Apreviouslyhealthy16-year-oldgirldevelopednumbnessandtinglinginthelowerextremitiesthatprogressedovera10-weekperiodtotheupperlimbs.Twoweekspriortoadmission,shealsodevelopedweaknessinherarmsandlegs,tothepointofneedinghelpgettingdressedandsupportforwalking.Shedeniedsphincterorsystemicsymptoms.Duringthepreviousyear,shehad