1. Department of Physical Therapy, Chang Gung University, 259 Wen-Hwa 1st Rd, 333, Kweishan, Taoyuan, Taiwan, R.O.C. Tel.: ; Fax: ; E-mail: linyh@mail.cgu.edu.tw
2. Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA and the Raymond Jordon Center for Balance Disorders