Arousal, Coma and Unconciousness

Question 1

define arousal

Answer 1

state of wakefulness

Question 2

define consciousness

Answer 2

arousal + context

- awareness of both self and the external environment determined by a motor response to internal or external stimulus

Question 3

define coma

Answer 3

total absence of awareness of both self and external environment
- severest impairment of arousal
- inability to obey commands, speak, open eyes to pain
GCS 3-8

Question 4

What are the three components of GCS?

Answer 4

Eye opening
Best Verbal Response
Best Motor Response

Question 5

What is the highest and lowest GCS score?

Answer 5

• lowest = 3

- highest = 15

Question 6

What are the subdivisions of eye opening?

Answer 6

1 = none 
2 = to pain 
3 = to speech 
4 = spontaneous

Question 7

What are the subdivisions of best verbal response?

Answer 7

1 = none 
2 = incomprehensible sounds
3 = inaapropriate 
4 = confused 
5 = oriented

Question 8

What are the subdivision of best motor response?

Answer 8

1 = none 
2 = extension 
3 = abnormal flexion 
4 = flexion to pain 
5 = localises to pain 
6 = obeys commands

Question 9

What is the anatomy underlying coma?

Answer 9

• both cerebral hemispheres and/or brain stem ascending reticular activating system is grossly impaired

Question 10

What is required for arousal and awareness?

What is required for cognition and consciousness?

Answer 10

• functioning reticular activating system

- intact cerebral cortex

Question 11

What is the main component of the ascending reticular activating system (ARAS)?
What are its inputs?
What are its outputs?

Answer 11

• central tegmental tract
  Inputs = vestibular nuclei, ascending pain pathways. If upside down or in pain –> wake up
  Outputs = to hypothalamus thalamus and hence cerebral cortex

Question 12

Where does ARAS extend to and from?

Answer 12

Extends from caudal medulla to rostral midbrain

Question 13

What is required of the cerebral hemispheres to result in coma with an intact brainstem?

Answer 13

• widespread dysfunction of both hemispheres

- often drugs

Question 14

Give examples of acute altered status of conciousness

Answer 14

• clouding of consciousness = attention lack, slow thinking, confusion, memory loss, drowsiness
• delirium = + disorientation and hallucination
• stupor = sleep-like state

Question 15

Give examples of chronic altered state of conciousness

Answer 15

• dementia = mental function, memory, comprehension, speech
• hypersomnia excessive drowsiness and intermittent wakening
• vegetative state = after TBI, no evidence of concious intelligence

Question 16

What are the causes of coma?

Answer 16

• lesions causing diffuse brain dysfunction
• supratentorial mass lesions causing BS compression
• infratentorial lesino causing BS compression
• intrinsic lesions of BS itself
• psychiatric states that may mimic comatosed states

Question 17

What GCS define coma?

Answer 17

1-8

Question 18

Describe the oculocephalic reflex when concious and unconscious

Answer 18

• conscious - eyes move with head as its rotated

- unconcious - eyes remain in original position, slowly rotate to new mid position

Question 19

What is the oculovestibular reflex/caloric stimulation

Answer 19

• put cold water into ear

- eyes should move the that side

Question 20

What is the abnormality in decorticate response?

Answer 20

Hemisphereic dysfunction –> abnormal Flexion of arms

extension of legs

Question 21

What is the abnormality in decerebrate response?

Answer 21

Decorticate by to upper brains the

–> abnormal extension of arm and leg

Question 22

What is abnormality in flaccidity?

Answer 22

• pontine medullary damage

Question 23

What pattern of breathing do those locked-in show?

Why?

Answer 23

• patient breathing automatically

- not corticospinal tract to adjust

Question 24

What pattern of breathing do those with ondines curse show?

Answer 24

• can be voluntarily but will stop or hypoventiliate when asleep