Examination of two novel therapies for enhancing motor ability in chronic stroke patients using behavioural measurements and transcranial magnetic stimulation

Rehabilitation techniques are currently the major therapeutic approach for helping stroke patients recover from hemiparesis, yet the neurophysiological mechanisms underlying their effectiveness are poorly understood. In the present investigation, chronic stroke patients were chosen at least one year after stroke and received either Mirror Therapy (Altschuler et al., 1999) or Constraint-Induced (CI) Movement Therapy (Taub et al., 1993). Motor improvements were examined in parallel with transcranial magnetic stimulation (TMS) and electromyography (EMG). TMS was combined with EMG to record recruitment curves and silent periods induced by direct stimulation of the motor cortex before and after treatment. The data revealed that motor ability gained with CI Therapy was particularly impressive, and that neurophysiological patterns of recovery may differ with respect to pathology. Data obtained in two patients with capsular lesions acquired in adulthood suggest the involvement of ipsilateral pathways in recovery mechanisms. By contrast, data from a patient with perinatal lesions in the thalamus and the red nucleus area suggest involvement of contralateral pathways in recovery mechanisms.