8- Consciousness

Question 1

Consciousness requires which two neural components functioning normally and being connected to eachother?

Answer 1

Cerebral cortex and reticular formation

Question 2

What effects do the cerebral cortex and reticular formation have on each other?

Answer 2

They both exert an excitatory effect on each other forming a positive feedback loop

Question 3

The reticular send cholinergic projections to which 3 structures of the brain?

Answer 3

Basal forebrain nuclei, hypothalamus, thalamus

Question 4

What type of neurones project from the basal forebrain nuclei to the cortex as part of the positive feedback loop of reticular formation and cortex?

Answer 4

Cholinergic (excitatory)

Question 5

What type of neurones project from the hypothalamus to the cortex as part of the positive feedback loop of reticular formation and cortex?

Answer 5

Histaminergic (excitatory)

Question 6

What type of neurones project from the thalamus to the cortex as part of the positive feedback loop of reticular formation and cortex?

Answer 6

Glutamatergic (excitatory)

Question 7

What is most commonly used to assess a patients level of consciousness?

Answer 7

The Glasgow coma scale (GCS)

Question 8

What components are you looking at in the GCS?

Answer 8

Eye opening, motor responses and verbal responses

Question 9

If a patient only open their eyes to pain, withdraws to pain and makes incomprehensible sounds which parts of brain may still be intact?

Answer 9

Cortical damage but brain stem preserved

Question 10

What are the different levels for eye opening in GCS?

Answer 10

Spontaneously looking around, response to speech, response to pain, no response

Question 11

What are the different levels associated with motor responses in the GCS?

Answer 11

Obey commands, localises to stimuli, withdraws to pain, flexor reflex, extensors reflex, no response

Question 12

If a patient has a flexor response to pain what does this suggest about site of a lesion?

Answer 12

Suggests lesion above the level of the red nuclei

Question 13

What are the levels of verbal response in the GCS?

Answer 13

Appropriate response to question, confused conversation, inappropriate words, incomprehensible sounds, no response

Question 14

What type of waves are seen on an electroencephalogram when a subject is awake with eyes closed and eyes open?

Answer 14

Eyes open- beta waves

Eyes closed- alpha waves (slower frequency)

Question 15

What is sleep apnoea?

Answer 15

A common condition where there is compression of the airways during sleep causing frequent waking