cular ▁j unction ▁( the ▁connection ▁between ▁n erves ▁and ▁the ▁mus cle ▁that ▁they ▁supply ). ▁The ▁diagn osis ▁is ▁usually ▁confirmed ▁with ▁elect rom y ography ▁and ▁blood ▁tests ; ▁these ▁also ▁distinguish ▁it ▁from ▁my as then ia ▁gra vis , ▁a ▁related ▁auto imm une ▁neur om us cular ▁disease . ▁ ▁If ▁the ▁disease ▁is ▁associated ▁with ▁cancer , ▁direct ▁treatment ▁of ▁the ▁cancer ▁often ▁rel ieves ▁the ▁sympt oms ▁of ▁LE MS . ▁Other ▁treat ments ▁often ▁used ▁are ▁ster oid s , ▁az ath iop r ine , ▁which ▁suppress ▁the ▁imm une ▁system , ▁int ra ven ous ▁imm un og lob ul in , ▁which ▁out comp etes ▁aut ore active ▁ant ib ody ▁for ▁F c ▁re cept ors , ▁and ▁py rid ost ig mine ▁and ▁ 3 , 4 - d iam in opy rid ine , ▁which ▁enh ance ▁the ▁neur om us cular ▁transmission . ▁Occ asion ally , ▁pl asma ▁exchange ▁is ▁required ▁to ▁remove ▁the ▁ant ib od ies . ▁ ▁The ▁condition ▁affect s ▁about ▁ 3 . 4 ▁per ▁million ▁people . ▁LE MS ▁usually ▁occurs ▁in ▁people ▁over ▁ 4 0 ▁years ▁of ▁age , ▁but ▁may ▁occur ▁at ▁any ▁age . ▁ ▁Sign s ▁and ▁sympt oms ▁The ▁weak ness ▁from ▁LE MS ▁typically ▁involves ▁the ▁mus cles ▁of ▁the ▁proxim al ▁arms ▁and ▁legs ▁( the ▁mus cles ▁closer ▁to ▁the ▁tr unk ). ▁In ▁contrast ▁to ▁my as then ia ▁gra