Neuropsychological Effects of Head Trauma in College

Athletes

Anthony C. Santucci, Ph.D.

Manhattanville College

Purchase, NY

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

Anatomy of a Neuron

Microstructure of a Neuron

Meninges of the Brain

Midline View of the Brain

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)

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”)

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

Brain Vasculature as it Relates to Head Trauma

Bridging Veins

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…

Head-to-Ground

Back-to-Ground (reverberation)

Head-to-ShoulderHead-to-Body

Head-to-Ground

Top-to-Ground(compression)

Head-to-Elbow

“Heading”

Head-to-Head

Front-to-Top

Front-to-Side

Top-to-SideFront-to-Front

Blunt Force Trauma-Induced Contusions

The cerebral crest is especially vulnerable to damage caused by blunt

force trauma

Extensive blunt force trauma sustained in a vehicle accident

Fall-induced blunt force trauma causing contra coup injury

Hematomas

Epidural hematoma

Subarachnoid hematoma from contra coup injury

Subdural hematoma

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

Boxing & Diffuse Cerebral Edema Edema

                              

                     

                              

                     

Neurocascade Events are Evidenced by Impact Trauma

Schematic Courtesy of UCLA’s Brain Research Institute

Rotational & Gravitational Force Injuries

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

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.

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

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

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

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

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:

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

Cantu (1986) (adapted from Cantu, 1998)

Grade Loss of Consciousness

Duration of Amnesia

Grade 1 (mild)

None Less than 30 minutes

Grade 2 (moderate)

Less than 5 minutes

or 30 minutes or greater

but less than 24 hr

Grade 3 (severe)

5 minutes or greater

or 24 hr or more

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; symptoms clear 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).

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

Return-to-Play Decisions(Cantu, 1998)

Severity

Number of Concussion Sustained

First Second Third

Grade 1 May return if asymptomatic for 1 week

May return after 2 weeks if asymptomatic for at least 1 week

Terminate season; may return next year if asymptomatic

Grade 2 Return after being asymptomatic for 1 week

Wait at least 1 month; may return then if asymptomatic for 1 week; consider terminating season

Terminate season; may return next year if asymptomatic

Grade 3 Wait at least 1 month; may return if asymptomatic for 1 week

Terminate season; may return next year if asymptomatic

I. Grade 1 A.First Grade 1 Concussion

1.Return to play if asymptomatic for 15-20 minutes B.Second Grade 1 Concussion

1.Requires formal examination by medical doctor2.Return to play if asymptomatic for 1 week

C.Third Grade I Concussion 1.Terminate season

D.Requires formal examination by medical doctorII. Grade 2

A.First Grade 2 Concussion 1.Requires formal examination by medical doctor 2.Return to play if asymptomatic for 1 week

B.Second Grade 2 Concussion 1.Return to play if asymptomatic for 1 month

C.Third Grade 2 Concussion 1.Terminate Season

III. Grade 3 A.First Grade 3 Concussion

•Urgent neurological exam hospital ER •Consider head CT •Return to play guidelines

A.No participation for one month minimum B.May return to play if asymptomatic for 1-2 weeks

1.Second Grade 3 Concussion A.Terminate Season

2.Third Grade 3 Concussion A.Terminate Sport

Alternate 3-Grade Return-to-Play System (Familypracticenotebook.com)

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

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)

Participant Demographics

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

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

Results on the RBANS

Results on the Stroop Test

Correlation Matrix for the two Athlete Concussed Groups

PostConcussion Checklist

# of Yrs Since Last Concussion

Attention -.65*

Delayed Memory

-.61*

Total -.59*

Immediate Memory

+.53#

*p < .05; #p = .10

Correlation Matrix for the Athlete/Recent Concussed Group

PostConcussion Checklist

Severity/

Frequency of Head Injury

Delayed Memory

-.90*

Processing Speed on Stroop

+.90*

*p < .05

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

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

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)

Thank You