Testing the diagnostic accuracy of [18F]FDG-PET in discriminating spinal- and bulbar-onset amyotrophic lateral sclerosis

• Published in: European journal of nuclear medicine and molecular imaging Vol. 46; no. 5; pp. 1117 - 1131
• Main Authors: Sala, Arianna, Iaccarino, Leonardo, Fania, Piercarlo, Vanoli, Emilia G., Fallanca, Federico, Pagnini, Caterina, Cerami, Chiara, Calvo, Andrea, Canosa, Antonio, Pagani, Marco, Chiò, Adriano, Cistaro, Angelina, Perani, Daniela
• Format: Journal Article Web Resource
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2019; Springer Nature B.V; Springer
• Subjects: [18F]FDG-PET; Accuracy; Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - diagnostic imaging; Amyotrophic Lateral Sclerosis - metabolism; Amyotrophic Lateral Sclerosis/diagnostic imaging/metabolism; Biomarkers; Brain; Brain mapping; Brain metabolism; Cardiology; Cerebellum; Correlation analysis; Cortex (motor); Diagnosis; Diagnosis, Differential; Diagnostic systems; Female; Fluorodeoxyglucose F18; Human health sciences; Humans; Imaging; Male; Medical diagnosis; Medicine; Medicine & Public Health; Medulla Oblongata - diagnostic imaging; Metabolism; Middle Aged; Motor Cortex - metabolism; Motors; Nuclear Medicine; Occipital lobe; Oncology; Original Article; Orthopedics; Patients; Phenotypes; Positron emission; Positron emission tomography; Radiologie, médecine & imagerie nucléaire; Radiology; Radiology, nuclear medicine & imaging; Regional analysis; Sciences de la santé humaine; Sensitivity and Specificity; Somatosensory cortex; Spine - diagnostic imaging; Tomography; Biomarkers; Amyotrophic lateral sclerosis; Diagnosis; Brain metabolism; [18F]FDG-PET
• ISSN: 1619-7070; 1619-7089; 1619-7089
• DOI: 10.1007/s00259-018-4246-2

Purpose The role for [18F]FDG-PET in supporting amyotrophic lateral sclerosis (ALS) diagnosis is not fully established. In this study, we aim at evaluating [18F]FDG-PET hypo- and hyper-metabolism patterns in spinal- and bulbar-onset ALS cases, at the single-subject level, testing the diagnostic value in discriminating the two conditions, and the correlations with core clinical symptoms severity. Methods We included 95 probable-ALS patients with [18F]FDG-PET scan and clinical follow-up. [18F]FDG-PET images were analyzed with an optimized voxel-based-SPM method. The resulting single-subject SPM-t maps were used to: (a) assess brain regional hypo- and hyper-metabolism; (b) evaluate the accuracy of regional hypo- and hyper metabolism in discriminating spinal vs. bulbar-onset ALS; (c) perform correlation analysis with motor symptoms severity, as measured by ALS-FRS-R. Results Primary motor cortex showed the most frequent hypo-metabolism in both spinal-onset (∼57%) and bulbar-onset (∼64%) ALS; hyper-metabolism was prevalent in the cerebellum in both spinal-onset (∼56.5%) and bulbar-onset (∼55.7%) ALS, and in the occipital cortex in bulbar-onset (∼62.5%) ALS. Regional hypo- and hyper-metabolism yielded a very low accuracy (AUC  <  0.63) in discriminating spinal- vs. bulbar-onset ALS, as obtained from single-subject SPM-t-maps. Severity of motor symptoms correlated with hypo-metabolism in sensorimotor cortex in spinal-onset ALS, and with cerebellar hyper-metabolism in bulbar-onset ALS. Conclusions The high variability in regional hypo- and hyper-metabolism patterns, likely reflecting the heterogeneous pathology and clinical phenotypes, limits the diagnostic potential of [18F]FDG-PET in discriminating spinal and bulbar onset patients.