Moya Moya disease or syndrome ar characterized by a progressive or occlusion of the intracranial carotid arteries and their mainproximal branches, followed by the development of fragile neovessels at the base of the skull, leding to a high risk of both ischemic and hemorragic stroke over time. Moya Moya syndrome are associated to a variety of disease, which main frequent is sickle cell disease (SCD).

Among patients with SCD who had suffered from at least one ischemic stroke, the prevalence of moya moya syndrome was estimated up to 43%. In general, therapeutic strategies in Moya Moya to prevent first ever ou recurrent stroke can be divided into conservative medical treatment and surgical revascularisation (direct bypass, indirect bypass or combined bypass).

The aim of this study is to compare prognosis of patients with Moya Moya syndrome associated with sickle cell disease or not. The investigators retrospectiveluy analysed medical chart from 2010 to 2021 of patients with Moya Moya disease or syndrome at two French university hospitals (including a center of the french West Indies where prevalence of sickle cell disease is high). The diagnosis was based on angiography or MRI records showing uni- or bilateral stenosis of distal intracranial internal carotide arteries or middle cerebral arteries associated wirh classic collateral network.

Main endpoint will be comparison of a composite outcome defined as time from Moya Moya diagnosis to first or recurrent stroke or bad prognosis achivement (defined by modified Rankin score >2)

Inclusion criteria:

• age >=15
• patients at diagnosis of Moya Moya disease and syndrome

Exclusion criteria:

• misclassified patients
• clinical diagnosis of MM not confirmed by angiography or MRI

patients >=15 years of age at diagnosis of Moya Moya disease and syndrome from january 2010 to february 2021 at Montpellier and Martinique University Hospital

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