[1] Reg Med Ctr, Dept Neurol CH49, Seattle, WA 98105 USA
[2] Univ Washington, Sch Med, Dept Neurol, Seattle, WA 98195 USA
[3] Univ Washington, Sch Med, Dept Pathol Neuropathol, Seattle, WA 98195 USA
[4] Univ Washington, Sch Med, Dept Pediat, Seattle, WA 98195 USA