HMPAO SPECT Study of Regional Cerebral Blood Flow in Dissociative Identity Disorder

Abstract

Abstract The aim of the study was to in ves ti gate if there were any char ac ter is tics of re gional c e re bral blood flow (rCBF) in dissociative iden tity dis or der. Fif teen pa tients with dissociative iden tity dis or der and eight healthy vol un teers par tic i pated in the study. The clin i cal di ag no sis of dissociative iden tity dis or der was con firmed us ing the Struc tured Clin i cal In ter view for DSM-IV Dissociative Dis or ders. The Struc tured Clin i cal In ter view for DSM-III-R was also ad min is tered to all pa tients in or der to screen comorbid psy chi at ric con di tions. Re gional ce re bral blood flow was stud ied us ing a SPECT sys tem with Tc99m-hexamethyl -propylenamine (HMPAO) as a tracer. The rCBF ra tio was de creased in orbito-fron tal re gion bi lat er ally and in creased in left (dom i nant hemisphere) lat eral tem po ral re gion among pa tients with dissociative iden tity dis or der when com pared to the con trol group. The struc tured in ter view di ag no ses of con cur rent or life time ma jor de pres sion, PTSD, psy chotic dis or der, or on go ing drug treat ment were not sig nif i cantly re lated to perfu sion in these re gions. There was no sta tis ti cally mean ing ful dif fer ence in rCBF ra tios be tween host and al ter per son al ity states. Our find ings sug gest that orbitofron tal and left (dom i nant hemi sphere) lat eral tem poral re gions are af fected in dissociative iden tity dis or der. A rep li ca tion of this study on a larger group of drugfree dissociative pa tients and var i ous psy chi at ric con trol groups would lead to more de fin i tive find ings. Key Words: SPECTdissociative iden tity dis or derim ag ingre gional ce re bral blood flow