Clinical and radiological features of posterior cortical atrophy (PCA) in a GRN mutation carrier: a case report

Background and purpose: Posterior cortical atrophy (PCA) is a rare neurodegenerative syndrome, defined by a distinctive clinical-radiological profile, with Alzheimer's disease (AD) pathology accounting for the majority of cases. The aim of this report was to present the case of a patient with impairment of visual and constructional abilities as initial manifestations. Method: The patient underwent a multidimensional assessment, including neuropsychological evaluation, structural and functional imaging and genetic screening. Results: Neurological and neuropsychological assessment showed an impairment of constructive and visuo-spatial skills, associated with dyscalculia, simultanagnosia, optic ataxia and oculomotor apraxia. In accordance with the latest consensus criteria, a diagnosis of PCA was made. Consistent with the clinical findings, structural and functional imaging showed a peculiar pattern of atrophy with primary involvement of right parieto-occipital cortices, whereas cerebrospinal fluid biochemical analysis did not reveal a profile compatible with AD pathology. Genetic screening identified a known pathogenic GRN mutation. Conclusion: We present a case of PCA in a GRN mutation carrier in whom a concomitant AD pathological process was excluded. Consequently, although lacking histological data, our case suggests GRN-related pathology causative of PCA. Through this report we provide further evidence for a new neurodegenerative pathway leading to PCA, extending the clinical spectrum of GRN-associated phenotypes.