Usefulness of Multi-Parametric MRI for the Investigation of Posterior Cortical Atrophy.

Andrea Arighi,Marco Bozzali,Pietro R Biondetti,Nereo Bresolin,Anna M Pietroboni,Laura Ghezzi,Mario Rango,Elio Scarpini,Chiara Fenoglio,Giorgio Fumagalli,Daniela Galimberti,Francisco J Esteban

doi:10.1371/journal.pone.0140639

Abstract

BackgroundPosterior Cortical Atrophy (PCA) is a neurodegenerative disease characterized by a progressive decline in selective cognitive functions anatomically referred to occipital, parietal and temporal brain regions, whose diagnosis is rather challenging for clinicians. The aim of this study was to assess, using quantitative Magnetic Resonance Imaging techniques, the pattern of regional grey matter loss and metabolism in individuals with PCA to improve pathophysiological comprehension and diagnostic confidence.MethodsWe enrolled 5 patients with PCA and 5 matched controls who all underwent magnetic resonance imaging (MRI) and spectroscopy (MRS). Patients also underwent neuropsychological and cerebrospinal fluid (CSF) assessments. MRI data were used for unbiased assessment of regional grey matter loss in PCA patients compared to controls. MRS data were obtained from a set of brain regions, including the occipital lobe and the centrum semiovale bilaterally, and the posterior and anterior cingulate.ResultsVBM analysis documented the presence of focal brain atrophy in the occipital lobes and in the posterior parietal and temporal lobes bilaterally but more pronounced on the right hemisphere. MRS revealed, in the occipital lobes and in the posterior cingulate cortex of PCA patients, reduced levels of N-Acetyl Aspartate (NAA, a marker of neurodegeneration) and increased levels of Myo-Inositol (Ins, a glial marker), with no hemispheric lateralization.ConclusionThe bilateral but asymmetric pattern of regional grey matter loss is consistent with patients’ clinical and neuropsychological features and with previous literature. The MRS findings reveal different stages of neurodegeneration (neuronal loss; gliosis), which coexist and likely precede the occurrence of brain tissue loss, and might represent early biomarkers. In conclusion, this study indicates the potential usefulness of a multi-parametric MRI approach for an early diagnosis and staging of patients with PCA.

Highlights

Posterior Cortical Atrophy (PCA) is a neurodegenerative disease which is clinically characterized by a progressive and selective decline in visual-processing skills and in other functions localized in the occipital, parietal and temporal brain regions
This study indicates the potential usefulness of a multi-parametric magnetic resonance imaging (MRI) approach for an early diagnosis and staging of patients with PCA
Earlier studies based on visual assessment of magnetic resonance (MR) images have consistently reported a bilateral pattern of posterior brain atrophy in cases of PCA [5,6,7,8,9,10,11,12]

Summary

Introduction

Posterior Cortical Atrophy (PCA) is a neurodegenerative disease which is clinically characterized by a progressive and selective decline in visual-processing skills and in other functions localized in the occipital, parietal and temporal brain regions. Earlier studies based on visual assessment of magnetic resonance (MR) images have consistently reported a bilateral pattern of posterior brain atrophy (i.e., affecting the occipital, parietal and temporal lobes) in cases of PCA [5,6,7,8,9,10,11,12]. Posterior Cortical Atrophy (PCA) is a neurodegenerative disease characterized by a progressive decline in selective cognitive functions anatomically referred to occipital, parietal and temporal brain regions, whose diagnosis is rather challenging for clinicians.

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