Inclusion Criteria:  Patients with intracranial stenosis which was defined as stenosis of 50% or more in Intracranial segment of internal carotid artery and middle cerebral artery (MCA). The degree of stenosis was measured by transcranial doppler, computed magnetic resonance angiography (MRA),tomography angiography (CTA) and digital subtraction angiography (DSA).  Exclusion Criteria:  History of stroke,transient ischemic attack,seizures or unexplained loss of consciousness. Organic brain defects on T1 or T2 images. Any history or clinical signs of other severe psychiatric illnesses (like major depression,psychosis or obsessive compulsive disorder). Implanted pacemaker,medication pump,vagal stimulator,deep brain stimulator. History of substance abuse within the last 6 months.