Concussion The Basic Science Arturo Aguilar MD Boston University June 1, 2011

Disclosure Neither I, Arturo Aguilar, nor any family members, have any relevant financial relationships to be discussed, directly or indirectly, referred to or illustrated with or without recognition within the presentation

Objectives - History - Incidence - Definition - Pathology - Symptoms / Diagnosis - Grading - Risk

History A short lived period of posttraumatic neurologic dysfunction followed by full recovery has been described for over 3,000 years. 1 From the Latin term cerebrum commotum 2 “...paralysis of cerebral function” Dr. LaFrancus (13 th century) 2

Incidence Approximately million concussions each year in the U.S. 3 10% of college football players sustain brain injuries each season. 4 Concussions are the second most common injury in college football and women's soccer. Fourth most common in men's soccer, field hockey, women's volleyball. 5 Up to 85% of concussions go undiagnosed. 6

Consensus Guidelines International Symposia on Concussion in Sport (Vienna 2001, Prague 2004, Zurich 2008) 7,9 IIHF, FIFA, IOC Physicians, Neuropsychologists, sports administrators, basic scientists Original research, previous guidelines Level C evidence

Definition A complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces. [There are] several common features... (Consensus Statement of Concussion in Sport 3 rd International Conference on Concussion in Sport. Zurich 2008)

Definition 7 Common Features Concussion may be caused either by a direct blow to the head, face, neck, or elsewhere on the body with an “impulsive” force transmitted to the head. Typically results in the rapid onset of short lived impairment of neurologic function that resolves spontaneously....acute clinical symptoms largely reflect a functional disturbance rather than a structural injury.

Definition 7 Concussion results in a graded set of clinical symptoms that...may not involve loss of consciousness. Resolution of clinical/cognitive symptoms typically follows a sequential course [but]...in a small percentage of cases, post-concussive symptoms may be prolonged. No abnormality seen on standard structural neuroimaging.

Pathophysiology 1 No existing animal or other experimental model that accurately reflects a sporting concussive injury. In animal models there is a complex cascade of biochemical, metabolic, and gene expression changes. Unclear application to humans Anesthetized animals-blurs acute effects Symptom interpretation Different mechanical factors of smaller brains

Diagnosis / Symptoms 8 Observed Dazed, stunned Confusion, forgetful Clumsy/balance issues Speaks slowly Loss of consciousness Mood, behavior, personality changes Reported Headache, pressure Nausea, vomiting Dizzy Blurred vision photo/phono-phobia Foggy, fatigue, hazy Memory/focus issues Feeling down/not right

Clinical Domains of Concussion 7,8 Symptoms Physical Signs Behavioral Signs Cognitive Impairment Sleep Disturbance headache Loss of Consciousness Irritability Slowed Reaction Time Drowsiness Nausea/vomitingAmnesiaDepression Difficulty Concentrating Insomnia DizzyBalance IssuesAnxietyMemory Loss Fatigue Tonic Clonic Activity More EmotionalFoggy Feeling Blurred Vision Personality Changes Forgetful Photo/Phono- Phobia Dazed / Stunned Not Feeling Right

Diagnosis Difficulty 5 “Perhaps the most challenging aspect of managing...concussion[s] is recognizing the injury, especially in [those] with no obvious signs that a concussion has actually occurred.” (NATA Position Statement: Management of Sport Related Concussions. 2004) Rationalizing symptoms Uneducated regarding the seriousness Fear of limiting participation Popular media around professional return to play

Concussion Grading 7 25 concussion grading / management systems (2004) 4,11 Symptoms, LOC Lack evidence Abandon grading scales and (simple vs complex) classifications. (Zurich 2008) Second Impact Syndrome

Concussion and Risk: Fact or Fiction 7 -If you had loss of consciousness you had a more severe concussion. Fiction -The majority of concussion symptoms last 7-10 days. Fact -If you have had a concussion in the past your next is likely to last longer. Fact

Concussion and Risk: Fact or Fiction 3,9 -Once you sustain a concussion, you are 3-4x more likely to sustain a concussion again. Fact -If you have the A4 allele of the Apo E4 gene, you are more likely to sustain a concussion than those who do not. Fiction -

Concussion and Risk: Fact or Fiction 3,9 -If you wear the proper protective gear you are less likely to sustain a concussion. Fiction -By modifying some rules in sport, we may be able to reduce the risk of concussion in athletes. Possibly

Summary -Concussions are common -Diagnosis: Mechanism + sign/symptom -Think about the reasons we miss concussions -There is a consensus statement to help guide diagnosis and management -There are still many things we don't know yet, these are just guidelines.

References 1 McCrory P, Johnston K., Mohtadi N., Meeuwisse W” Evidence-Based Review of Sport-Related Concussion: Basic Science” Clinical Journal of Sports Medicine. (2005): Vol15 Num 6 2 Solomon G, Johnston K, Lovell M. The Heads-Up on Sport Concussion. United Graphics, USA Davis G, Iversion G, Guskiewicz K, Ptito A, Johnston K. “Contributions of neuroimaging, balance testing, electrophysiology and blood markers to the assessment of sport-related concussion” British Journal of Sports Medicine. (2009); 43 4 Asplund C, McKeag D, Olsen C. “Sport-Related Concussion. Factors Associated With Prolonged Return to Play” Clinical Journal of Sports Medicine (2004); 14: Guskiewicz K, Bruce S, Cantu R, Ferrara M, Kelly J, McCrea M, Putukian M, McLeod T. “National Athletic Trainers' Association Position Statement: Management of Sport-Related Concussion” Journal of Athletic Training (2004); 39(3): Harmon MD, Kimberly “Assessment and Management of Concussion in Sports.” American Family Physician. (1999) ; 60: Harmon MD, Kimberly “Assessment and Management of Concussion in Sports.” American Family Physician. (1999) ; 60: McCrory, Johnston, Meeuwisse, Aubry, Cantu, Dvorak, Kelly “Summary and Agreement Statement of the 3 nd International Conference on Concussion in Sport, Zurich, 2008.” Clinical Journal of Sports Medicine. (2009) Vol 19 Number 3 7 McCrory, Johnston, Meeuwisse, Aubry, Cantu, Dvorak, Kelly “Summary and Agreement Statement of the 3 nd International Conference on Concussion in Sport, Zurich, 2008.” Clinical Journal of Sports Medicine. (2009) Vol 19 Number 3 “Heads Up Facts for Physicians About Mild Traumatic Brain Injury (MTBI)” U.S. Department of Health and Human Services. 8 “Heads Up Facts for Physicians About Mild Traumatic Brain Injury (MTBI)” U.S. Department of Health and Human Services. McCrory, Johnston, Meeuwisse, Aubry, Cantu, Dvorak, Graf-Baumann, Kelly, Lovell, Schamasch “Summary and Agreement Statement of the 2 nd International Conference on Concussion in Sport, Prague 2004.” Clinical Journal of Sports Medicine. (2005) Vol 15, Number 2 9 McCrory, Johnston, Meeuwisse, Aubry, Cantu, Dvorak, Graf-Baumann, Kelly, Lovell, Schamasch “Summary and Agreement Statement of the 2 nd International Conference on Concussion in Sport, Prague 2004.” Clinical Journal of Sports Medicine. (2005) Vol 15, Number 2 10 Kissick J, Johnston K. “Return to Play After concussion” Clinical Journal of Sports Medicine. (2005); 15: