title: Clinical subtypes of chronic traumatic encephalopathy: literature review and proposed research diagnostic criteria for traumatic encephalopathy syndrome.
abstract: The long-term consequences of repetitive head impacts have been described since the early 20th century. Terms such as punch drunk and dementia pugilistica were first used to describe the clinical syndromes experienced by boxers. A more generic designation, chronic traumatic encephalopathy (CTE), has been employed since the mid-1900s and has been used in recent years to describe a neurodegenerative disease found not just in boxers but in American football players, other contact sport athletes, military veterans, and others with histories of repetitive brain trauma, including concussions and subconcussive trauma. This article reviews the literature of the clinical manifestations of CTE from 202 published cases. The clinical features include impairments in mood (for example, depression and hopelessness), behavior (for example, explosivity and violence), cognition (for example, impaired memory, executive functioning, attention, and dementia), and, less commonly, motor functioning (for example, parkinsonism, ataxia, and dysarthria). We present proposed research criteria for traumatic encephalopathy syndrome (TES) which consist of four variants or subtypes (TES behavioral/mood variant, TES cognitive variant, TES mixed variant, and TES dementia) as well as classifications of 'probable CTE' and 'possible CTE'. These proposed criteria are expected to be modified and updated as new research findings become available. They are not meant to be used for a clinical diagnosis. Rather, they should be viewed as research criteria that can be employed in studies of the underlying causes, risk factors, differential diagnosis, prevention, and treatment of CTE and related disorders.
authors.affiliation: Department of Anatomy and Neurobiology, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA.
authors.forename: Philip H
authors.initials: PH
authors.lastname: Montenigro
authors.affiliation: Department of Neurology, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Baugh
authors.affiliation: Behavioral Neurosciences Program, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Daneshvar
authors.affiliation: BU Alzheimer's Disease Center, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: Mez
authors.affiliation: BU Alzheimer's Disease Center, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA ; VA Boston Healthcare System, 150 S Huntington Avenue, Boston 02130, MA, USA.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Budson
authors.affiliation: Department of Neurology, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA ; Framingham Heart Study, National Heart, Lung and Blood Institute, 72 East Concord Street, Boston 02118, MA, USA.
authors.forename: Rhoda
authors.initials: R
authors.lastname: Au
authors.affiliation: Department of Neurology, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA ; Braintree Rehabilitation Hospital, 250 Pond Street, Braintree 02184, MA, USA.
authors.forename: Douglas I
authors.initials: DI
authors.lastname: Katz
authors.affiliation: Department of Neurosurgery, Boston University School of Medicine, 73 East Concord Street, Boston 02118, MA, USA ; Department of Neurosurgery, Emerson Hospital, 131 Old Road, Suite 820, Concord 01742, MA, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Cantu
authors.affiliation: Department of Anatomy and Neurobiology, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA ; BU Alzheimer's Disease Center, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA ; Department of Neurology, Boston University School of Medicine, 72 East Concord Street, Boston 02118, MA, USA ; Department of Neurosurgery, Boston University School of Medicine, 73 East Concord Street, Boston 02118, MA, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Stern