Chapter 11

Question 1

traumatic brain injury (TBI)

Answer 1

happens when a sudden, external, physical assault damages the brain
- TBI is a broad term that describes a vast array of injuries that happen to the brain. The damage can be: focal, diffuse

Question 2

focal damage

Answer 2

confined to one area of the brain
- contusions (visible)
- concussion (non-visible)
- chronic traumatic encephalopathy (CTE) brain degeneration suffered by professional football players
- hematomas (subdural and epidural)

Question 3

diffuse damage

Answer 3

happens in more than one area of the brain

Question 4

two ways TBIs may happen

Answer 4

closed brain injury, penetrating brain injury

Question 5

closed brain injury

Answer 5

• happen when there is a non-penetrating injury to the brain with no break in the skull
• a rapid forward or backward movement and shaking of the brain inside the bony skull (e.g., car accident or violently shaking a baby)
• diffuse axonal injuries (DAI)

Question 6

penetrating brain injury

Answer 6

• open head injuries
• happen when there is a break in the skull, such as when a bullet pieces the brain

Question 7

diffuse axonal injury (DAI)

Answer 7

a type of TBI that occurs due to shearing of a brain’s long connecting nerve fibers (axons) that happens when the brain is injured as it shifts and rotates inside the boney skull

Question 8

classifications of TBI based on the Glasgow coma scale (GCS)

Answer 8

mild (13-15), moderate (9-12), severe (below 8)

Question 9

symptoms of diffuse axonal injury (DAI)

Answer 9

• can present in a spectrum of neurological dysfunction
• can range from clinically insignificant to a comatose state
• most patients are identified to be severe and commonly have a GCS of less than 8

Question 10

etiology of DAI

Answer 10

• most common etiology involves high-speed motor vehicle accidents
• most common mechanism involves an accelerating and decelerating motion that leads to shearing forces to the white matter tracts of the brain
• commonly affects white matter tracts involved in the corpus callosum and brainstem

Question 11

coup contra coup

Answer 11

• coup injury refers to the brain damage that occurs directly under the point of impact
• coutra coup injury occurs on the opposite side of the brain from where the head is struck
  (when a blow is taken to one side of the skull/brain and then the skull/brain rocks back and forth in reaction)

Question 12

bad design of the skull

Answer 12

if brain slides against ethmoid ridge and/or sphenoid ridge, it can get wrecked

Question 13

ethmoid ridge

Answer 13

bone separating the hemispheres

Question 14

sphenoid ridge

Answer 14

bone separating frontal and temporal lobes

Question 15

one consequence of contusions

Answer 15

orbitofrontal cortex damage
- affects executive function

Question 16

clinical features of mild traumatic brain injury: initial presentation

Answer 16

• initial loss of consciousness lasting seconds to minutes, but not lasting longer than 30 minutes
• period of confusion (post-traumatic amnesia) lasting minutes to hours, but can last up to 24 hours
• any combination of headaches, neck ache, dizziness, and nausea
• typically no focal findings on the remainder of the neurological examination

Question 17

clinical features of mild traumatic brain injury: follow-up presentation

Answer 17

“neural injury”
- cognitive deficits (attention, memory, and executive function)
- behavioral deficits (depression, anxiety)

“non-neural injury”
- systemic deficits (head/neck ache, dizziness, poor sleep)

Question 18

recovery from a mild traumatic brain injury

Answer 18

• typical patient (loss of consciousness [LOC] <1-minute, post-traumatic amnesia [PTA] <20-40 minutes) usually recovers within 3 months
• if injury is more severe (LOC > 10 minutes, PTA > 4-6 hours) recovery can take months to years, or not at all
• older patients (>55 years) will take longer to recover
• 10-15% of mild TBI patients have symptoms at 1 year (called persistent post-concussive syndrome [PPCS])

Question 19

other causes of TBI

Answer 19

• epidural hematoma
• subdural hematoma

Question 20

treating hematoma

Answer 20

decompressive craniectomy
- remove portion of skull so brain can inflame and go out through that removed portion rather than pushing down inside the skull

Question 21

seizure

Answer 21

abnormal discharge of neurons that causes sudden and brief (seconds to minutes) abnormalities of brain function (sensory, motor, behavioral, cognitive)

Question 22

epilepsy

Answer 22

recurrent seizures of unknown etiology

Question 23

neurotransmitters in epilepsy

Answer 23

1) influx of sodium
2) influx of calcium
3) release of glutamate
4) activation of excitatory receptors
5) inhibition of GABAergic system

• thought that glutamate is implicated

Question 24

causes of seizures

Answer 24

• genetic
• trauma/brain injury
• tumors
• vascular - stroke, hemorrhage, AVM
• toxic - alcohol, cocaine
• infections - encephalitis, meningitis
• metabolic - hyponatremia, hypoglycemia, hypocalcemia
• other - sleep deprivation, fainting, fever (children)

Question 25

epilepsy - generalized

Answer 25

- tonic/clonic (Grand Mal) - absence (petit Mal) - complex partial (most common in adults) (unconscious)

Question 26

epilepsy - focal (partial)

Answer 26

simple partial (conscious)

Question 27

generalized tonic-clonic epilepsy

Answer 27

- impaired consciousness - aura (20%) --> feel that it is coming - collapse to floor - tonic body extension followed by clonic jerking - loss of bowel or bladder (20%) - prolonged post-ictal state up to hours

Question 28

petit mal seizures

Answer 28

- generalized (absence) - impaired consciousness, brief 2-3 second episodes - chewing movements in 20% of cases - NO post-ictal state; 3 per second spike-wave discharge

Question 29

complex partial seizures

Answer 29

- a focal onset impaired awareness seizure - starts in temporal lobe then moves to other areas of the brain that affect symptoms - impaired consciousness - dreamy state, deja vu - formed auditory hallucinations - music - formed visual hallucinations - chewing movements, automatisms (picking at clothing) - language disturbance

Question 30

simple partial (focal) seizures

Answer 30

- consciousness - somatosensory - tingling - motor - twitching, head turning, grimacing - visual - flashes of light - auditory - ringing, hisses, noises - olfactory - bad odors - autonomic - sweating, flushing, epigastric pain

Question 31

treatment of epilepsy

Answer 31

- anti-epileptic medications - surgery

Question 32

anti-epileptic medications

Answer 32

- decrease membrane excitability by interacting with neurotransmitter receptors or ion channels - act on sodium channels, gamma-aminobutyric acid (GABA) receptors, or calcium channels

Question 33

surgery to treat epilepsy

Answer 33

remove affected brain tissue

Question 34

types of brain tumors

Answer 34

primary, secondary

Question 35

primary brain tumors

Answer 35

- intraparenchymal --> glioma (astrocytoma) - extraparenchymal --> meningioma

Question 36

secondary brain tumors

Answer 36

intra or extraparenchymal --> metastases started outside the brain then traveled into the brain

Question 37

intraparenchymal

Answer 37

inside the brain

Question 38

extraparenchymal

Answer 38

outside the brain

Question 39

location of brain tumors

Answer 39

- adults: cerebral hemispheres - children: brainstem and cerebellum

Question 40

symptoms of brain tumors

Answer 40

- depends on location - slowly progressive - if cortex involved, seizures are common

Question 41

childhood brain tumors

Answer 41

- almost always in the posterior fossae: cerebellum and brainstem - balance (ataxia) and cranial nerve problems (double vision) typical - 4 types: 2 treatable, 2 not very treatable

Question 42

watershed zones

Answer 42

areas of the brain that are fed by two main artery supplies - the artery diameter is small and circulating tumors get stuck - metastasis often found at first in watershed zones

Question 43

usual sources of secondary tumors

Answer 43

- lung - colon - breast - melanoma - kidney