▁people ▁with ▁T ou ret te ▁synd rome ▁and ▁related ▁t ic ▁dis orders ▁make ▁invol unt ary ▁movements ▁and ▁utter ances ▁( called ▁t ics ) ▁despite ▁the ▁fact ▁that ▁they ▁would ▁prefer ▁not ▁to ▁do ▁so ▁when ▁it ▁is ▁soci ally ▁in app ropri ate . ▁T ics ▁are ▁described ▁as ▁semi - vol unt ary ▁or ▁un vol unt ary , ▁because ▁they ▁are ▁not ▁strictly ▁invol unt ary : ▁they ▁may ▁be ▁experienced ▁as ▁a ▁volunt ary ▁response ▁to ▁an ▁unw anted , ▁pre mon itory ▁ur ge . ▁T ics ▁are ▁experienced ▁as ▁ir res ist ible ▁and ▁must ▁eventually ▁be ▁expressed . ▁People ▁with ▁T ou ret te ▁synd rome ▁are ▁sometimes ▁able ▁to ▁suppress ▁their ▁t ics ▁for ▁limited ▁periods , ▁but ▁doing ▁so ▁often ▁results ▁in ▁an ▁explos ion ▁of ▁t ics ▁after ward . ▁The ▁control ▁ex ert ed ▁( from ▁seconds ▁to ▁hours ▁at ▁a ▁time ) ▁may ▁merely ▁post p one ▁and ▁ex ac erb ate ▁the ▁ult imate ▁expression ▁of ▁the ▁t ic . ▁ ▁In ▁al ien ▁hand ▁synd rome , ▁the ▁aff lic ted ▁individual ' s ▁lim b ▁will ▁produce ▁un intent ional ▁movements ▁without ▁the ▁will ▁of ▁the ▁person . ▁The ▁affected ▁lim b ▁effectively ▁demonstr ates ▁' a ▁will ▁of ▁its ▁own .' ▁The ▁sense ▁of ▁ag ency ▁does ▁not ▁emer ge ▁in ▁conj unction ▁with ▁the ▁over t ▁appearance ▁of ▁the ▁purpose ful ▁act ▁even ▁though ▁the ▁sense ▁of ▁ownership ▁in ▁relationship ▁to ▁the ▁body