title: Neuroimaging in amyotrophic lateral sclerosis: insights into structural and functional changes.
abstract: In the past two decades, structural and functional neuroimaging findings have greatly modified longstanding notions regarding the pathophysiology of amyotrophic lateral sclerosis (ALS). Neuroimaging studies have shown that anatomical and functional lesions spread beyond precentral cortices and corticospinal tracts, to include the corpus callosum; frontal, sensory, and premotor cortices; thalamus; and midbrain. Both MRI and PET studies have shown early and diffuse loss of inhibitory cortical interneurons in the motor cortex (increased levels of functional connectivity and loss of GABAergic neurons, respectively) and diffuse gliosis in white-matter tracts. In ALS endophenotypes, neuroimaging has also shown a diverse spreading of lesions and a dissimilar impairment of functional and structural connections. A possible role of PET in the diagnosis of ALS has recently been proposed. However, most neuroimaging studies have pitfalls, such as a small number and poor clinical characterisation of patients, absence of adequate controls, and scarcity of longitudinal assessments. Studies involving international collaborations, standardised assessments, and large patient cohorts will overcome these shortcomings and provide further insight into the pathogenesis of ALS.
authors.affiliation: ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy. Electronic address: achio@usa.net.
authors.forename: Adriano
authors.initials: A
authors.lastname: Chiò
authors.affiliation: Institute of Cognitive Sciences and Technologies, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy; Department of Nuclear Medicine, Karolinska Hospital, Stockholm, Sweden.
authors.forename: Marco
authors.initials: M
authors.lastname: Pagani
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Agosta
authors.affiliation: ALS Center, "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Calvo
authors.affiliation: Institute of Cognitive Sciences and Technologies, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy; Positron Emission Tomography Center IRMET S.p.A, Euromedic Inc, Torino, Italy.
authors.forename: Angelina
authors.initials: A
authors.lastname: Cistaro
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000503:physiopathology*; D001921:Brain / Q000473:pathology* / Q000502:physiology*; D006801:Humans; D059906:Neuroimaging / Q000379:methods*