CONCUSSION Update. Financial Disclosure

Transcription

1 WORKSHOP I CONCUSSION Update Financial Disclosure Dr. John Seals has no relevant financial relationships with commercial interests to disclose. Objectives for this Workshop Review the history of the word & concept Review current definition of concussion Discuss recent medical concepts which may influence how we think of concussion in future Discuss how changes in the definition of a word impact various areas of our society

2 Juliet: "What's in a name? That which we call a rose By any other name would smell as sweet." Romeo and Juliet (II, ii, 1 2) William Shakespeare ( ) Is that true? So what s with the word Concussion? Concussion (n.) c.1400, from Latin concussionem (nom. concussio) "a shaking," noun of action from pp. stem of concutere "shake violently," from com "together" (see com ) + quatere "to shake" (see quash). Modern brain injury sense is from 1540s. concuss (v.) 1590s, "to shake violently," from Latin concuss, pp. stem of concutere "to dash together, shake violently" (see concussion). Meaning "to give a concussion to the brain" is from 1680s. EVOLUTION OF A CONCEPT Confusion began in ancient times when no distinction was made between the transient effects of concussion and severe traumatic brain injury. The first clear separate recognition of concussion was made by the Persian physician, Rhazes, in the 10th century. In the 13th century, Lanfrancus promoted the concept of brain "commotion. However, other Renaissance physicians continued to obscure this concept By the 18th century, a variety of hypotheses for concussion had emerged. The 19th century discovery of petechial hemorrhagic lesions in severe traumatic brain injury led to these being posited as the basis of concussion, and a similar logic was used later to suggest diffuse axonal injury was responsible.

3 40Annual th Symposium on on Sports Sports Medicine Symposium January 17 19, CONCUSSION Definition A complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces. MEDICAL AREAS INVOLVED Physiology/pathophysiology Neuropathology Epidemiology Management protocols Genetic susceptibility THE EVENT (and its Consequences) Forces and Vectors or Vectors and Forces Scales: Anatomical/Time

4 Forces and Vectors or Vectors and Forces Applied forces over short time interval overcome integrity of interfaces between subcomponents of tissue Rotational forces amplify the stresses on and within brain tissues Tissue density influences type of response to the applied forces Scales: Anatomical/Time Blood vessels/brain tissue Cortex/White Matter Astrocyte glial cells/neuron Astrocyte glial cells/axon External Forces: Produce linear, rotational, or angular movement of the brain. In rotational movement, the head turns around its center of gravity, and in angular movement it turns on an axis not through its center of gravity. The amount of rotational force is now thought to be the major component in concussion and its severity. Recent studies with athletes indicate that the amount of force and the location of the impact are not necessarily correlated with the severity of the concussion or its symptoms, and have called into question the threshold for concussion previously thought to exist at around 70 75g

5 The ultimate results of these forces is a migration of potassium from within the cell into the extracellular space with subsequent release of glutamate which potentiates further extracellular potassium shift, in turn resulting in membrane depolarization and suppression of nerve activity. In an effort to restore ion balance, the sodium potassium ion pumps increase activity, which, results in excessive ATP (adenosine triphosphate) consumption and glucose utilization, along with altered blood flow, leads to an energy crisis FUTURE CONTRIBUTIONS FROM MEDICAL SECTORS NEURORADIOLOGY GENETICS TREM2 variant associated with Alzheimer disease Alzheimer disease increased risk from variations of the APOE gene The e4 version of the APOE gene increases an individual's risk for developing late onset Alzheimer disease. People who inherit one copy of the APOE e4 allele have an increased chance of developing the disease; those who inherit two copies of the allele are at even greater risk. The APOE e4 allele may also be associated with an earlier onset of memory loss and other symptoms. How we define and understand the meaning of the word has had significant impact in various areas of our society Participants Coaches Athletic Trainers Parents Athlete Industry Manufactures Equipment Evaluators Software developers Systems developers Media Print Radio T.V. Internet Legal Legislative Liability Regulatory

6 January 17 19, 2012 EDUCATION & AWARENESS PROGRAMS* Coaches* How easy is it to adapt coaching styles to new rules (not just concussion related) Athletic Trainers* Responsibility for identifying and monitoring concussion protocols that may, in fact, vary from one district to another. *Certification requirements? Parents: How wide is the range of understanding & attitude regarding concussion? Physicians: How wide is the range of understanding & attitude regarding concussion? Responsibility for evaluating concussion, a rapidly shifting landscape. THE SCIENCE OF IT ALL Virginia Tech STAR Stanford mouth guard sensors INDUSTRY/ ENGINEERING/ TECHNOLOGY Equipment Manufactures Equipment Evaluators: setting standards for the future? Software developers Systems for evaluation/management

7 Print Radio TV Internet THE MEDIA Information: Who has it, how up to date is it, and how relevant is it to your situation? Misinformation: Cherry picking blogs and TV special reports Most have a bias if not an axe to grind. Disinformation: Intentional distortion and misrepresentation of available data, potentially for financial gain. NEUROLOGY TODAY Editorial review

8 Neurology Today, October 4, 2012, 12:19 pg 8 review of Lehman, et al article However, both the study authors and experts who reviewed the report note that for at least two reasons findings from the study should not be regarded as conclusive: the total number of deaths from neurological causes in the football playing cohort was small, statistical estimates for mortality ratios imprecise; and the data used for the study was lacking in information about concussions, injuries, or other non football related risk factors that may have contributed to neurological death at the individual level. The 800 lbs. gorilla in the room (personal opinion) The study group (those who died) were identified as having played in the NFL between 1959 and 1988.a time period when use of anabolic androgenic steroids (AAS) was at high titer, and not just in the NFL. I have not been able to find a study that includes any attempt to control for this variable in those high level athletes in the NFL. This is not a trivial issue. Harrison G. Pope, MD; David L. Katz, MD, JD, Psychiatric and Medical Effects of Anabolic Androgenic Steroid Use: A Controlled Study of 160 Athletes Arch Gen Psychiatry. 1994;51(5): SUMMARY 1. We have come a long way in short period of time in understanding mechanisms and consequences of brain dysfunction/injury associated with concussion in sports. 2. We have not learned everything we need to know. 3. There are some innovative and cleaver minds currently engaged in solving some of the pressing problems associated with concussions. 4. We can be optimistic that many of the issues we see as insurmountable today will be resolved in the next few years. 5. There will continue to be mountains of data available to justify yearly update programs stay tuned. WORKSHOP I QUESTIONS & COMMENTS

9 BRAIN ANATOMY