title: Review: an update on clinical, genetic and pathological aspects of frontotemporal lobar degenerations.
abstract: The development of our understanding of frontotemporal dementia (FTD) has gathered pace over the last 10 years. After taking a back seat to Alzheimer's disease for many years FTD has emerged as a significant group of heterogeneous diseases often affecting people under the age of 65. FTD has also been brought into the spotlight as the major disease entities of the group have clinical, genetic and pathological links to motor neuron disease/amyotrophic lateral sclerosis, indicating that they form a disease spectrum. In this review, we overview how the pathological concept of frontotemporal lobar degeneration (FTLD) and the clinical concept of FTD evolved and show that FTLD, once thought of as a single disorder, represents a heterogeneous group of diseases with overlapping clinical symptoms, multiple causative genes and varying underlying pathology. We also provide a brief summary of the clinical manifestations, summarize the major genetic aspects and describe the main pathological features seen in the different subtypes of FTLD. We also summarize the correlations that exist between clinical presentations and pathological variants. An overview of the main pathogenic mechanisms is also provided.
authors.affiliation: Queen Square Brain Bank for Neurological Disorders, Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK.
authors.forename: Tammaryn
authors.identifier: http://orcid.org/0000-0001-7389-0348
authors.initials: T
authors.lastname: Lashley
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Rohrer
authors.affiliation: Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Mead
authors.affiliation: Queen Square Brain Bank for Neurological Disorders, Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK.
authors.forename: Tamas
authors.initials: T
authors.lastname: Revesz
mesh_terms: D057180:Frontotemporal Dementia / Q000235:genetics / Q000473:pathology*; D057174:Frontotemporal Lobar Degeneration / Q000235:genetics / Q000473:pathology*; D006801:Humans; D016472:Motor Neuron Disease / Q000235:genetics / Q000473:pathology*
keywords: FUS; TDP-43; classification; frontotemporal dementia; frontotemporal lobar degeneration; pathology; tau