The movie “Concussion”, starring Will Smith, is based on the true story of a neuropathologist (specialist who studies brain abnormalities) Bennet Omalu. Dr. Omalu was originally from Nigeria, and knew virtually nothing about U.S. football. In 2002, he was assigned to perform an autopsy on the brain of Pittsburgh Steelers center Mike Webster, who had died of a heart attack at age 50.
Initially, Dr. Omalu was puzzled at the normal appearance of the exterior of Webster’s brain. It did not fit what he knew to be the signs of trauma suffered by boxers whose heads are repeatedly bashed, and by players in other sports where helmets are also worn. In fact, some slides of interior tissue also revealed normal looking structures. There was nothing obvious to explain Webster’s poor cognitive function and loss of hand coordination during the last few years of his life.
Omalu was a patient and systematic detective. Eventually he was able to identify tiny dark structures termed “neurofibrillary tangles” similar to the abnormal masses of proteins in associated with Alzheimer’s disease. In fact, when he showed the slides to a former professor, that’s what the expert thought he was looking at. Omalu encouraged him to look more closely, at which point the professor asked why Omalu had brought him the brain of a boxer.
According to a story in The Atlantic:
“Dementia footballistica,” Hamilton joked. He kept going back to the slides. “This is crazy. This has never been identified before.”1
Football, brain injury and essential tremor
Robert W. Evans, a Houston-based neurologist, has a sub-specialty in headache medicine. He was curious about the incidence of migraines and other neurological conditions among retired NFL players. He conducted a pilot study using “a convenience sample of 50 retired players seen in my practice.”2
He found more than he anticipated. In addition to migraines and other headache pain, he found significantly higher rates of prevalence than in the general population for the following:
- Depression (reported by 78%)
- Anxiety (86%)
- Chronic non-headache pain (88%)
- Nocturnal enuresis (bedwetting, reported by 78% vs. 7% among normal retirees)
- Parkinson’s disease (4% compared to 1% in the general population)
As for essential tremor (ET), Evans’ retired athletes reported 22% occurrence, while in the general adult population ET occurs in about 5% of adults.
Today, there is a diagnostic term for people whose multiple head injuries result in predictable brain damage: chronic traumatic encephalopathy (CTE). Brain autopsies reveal numerous characteristic features from anatomic deformities to microscopic abnormalities like the previously mentioned neurofibrillary tangles. While no one knows if early concussion damage resolves completely – most cases of isolated concussion appear to have no lasting effects – the cumulative damage suffered by athletes involved in football, boxing, rugby, soccer, wrestling, etc. is irreversible.
Essential tremors and the thalamus
Aside from repeated head trauma, what causes ET for the majority of patients remains a mystery. The pathways for dysfunctional tremor signals in the brain are largely thought to originate in the part of the brain called the cerebellum. From there, “outflow pathways” lead to the thalamus, a small region deep in the brain. The thalamus has several functional centers. One of them, the VIM nucleus, forwards these abnormal movement messages to the motor cortex of the forebrain, and from there, outward to the hands, head, voice or other body part that manifests tremors.
In the case of ET caused by CTE, it is not yet determined what the pathways are, but the end result tremors appear identical to those in which a head injury never happened.
Organized sports in which concussive head blows occur will continue. At the Sperling Neurology Associates, it is our hope that better protection, and safer playing strategies, will be developed to prevent such damaging injuries.
Visit our website for more information on MRI-guided Focused Ultrasound for the treatment of essential tremor, and how to contact us.
1Jeanne Marie Laskas. “The Brain that Sparked the NFL’s Concussion Crisis.” The Atlantic, Dec. 2, 2015. https://www.theatlantic.com/health/archive/2015/12/the-nfl-players-brain-that-changed-the-history-of-the-concussion/417597/
2 Evans, RW. The Prevalence of Migraine and Other Neurological Conditions Among Retired National Football League Players: A Pilot Study. Practical Neurology. Nov-Dec. 2017. http://practicalneurology.com/2017/12/the-prevalence-of-migraine-and-other-neurological-conditions-among-retired-national-football-league-players-a-pilot-study/