Head Trauma

Question 1

Concussion
Description
Pathology

Answer 1

• Transient but instant loss of neural function, followed by “recovery”
• No acute pathologic findings on brain imaging
• Actual structural changes include damage to mitochondria membranes and cytoskeletal abnormalities.
• Fiber injury may be present (DAI = diffuse axonal injury) w/ delayed axotomy (severing of axons)

Question 2

Chronic Traumatic Encephalopathy
Description (early / late)
Gross pathology
Microscopic pathology

Answer 2

• Chronic progressive neurodegenerative disease due to repetitive “mild” cranial trauma.
• Early (I-II) – emotional explositivity, headache, STM changes, concentration, sleep disturbance, depression
• Late (III-IV) – executive function, cognitive impairment, dementia, aggression, possibly motor issues
• Gross pathology includes atrophy, cavum septum pellucidum, pallor of pigmented nuclei (such as locus ceruleus), thalamic and mammillary atrophy.
• Microscopic pathology includes pTau intraneuronal / intraglial neurofibrillary inclusions, neuroaxonal loss, astrocytic tangles, and TDP-43 positive staining in effected areas.
• Interneuronal spreading of toxic Tau may occur by prion-like mechanism.

Question 3

Coup injuries

Answer 3

Occur w/ stationary or moving heads

Question 4

Contrecoup injuries

Answer 4

Usually seen in abrupt deceleration of heads in motion. Anterior / middle cranial fossae are rough in adult.

Question 5

Ecchimosis
Description
Example

Answer 5

Looks like a bruise, but is caused by oozing of blood from trauma elsewhere.
•Basilar skull fracture may cause pooling of blood behind the ears or in orbits (raccoon eyes).

Question 6

Pontemedullary laceration

Answer 6

Caused by hyperextension of head, such as in being rear-ended in a car. Rarely survivable

Question 7

Subdural hemorrhage in an infant

Answer 7

Marker for possible inflicted trauma (“shaking”). Abuse.

Brain matter in infants is softer than in adults b/c it is not myelinated yet.

Question 8

Trauma in infants due to shaking

Answer 8

• Pathology may include subdural hemorrhage, ocular retinal hemorrhage, and intracranial mass effect.
• Cellular pathology includes axonal shearing injury, mainly in centrum semiovale, dorsolateral brainstem, and corpus callosum.
• Brain may swell → herniation