Brain perfusion defects by SPECT/CT and neurostat semi-quantitative analysis in two patients with congenital erythropoietic porphyria

Background: Congenital erythropoietic porphyria (CEP) is a rare autosomal recessively inherited disorder with chronic and relatively stable presentation. Till now brain blood ow derangements have been described only in acute hepatic porphyrias. We describe the rst ndings of brain perfusion defects, studied by single photon emission tomography/computed tomography (SPET/CT), in two patients affected by CEP, by using a semi-quantication anatomic-standardized voxel-based program compared with magnetic resonance imaging (MRI) results. Subjects and Methods: Two Pakistanis brothers were investigated for CEP conrmed by a genetic test. The disease was severe with: skin burning, mood depression and haemolytic anemia. Considering depression, patients underwent brain SPET/CT and MRI. Single photon emission tomography/ CT images were processed by neurostat semi-quantitative software. Data obtained were compared to a normal database and z-score images were generated. Results: In both patients we found several perfusion defects evident in transaxial slices and in z-score images obtained by neurostat processing. Magnetic resonance imaging was negative in both patients. Biochemical mechanisms inducing localized brain hypoperfusion are uncertain. However, mismatch between SPET/CT data and MRI was probably due to absence of necrosis. Conclusion: In our opinion, SPET/CT could have a key role in this setting of patients due to its high sensitivity and reliability in mild-to-moderate brain perfusion defects detection. Moreover, the quantitative analysis by using neurostat may allow to recognize even mild brain perfusion alterations, difficult to detect only visually.