more effective than the conventional therapy. A type of mirror therapy is task based mirror therapy in which the participants are asked to perform specific motor tasks with their less affected arm. Functional tasks may include flipping a card, holding a polystyrene cup, squeezing a sponge. A research was carried out in Korea to determine the effects of mirror therapy with functional tasks on upper limb function and activities of daily living in patients with subacute stroke. The patients were randomly divided into two groups the mirror therapy group and the control group.The Fugl-Meyer Motor Function Assessment (FMA), Brunnstrom motor recovery stage, and Modified Barthel Index (MBI) were assessed 4 weeks after the treatment and the results were significantly greater in the mirror therapy group than the control group.