Abstract TMP63: Structural Network Changes In Children With Moyamoya Disease Prior To Surgical Intervention

Purpose: Moyamoya disease/syndrome (MMD) is a progressive steno-occlusive disease involving the intracranial arterial circulation. Long term stenosis/hypoperfusion can lead to intellectual disability and cognitive impairment even in the absence of documented infarct. We aim investigate any underlying network abnormalities in MMD patients with no apparent ischemic injury. Materials and Methods: We retrospectively reviewed children with MMD with normal appearing parenchyma on conventional MRI. Control patients were selected from our existing database. Clinical, surgical and demographic data, including degree of stenosis as measured semi-quantitatively on MRA, were collected. Patients with documented infarcts, low quality DTI, and NF1 were excluded from the analysis. Group and correlational connectometry with degree of stenosis were performed. Results: A total of 28 patients were reviewed with 16 patients included in the study. Median (and interquartile range) age was 10.5 (8.5 - 13.5). Between group connectometry analysis identified infratentorial and supratentorial decreased connectivity in patients compared to controls, specifically in: middle cerebellar peduncle, corpus callosum, right parietopontine tract, superior cerebellar peduncle, left inferior fronto-occipital fasciculus. (Figure 1) In addition, we found negative correlation between the degree of stenosis and structural connectivity of multiple white matter pathways. Conclusion: Our findings reveal abnormal structural connectivity in children with MMD in the absence of infarcts on conventional MRI. Connectomics offers a unique opportunity to study the effect of long-term stenosis/hypoperfusion on cerebellar-cerebral networks and provide new insights into the mechanism of the structural plasticity/reorganization in these patients before bypass surgery. Future research is needed to determine longitudinal network changes before and after surgery.