A Clinical Approach to the Diagnosis of Traumatic Encephalopathy Syndrome: A Review

Abstract

Importance: Chronic traumatic encephalopathy (CTE) refers to pathologic changes that have been found in some individuals with a history of repetitive traumatic impact to the head (hereinafter referred to as head trauma). These changes cannot be assessed during the clinical evaluation of a living patient.

Observations: The neuropathologic features, taxonomy, history, role of biomarkers in diagnosis, and existing criteria of CTE are reviewed. Previous criteria have been proposed to approach the living patient; however, a unified, specific approach is needed for the practicing clinician. We propose a new diagnostic construct for the clinical syndrome associated with repetitive exposure to head trauma: traumatic encephalopathy syndrome. This clinical paradigm will provide the framework for a diagnosis of probable, possible, and unlikely traumatic encephalopathy syndrome, with included discussion regarding the minimum exposure, nature of the clinical course, and additional clinical features needed for diagnosis.

Conclusions and relevance: While prospective longitudinal studies are ongoing to further elucidate the association of exposure to head trauma, clinical features, and the development of pathologic changes, a corresponding clinical construct for diagnosis is necessary.

Conflict of interest statement

Conflict of Interest Disclosures

Dr. Eckner reported receiving research funding from grant 1 K23 HD078502-01A1 from the National Institutes of Health (NIH), the National Collegiate Athletics Association, the US Department of Defense, the University of Michigan Injury Center, and the Foundation for Physical Medicine and Rehabilitation.

Dr. Paulson reported receiving support from the NIH and has a research contract with Ionis Pharmaceuticals.

Dr. Kutcher reported serving as a consultant for ElMindA, the National Basketball Association, the National Hockey League Players’ Association, and the National Football League Players’ Association.

No other disclosures were reported.

Figures

Figure. Initial Clinical Approach to the Patient With Neurocognitive Problems and Possible Traumatic Encephalopathy Syndrome (TES)

This model includes patients with a duration of neurocognitive problems for longer than 2 years. For a patient to be considered for a diagnosis of TES, the neurocognitive complaints or decline must be beyond the expected course given the individual’s age and other medical issues. This flowchart is intended to provide a framework for the practicing physician; clinical judgment and assessment remain a necessary aspect of the diagnostic pathway. NDD indicates neurodegenerative disease. a Includes obstructive sleep apnea, migraine, mood disorder, substance abuse, medication effect, and “worried well” (ie, individuals who do not have a medical disorder but may visit a physician owing to psychological distress or need for reassurance). b Include emotional dysregulation, behavioral change, or motor disturbance. c Consider trauma-accelerated NDD vs typical NDD.