Clinical appraisal of chronic traumatic encephalopathy: current perspectives and future directions

Purpose of review There are currently no consensus-based clinical diagnostic criteria for chronic traumatic encephalopathy (CTE). This review provides an update on recent literature pertaining to clinically relevant procedures that - presently or in the future - may be useful for the in-vivo detection, characterization, and/or prediction of CTE. Recent findings Preliminary evidence about the clinical manifestations of CTE has been accumulating via post-mortem medical record review and interviews of friends or family members of individuals with neuropathologically documented CTE. This evidence suggests that CTE is manifested clinically by changes in cognition (especially memory and executive functioning, with dementia later in the disease course), mood (especially, depression, apathy, and suicidality), personality and behavior (especially poor impulse control and behavioral disinhibition), and movement (including parkinsonism and signs of motor neuron disease). At the present time, evidence regarding CTE has not been confirmed in a prospective study of a cohort at risk for CTE. Summary On the basis of recent research in the fields of dementia and traumatic brain injury, several in-vivo procedures (including neurological examination, neuropsychological assessment, neuroimaging techniques, and blood and cerebrospinal fluid biomarkers) each have the potential to contribute unique information about the manifestations of CTE, including clinical and preclinical stages. More research is needed to develop a set of consensus diagnostic criteria that provide a reliable and valid indicator of neuropathologically verified CTE. Until such criteria are developed, the clinical assessment of CTE should be informed by modern research that is of relevance to traumatic brain injury and neurodegenerative diseases.