[1] Nippon Med Sch, Dept Internal Med, Div Neurol, Tokyo 113, Japan
[2] Nippon Med Sch, Dept Internal Med, Div Nephrol, Tokyo 113, Japan
[3] Nippon Med Sch, Dept Internal Med, Div Rheumatol, Tokyo 113, Japan
[4] Stanford Univ, Dept Neurosurg, Dept Neurol & Neurol Sci, Sch Med, Stanford, CA 94305 USA
[5] Stanford Univ, Sch Med, Program Neurosci, Stanford, CA 94305 USA