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Montenigro PH, Alosco ML, Martin BM, Daneshvar DH, Mez J, Chaisson CE, Nowinski CJ, Au R, McKee AC, Cantu RC, McClean MD, Stern RA, Tripodis Y. Cumulative Head Impact Exposure Predicts Later-Life Depression, Apathy, Executive Dysfunction, and Cognitive Impairment in Former High School and College Football Players. J Neurotrauma 2016; 34:328-340. [PMID: 27029716 DOI: 10.1089/neu.2016.4413] [Citation(s) in RCA: 342] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The term "repetitive head impacts" (RHI) refers to the cumulative exposure to concussive and subconcussive events. Although RHI are believed to increase risk for later-life neurological consequences (including chronic traumatic encephalopathy), quantitative analysis of this relationship has not yet been examined because of the lack of validated tools to quantify lifetime RHI exposure. The objectives of this study were: 1) to develop a metric to quantify cumulative RHI exposure from football, which we term the "cumulative head impact index" (CHII); 2) to use the CHII to examine the association between RHI exposure and long-term clinical outcomes; and 3) to evaluate its predictive properties relative to other exposure metrics (i.e., duration of play, age of first exposure, concussion history). Participants included 93 former high school and collegiate football players who completed objective cognitive and self-reported behavioral/mood tests as part of a larger ongoing longitudinal study. Using established cutoff scores, we transformed continuous outcomes into dichotomous variables (normal vs. impaired). The CHII was computed for each participant and derived from a combination of self-reported athletic history (i.e., number of seasons, position[s], levels played), and impact frequencies reported in helmet accelerometer studies. A bivariate probit, instrumental variable model revealed a threshold dose-response relationship between the CHII and risk for later-life cognitive impairment (p < 0.0001), self-reported executive dysfunction (p < 0.0001), depression (p < 0.0001), apathy (p = 0.0161), and behavioral dysregulation (p < 0.0001). Ultimately, the CHII demonstrated greater predictive validity than other individual exposure metrics.
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Affiliation(s)
- Philip H Montenigro
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,2 Department of Anatomy and Neurobiology, Boston University School of Medicine , Boston, Massachusetts
| | - Michael L Alosco
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts
| | - Brett M Martin
- 3 Data Coordinating Center, Boston University School of Public Health , Boston, Massachusetts
| | - Daniel H Daneshvar
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts
| | - Jesse Mez
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,4 Department of Neurology, Boston University School of Medicine , Boston, Massachusetts
| | - Christine E Chaisson
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,3 Data Coordinating Center, Boston University School of Public Health , Boston, Massachusetts.,5 Department of Biostatistics, Boston University School of Public Health , Boston, Massachusetts
| | - Christopher J Nowinski
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,6 Concussion Legacy Foundation , Waltham, Massachusetts
| | - Rhoda Au
- 4 Department of Neurology, Boston University School of Medicine , Boston, Massachusetts.,7 Framingham Heart Study, Boston University School of Medicine , Boston, Massachusetts
| | - Ann C McKee
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,4 Department of Neurology, Boston University School of Medicine , Boston, Massachusetts.,8 Department of Pathology, Boston University School of Medicine , Boston, Massachusetts.,9 VA Boston Healthcare System , Boston, Massachusetts
| | - Robert C Cantu
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,6 Concussion Legacy Foundation , Waltham, Massachusetts.,10 Department Neurosurgery, Boston University School of Medicine , Boston, Massachusetts.,11 Department of Neurosurgery, Emerson Hospital , Concord, Massachusetts
| | - Michael D McClean
- 12 Environmental Health, Boston University School of Public Health , Boston, Massachusetts
| | - Robert A Stern
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,2 Department of Anatomy and Neurobiology, Boston University School of Medicine , Boston, Massachusetts.,4 Department of Neurology, Boston University School of Medicine , Boston, Massachusetts.,10 Department Neurosurgery, Boston University School of Medicine , Boston, Massachusetts
| | - Yorghos Tripodis
- 1 Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine , Boston, Massachusetts.,5 Department of Biostatistics, Boston University School of Public Health , Boston, Massachusetts
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Montenigro PH, Bernick C, Cantu RC. Clinical features of repetitive traumatic brain injury and chronic traumatic encephalopathy. Brain Pathol 2015; 25:304-17. [PMID: 25904046 PMCID: PMC8029369 DOI: 10.1111/bpa.12250] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 02/05/2015] [Indexed: 12/14/2022] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease characterized by a distinct pattern of hyperphosphorylated tau (p-tau). Thought to be caused by repetitive concussive and subconcussive injuries, CTE is considered largely preventable. The majority of neuropathologically confirmed cases have occurred in professional contact sport athletes (eg, boxing, football). A recent post-mortem case series has magnified concerns for the public's health following its identification in six high school level athletes. CTE is diagnosed with certainty only following a post-mortem autopsy. Efforts to define the etiology and clinical progression during life are ongoing. The goal of this article is to characterize the clinical concepts associated with short- and long-term effects of repetitive traumatic brain injury, with a special emphasis on new clinical diagnostic criteria for CTE. Utilizing these new diagnostic criteria, two cases of neuropathologically confirmed CTE, one in a professional football player and one in a professional boxer, are reported. Differences in cerebellar pathology in CTE confirmed cases in boxing and football are discussed.
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Affiliation(s)
- Philip H. Montenigro
- Chronic Traumatic Encephalopathy CenterBoston University School of MedicineBostonMA
- Department of Anatomy and NeurobiologyBoston University School of MedicineBostonMA
| | | | - Robert C. Cantu
- Chronic Traumatic Encephalopathy CenterBoston University School of MedicineBostonMA
- Department of Neurology and NeurosurgeryBoston University School of MedicineBostonMA
- Department of NeurosurgeryEmerson HospitalConcordMA
- Sports Legacy InstituteWalthamMA
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