STUDY OF REGIONAL CEREBRAL BLOOD-FLOW IN WEST SYNDROME

Focal cortical disturbances are frequent sequelae in West syndrome (WS ) even though it is a generalized epileptic syndrome. Functional neuro imaging was used to determine whether focal perfusion abnormalities ex ist at WS onset and change during evolution. We studied regional cereb ral blood flow (rCBF) at different stages of WS. Mean CBF (mCBF) and r CBF were measured using SPECT (single photon emission computed tomogra phy) and Xe-133 in 13 WS patients: at onset (20 cases), just after ste roids (17 cases), and after a mean follow-up of 2 years (26 cases). At WS onset, interictal mCBF was increased as the result of foci of hype r- and hypoperfusion, which were, respectively, mainly located in the frontal and posterior cortex. Just after steroid therapy, mCBF decreas ed without any focal predominance. During follow-up, hypoperfused foci remained unchanged whereas the frontal hyperperfused foci decreased a fter spasm control. Our results show that focal abnormalities are pres ent at WS onset. Focal hypoactivity could reflect a cortical lesion re sponsible for WS and focal hyperactivity could play a role in the pers istence of generalized epilepsy.