Selective arterial distribution of cerebral hyperperfusion in Fabry disease

Fabry disease is an X-linked recessive deficiency of lysosomal alpha -galac tosidase A associated with an increased risk of early onset cerebrovascular disease. The disorder is reported to affect the posterior circulation pred ominantly. This hypothesis was investigated directly by the measurement of regional cerebral blood flow with positron emission tomography (PET). Resti ng regional cerebral blood flow (rCBF) in 26 hemizygous patients with Fabry disease and 10 control participants was examined using (H2O)-O-15 and PET. Statistical parametric mapping (SPM{t}, SPM99) and PET images of patients and controls were produced. Significantly increased SPM{t} clusters were th en color coded and blended with a coregistered T1 magnetic resonance imagin g (MRI) template. Cerebral arterial territory maps were digitized and resca led. Custom OpenGL and ImageVision Library C++ code was written to allow a first-order affine transformation of the blended SPM{t} and MRI template on to the arterial territory map. The affine transformation was constrained by choosing corresponding cerebral landmark "tie points" between the SPM{t} b oolean OR MRI template images and the cerebral arterial territory maps. The data demonstrated that the posterior circulation is the predominant arteri al territory with a significantly increased rCBF in Fabry disease. No arter ial distribution had a decreased rCBF.