What price spectator sport thrills? And battered families, and military service.
A recent study published in JAMA Neurology of the donated brains of former American football players augments evidence on longterm impact of head injury: more years of play was associated with severity of adverse white matter changes and with greater phosphorylated tau protein accumulation. Both are in turn associated with dementia, representing a direct link between number of years of exposure to physical trauma, and dementia risk in athletes diagnosed with Chronic Traumatic Encephalopathy (CTE), independently of other neurodegenerative disorders,
Another finding of the study is the equal contribution to dementia risk of arteriosclerosis —small vessel disease common in aging and cardiovascular disease for pretty much anyone and everyone— illuminating further that multiple separate and combined pathways and pathologies add up to dementia (Alzheimer's as roughly 50%-70% of cases).
Given the widespread violence in our time, and the growing popularity of competitive contact sports in which, for example, heading the ball in women’s soccer exacts five times the brain damage in men’s, the current findings suggest risk all across society’s spectrum.
Most documented cases of chronic traumatic encephalopathy have occurred in athletes involved in contact sports … Other risk factors include being in the military, prior domestic violence, and repeated banging of the head.
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The investigators in the JAMA=published study regard the number of years of football play as a proxy for repetitive head impacts. They assessed arteriosclerosis, and white matter rarefaction as a reflection of
overall white matter integrity, including degree of myelin loss, extent of tissue attenuation or vacuolization around small blood vessels, and the density of reactive astrocytes.
and interviewed informants by telephone, in addition to using
recorded medical and clinical histories, including the presence, nature, and timeline of symptoms associated with cognition, behavior, or mood and daily functioning.
120 of the 180 donors had dementia diagnoses prior to death. All were age 40 or older —mean age at death 67.9 (12.7) years. — and diagnosed with CTE, the still-controversial sports hazard exposed by Dr. Bennet Omalu and colleagues in the journal Neurosurgery in 2005. The original group of 224 CTE-diagnosed men (excluded from the study were those deceased under age 40 and those with inadequate data) comprised what’s called a convenience sample, (or grab sample, or availability sample) a non-probability method drawing upon subjects easy to reach and willing to participate.
Race did not significantly affect white matter rarefaction, CTE stage, dorsolateral frontal cortex neurofibrillary tangles burden, or dementia.
The donations had been made to the Veterans Affairs–Boston University–Concussion Legacy Foundation brain bank as part of the ongoing Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) study. Anyone can receive news emails from that study by clicking that link to sign up.
<small>SOURCES & RESOUCES</small>:
On April 4, 2019, the reauthorization act passed in the House by a vote of 263-158. All Democrats voting joined by 33 Republicans voted for passage. New York Representative Elise Stefanik said Democrats, "...have refused to work with Republicans in a meaningful way," adding, the House bill will do nothing but "collect dust" in the GOP-controlled Senate.The bill has indeed been ignored by the Senate.
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