[1] Jikei Univ, Sch Med, Dept Rehabil Med, Minato Ku, Tokyo 1058461, Japan
[2] Shimizu Hosp, Kurayoshi, Tottori 6820881, Japan
[3] Tokyo Gen Hosp, Dept Neurosurg, Nakano Ku, Tokyo 1658906, Japan
[4] Nishi Hiroshima Rehabil Hosp, Saeki Ku, Hiroshima 7315143, Japan
[5] Tokyo Gen Hosp, Dept Rehabil Med, Nakano Ku, Tokyo 1658906, Japan
[6] Jikei Univ, Sch Med, Div Mol Epidemiol, Minato Ku, Tokyo 1058461, Japan