Stem cell theray in old stroke patients is a study to treat stroke patients approved before in our hospital. We recruit these patients who received stem cell therapy and completed the study. We adopted movement-related cortical potential,and cortico-cortical inhibition to assess the stroke patients with or without stem cell therapy. Further analyzing the correlation of the motor related cortical potential and cortico-cortical inhibition among them. We wanted to find out if there are changes in cortical excitability in subjects with chronic stroke after stem cell therapy.

Inclusion Criteria:

• 1.old cerebral infarction (middle cerebral artery territory as documented on the T2 weight image [T2WI] of MRI) 2.between 6 months and 5 years of onset 3.National Institute of Health stroke scale (NIHSS) of between 9 and 20.

Exclusion Criteria:

• 1.Seizure history 2. Pacemaker insertion

36 patients suffered from old cerebral infarction (middle cerebral artery territory as documented on the T2 weight image [T2WI] of MRI) between 6 months and 5 years of onset who had initial scores on the National Institute of Health stroke scale (NIHSS) of between 9 and 20.