Abstract WP112: Iodine-123-iomazenil Spect Revealed Recovery Of Neuronal Viability In Association With Improvement Of Cognitive Dysfunction After Revascularization In Moyamoya Disease

Abstract

Background: Recent studies indicate 123I-iomazenil (123I-IMZ) SPECT could demonstrate a neuronal viability. Although cognitive dysfunction has been recognized as an important issue in adult moyamoya disease (MMD), standard neuroradiological methods to define such condition are not established. Aim: Relationship between cognitive function and 123I-IMZ SPECT before and after revascularization in MMD was firstly examined. Method: Fifteen patients whose cerebrovascular reactivities (CVRs) were decreased only on the treatment sides were studied. Cognitive function was examined using mini-mental scale examination (MMSE, cutoff 27) and frontal assessment battery (FAB, cutoff 16) before and 6 months after surgery. 123I-IMZ and 123I-iodoamphetamine SPECT with acetazolamide challenge were performed at the same timings. Radioreactivities of 123I-IMZ SPECT at the regions with decreased CVR were investigated using affected-to-contralateral side ratio (ACR). Results: Eleven patients showed normal cognitive dysfunction before surgery (MMSE 29.5, FAB 18). In their preoperative 123I-IMZ SPECT, there were no regions with decreased uptakes (ACR 0.97). The cognitive functions and 123I-IMZ SPECT were not worsened after surgery (MMSE 29.9, FAB 18, ACR 0.99). By contrast, preoperative images of four patients with cognitive dysfunction (MMSE 23.8, FAB 14) showed decrease of 123I-IMZ uptakes, and the preoperative ACRs (0.82) were significantly lower than those of the normal group. Cognitive functions and 123I-IMZ uptakes of these four patients tended to ameliorate after revascularization (MMSE 27.5, FAB 15.5, ACR 0.92). Conclusion: Cognitive functions of MMD patients were associated with 123I-IMZ uptakes, and could improve after surgery with recoveries of neuronal viabilities.