Due to stretching forces placed on individual nerve cells
Pathology distributed throughout brain
Types
Concussion
Diffuse Axonal Injury (Moderate to Severe)
2. ∗ Due to stretching forces placed on individual nerve cells
∗ Pathology distributed throughout brain
∗ Types
∗ Concussion
∗ Diffuse Axonal Injury (Moderate to Severe)
Diffuse Brain Injury
3. ∗ Accidental Falls
∗ Vehicular accidents
∗ Child Abuse
∗ Assaults
∗ Gunshots
∗ Violent shaking of a child
∗ Sports related injuries
Causes
4. ∗ Diffuse axonal injury (DAI) is the predominant
mechanism of injury in 40% to 50% of traumatic brain
injuries (TBIs) requiring hospital admission in the United
States.
∗ A component of DAI is believed to be present in all motor
vehicle crashes (MVCs) where the patient has lost
consciousness
∗ Widespread axonal damage occurring after a mild,
moderate, or severe TBI
∗ Process takes approximately 12-24 hours
∗ One of the major causes of unconsciousness and
persistent vegetative state after head trauma
Diffuse Axonal Injury
5. ∗ Due to acceleration/deceleration to whtie matter +
hypoxia
∗ Significant mechanical disruption of nerve cells
∗ Cerebral hemispheres and brainstem
∗ High mortality rate
Diffuse Axonal Injury
6. ∗ Mostly microscopic damage, and it is often not visible on
imaging studies
∗ The main mechanical force that causes DAI is rotational
acceleration of the brain, resulting in unrestricted head
movement
∗ Rotational acceleration produces shearing and tensile
forces, and axons can be pulled apart at the microscopic
level
∗ Microscopic evaluation of the brain tissue often shows
numerous swollen and disconnected axons
∗ Rapid stretching of axons is thought to damage the
axonal cytoskeleton and, therefore, disrupt normal
neuron function
Diffuse Axonal Injury:Pathological
feature
7. ∗ Varies from mild to profound
∗ May be permanent or temporary
∗ Symptoms may appear immediately or over weeks,
months, years
∗ Diffuse axonal injury (DAI)
∗ Clinical signs:
∗ ↓ LOC
∗ ↑ ICP
∗ Decerebration or decortication
∗ Global cerebral edema
Diffuse Axonal Injury: Clinical
features
9. ∗ Defined as the result of the forceful motion of the head
causing a brief change in mental status for less than 30
minutes.
Concussion
10. ∗ 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.
∗ Concussion typically results in the rapid onset of short- lived
impairment of neurologic function that resolves spontaneously.
However in some cases symptoms and signs may evolve over
a number of minutes to hours.
∗ Concussion may result in neuropathological changes but the
acute clinical symptoms largely reflect a functional disturbance
rather than a structural injury and as such, no abnormality is
seen on standard structural neuroimaging studies.
∗ Concussion results in a graded set of clinical symptoms that
may or may not involve loss of consciousness. Resolution of
the clinical and cognitive symptoms typically follows a
sequential course. However it is important to note that in
some cases, post-concussive symptoms may be prolonged.
Concussion
11. ∗ Level of consciousness
∗ Variable period of unconsciousness or confusion
∗ Followed by return to normal consciousness
∗ Retrograde short-term amnesia
∗ May repeat questions over and over
∗ Associated symptoms
∗ Dizziness, headache, ringing in ears, and/or nausea
Concussion
Head Trauma -
12. ∗ No structural injury to brain
∗ Mild to moderate form of Diffuse Axonal Injury (DAI)
∗ Nerve dysfunction without anatomic damage
∗ In a concussion, certain chemical levels are altered at the
cellular level
∗ Blood supply to the brain decreases
∗ The brain’s demand for glucose increases
∗ Mismatch in fuel supply and demand
∗ Neuronal tissue vulnerability
∗ Brain needs time to recover
Concussion: Pathophysiology
13. Classification/Grading Guides
Guideline Grade 1 Grade 2 Grade 3
Cantu 1. No LOC
2. Posttraumatic amnesia <30
min
1. LOC > 5 min
OR
2. Posttraumatic amnesia
> 30 min
1. LOC > 5 min
OR
2. Posttraumatic
amnesia >24˚
Colorado 1. Confusion w/out amnesia
2. No LOC
1. Confusion w/ amnesia
2. No LOC
1. LOC
(of any duration)
AAN 1. Transient confusion
2. No LOC
3. Concussion syx, ms change
resolve w/in 5 min
1. Transient confusion
2. No LOC
3. Concussion syx, ms
change >15 min
1. LOC
(brief or prolonged)
Cantu
(Revised)
1. No LOC
OR
2. Posttraumatic amnesia
signs/syx < 30 min
1. LOC < 1 min
OR
2. Posttraumatic amnesia
>30 min, <24˚
1. LOC > 1min
OR
2. Posttraumatic
amnesia >24˚
OR
3. Post concussion
signs/syx > 7d
14. ∗ Neurological examination and assigning a GCS Score.
∗ Neuroimaging helps in determining the diagnosis and
prognosis and proposed treatment
∗ Neuropsychological assessment
Diagnosis
15. ∗ Computed tomography (CT)
∗ Rarely detected on CT ( 20% of DAI lesions are
hemorrhagic)
∗ Magnetic resonance imaging (MRI)
∗ Can show more details than CT as detecting injury
characteristics such as diffuse axonal injury
∗ However, MRI is not used in the emergency setting
∗ X-rays:
∗ Not much role
∗ Angiography:
∗ May be used to detect blood vessel pathology.
∗ Electroencephalography and transcranial doppler may
also be used.
Investigations
16. ∗ ABCD
∗ Pharmacotherapy
● Prolonged symptoms (sleep disturbance, anxiety)
● Modify underlying pathophysiology
∗ Upon return to play should not be on medication that
could mask symptoms
● Antidepressants?
● Physical Rest
● No training, playing, exercise, weights
● Beware of exertion with activities of daily living
● Cognitive Rest
● No television, extensive reading, video games?
● Caution re: daytime sleep
Management
17. ∗ Mild cases: Gradual resolution within 7-10 days
∗ Gradual return to work and social activities that does
not result in significant exacerbation of symptoms
Management
19. ∗ Majority (80-90%) resolve in short (7-10 day) period
∗ May take longer in children and adolescents
Recovery
20. ∗ Alzheimer's Disease: recent research suggests correlation
between head injury in early adulthood and AD later in life
∗ Parkinson's Disease: rare, but may occur
∗ Dementia Pugilistica: also known as chronic traumatic
encephalopathy, usually acquired from repetitive blows to the
head (boxers)
∗ Post-traumatic Dementia: long term memory problems,
caused by single, severe traumatic brain injury resulting in a
coma
Long Term Effects
21. • In the car...
o Wear seatbelt
o Head rest in proper position
o Children under the age of 13 should ride in the back seat
• Activities
o Wear a helmet
• Sports
o Wear protective gear
Prevention
22. ∗ Traumatic injuries affect more patients than all other
neurological conditions COMBINED
∗ At present, the best treatment is PREVENTION
Conclusion
23. 1.6 to 2.3 million sports concussions per year
Center for Disease Control 2006