1Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea. ciyoo62@hanmail.net
2Department of Neurology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
3Department of Internal medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea. JFIF d d Ducky d qhttp://ns.adobe.com/xap/1.0/