Neuropsychological Effects of Head Trauma in College Athletes

1. Neuropsychological Effects of Head Trauma in College Athletes Anthony C. Santucci, Ph.D. Manhattanville College Purchase, NY

2. Outline of Talk • Brief review of neuroanatomy • Sources of brain damage • Collisions in sports • Effects of collisions on the brain • Concussions • Description of recent study from my lab

3. Anatomy of a Neuron

4. Microstructure of a Neuron

5. Meninges of the Brain

6. Midline View of the Brain

7. Sources of Brain Damage • Vascular Accident (“stroke”) • Hemorrhage – bleeding in the brain • Infarct – brain damage due to deprivation of blood supply resulting from vascular constriction or obstruction (i.e., ischemia) • Diseases • Progressive neurodegenerative disorders (Alzheimer’s, Pick’s, or Parkinson’s disease) • Viral infection (e.g., spongiform encephalopathy)

8. Sources of Brain Damage (con’t) • Penetrating Wounds or Open-Head Injuries (e.g., gunshot, metal rod impalement, etc.; often are “sharp force trauma”) • Genetic Abnormalities (e.g., Huntington’s disease, etc.) • Tumors (e.g., glioma, meningioma, etc.) • Closed Head Injuries (i.e., Diffuse Axonal Injury -- axonal shearing; rotational/gravitational force -- “whiplash,” or contusions caused by “blunt force trauma”)

9. Definition of Closed Head Injury • Closed Head Injuries: biomechanical deformation of brain tissue • Closed Head Injuries can be caused by: • a foreign object concussing the head, i.e., blunt force trauma or “collision” (e.g., with another person’s head or body, hit by ball) • the head being concussed against a rigid object, i.e., blunt force trauma (e.g., goal post, boards, etc.), or • the head being subjected to a sudden & severe rotational and/or gravitational force (e.g., “whiplash”); most likely cause of Diffuse Axonal Injury (DAI) in traumatic brain injury

10. Brain Vasculature as it Relates to Head Trauma Bridging Veins

11. Collisions in Contact Sports • Participating in contact sports, especially football, ice hockey, gymnastics, wrestling, & boxing, makes one vulnerable to a closed head injury especially that derived from collisions (e.g., football causes approximately minor head injuries in approximately 20% of its participants [Cantu, 1998]). • Collisions involving the head in sports can occur in a variety of ways including…

12. Head-to-Ground Head-to-Elbow Back-to-Ground(reverberation) Head-to-Ground Head-to-Shoulder Head-to-Body “Heading” Top-to-Ground(compression)

13. Head-to-Head Front-to-Side Front-to-Top Top-to-Side Front-to-Front

14. Blunt Force Trauma-Induced Contusions Extensive blunt force trauma sustained in a vehicle accident The cerebral crest is especially vulnerable to damage caused by blunt force trauma Fall-induced blunt force trauma causing contra coup injury

15. Hematomas Subdural hematoma Epidural hematoma Subarachnoid hematoma from contra coup injury

16. Diffuse Cerebral Edema(i.e., swelling) Edema producing widened gyri and narrower sulci Acute closed cranial cavity edema producing herniation (pushing through) of the hippocampus

17. Boxing & Diffuse Cerebral Edema Edema

18. Neurocascade Events are Evidenced by Impact Trauma Schematic Courtesy of UCLA’s Brain Research Institute

19. Rotational & Gravitational Force Injuries

20. Diffuse Axonal Injury • DAI frequently results from sudden acceleration-deceleration impact that produces rotational forces, most often causing white matter lesions • DAI produces an anatomic & metabolic cascade: • → shearing of axons → edema → axoplasmic leakage → disruption of axonal transport → degeneration of the axon → neuron death • DAI is often undervisualized using current brain imaging techniques • DAI is a frequent cause of persistent vegetative state & morbidity

21. MRI scan demonstrating multiple foci of damage signal at the gray-white matter junction (arrow) and within the corpus callosum in a patient with DAI.

22. MRI scan demonstrating numerous small focal hemorrhages (arrows) consistent with DAI.

23. Noncontrast CT scan of a trauma patient with multiple petechial (pinpoint) hemorrhages (arrows) consistent with DAI.

24. Other Possible Effects Produced by Collisions • Second-impact syndrome (SIS) • Occurs when a second concussion is sustained while the athlete is still symptomatic and healing from a previous concussion. The second injury may occur from days to weeks following the first. Loss of consciousness is not required. The second impact is more likely to cause brain swelling and other widespread damage, and can be fatal. (Note, some authors contend this syndrome is the result of complications derived from Diffuse Cerebral Edema and, as such, should not be classified as a separate medical condition.) • Intra-cerebral hemorrhage • Bleeding that occurs within the brain that can affect neurological and mental functioning

25. Effects of Concussions • Posttraumatic amnesia (anterograde amnesia) • Retrograde amnesia • Mental Confusion & Disorientation • Headache • Nausea/Vomiting • Visual disturbance (blurred vision, double vision) • Dizziness • Slurred speech • Drowsiness • Loss of Consciousness

26. Problem of Defining Concussion • There is no widely accepted definition of concussion, especially that of Postconcussion Syndrome i.e., residual effects of concussion) • Committee of Head Injury Nomenclature of the Congress of Neurological Surgeons: • “Concussion is a clinical syndrome characterized by immediate & transient post-traumatic impairment of neural functions, such as alteration of consciousness, disturbances of vision, equilibrium, etc. due to brainstem involvement.” • However, other definitions exists:

27. Other Definitions of Concussion • Other definitions are based on: • Duration of unconsciousness • Duration of post-traumatic amnesia • Cantu (1986) based his definition on both duration of unconsciousness or amnesia

28. Cantu (1986) (adapted from Cantu, 1998)

29. American Academy of Neurology AAN defines concussion as a "alteration of mental status due to a biomechanical force affecting the brain." The AAN definition does not require a loss of consciousness. The AAN guidelines, break down concussion into three grades: • Grade 1: Transient confusion; NO loss of consciousness; symptomsclear in less than 15 minutes. • Grade 2: Transient confusion; NO loss of consciousness; Concussion symptoms or mental status abnormalities last longer than 15 minutes. • Grade 3: Any loss of consciousness, either brief (seconds) or prolonged (minutes).

30. 5-Grade Classification System (athleticadvisor.com) • Grade 0 • results when the head is struck or moved rapidly; characterized by a post injury headache and difficulty with concentration • Grade 1 • athlete appears stunned; no loss of consciousness (LOC); sensory difficulties resolve < 1min; “bell-rung” • Grade 2 • characterized by headache; cloudy senses > I min but no LOC; tinnitus, amnesia, irritability, confusion, or dizziness may be present • Grade 3 • LOC < 1 min; not comatose; same symptoms as grade 2 • Grade 4 • Grade 4 concussions are characterized by LOC of greater than one minute. The athlete will not be comatose, and will also exhibit the symptoms of the grade 2 and 3 concussions

31. Return-to-Play Decisions(Cantu, 1998)

32. Alternate 3-Grade Return-to-Play System(Familypracticenotebook.com) • I. Grade 1 • First Grade 1 Concussion • Return to play if asymptomatic for 15-20 minutes • Second Grade 1 Concussion • Requires formal examination by medical doctor • Return to play if asymptomatic for 1 week • Third Grade I Concussion • Terminate season • Requires formal examination by medical doctor • II. Grade 2 • First Grade 2 Concussion • Requires formal examination by medical doctor • Return to play if asymptomatic for 1 week • Second Grade 2 Concussion • Return to play if asymptomatic for 1 month • Third Grade 2 Concussion • Terminate Season • III. Grade 3 • First Grade 3 Concussion • Urgent neurological exam hospital ER • Consider head CT • Return to play guidelines • No participation for one month minimum • May return to play if asymptomatic for 1-2 weeks • Second Grade 3 Concussion • Terminate Season • Third Grade 3 Concussion • Terminate Sport

34. Rationale for Study • Head trauma sufficiently severe enough to produce a diagnosable concussion would be associated with changes in neuropsychological function, especially that within the memory domain • Assessed whether such neuropsychological alterations would be dependent upon: • Severity & frequency of concussion • Time since concussion

35. Method • Participants • UG participants in contact sports [lacrosse, soccer, ice hockey, &/or field hockey] with either: • A recent history of concussion (< 2 yrs) (N=5; 3M,2F) • A non-recent history of concussion (> 2 yrs) (N=6; 3M,3F) • No history of concussion (N=9; 6M,3F) • UGs who did not participate in a contact sport and who had no history of concussion (N=8; 5M,3F)

36. Participant Demographics

37. Materials & Procedure • General Concussion Reference Form • Subject Questionnaire Form • Repeatable Battery for the Assessment of Neuropsychological Status (RBANS; Randolph, 1998) • Postconcussion Syndrome Checklist • Stroop Task

38. Materials & Procedure (con’t) • RBANS • Uses standardized norms to assess five cognitive domains: • IMMEDIATE MEMORY • DELAYED MEMORY • VISUOCONSTRUCTIONAL/SPATIAL ABILITY • LANGUAGE • ATTENTION • Each sub-scale score contributes to an OVERAL TOTAL SCORE

39. Results on the RBANS

40. Results on the Stroop Test

41. Correlation Matrix for the two Athlete Concussed Groups *p < .05; #p = .10

42. Correlation Matrix for the Athlete/Recent Concussed Group *p < .05

43. Conculsions • Recent heady injury is associated with alterations in neuropsychological function, especially that which lie in the memory domain • These neuropsychological effects appears to resolve with time • Provocatively, participation in contact sports may produce sub-clinical cognitive impairments in the absence of a diagnosable concussion presumably resulting from the cumulative effects of multiple mild brain trauma

44. Limitations to the Research • Small N • Did not include football athletes • Used UGs at a Division-III school • Relied on self-report data for concussion information • Did not have pre-injury data • Used only one neuropsychological test

45. Future Research • We are presently looking more closely at whether concussed athletes show changes: • In EEG waves, esp. within the frontal and temporal lobes • In spatial memory with altering levels of task difficulty • On another neuropsychological test, this time assessing solely attention (d2 Test of Attention)

46. Thank You