Neurophysiology

Question 1

Normal sleep latency in adults

Answer 1

15-20 minutes

Question 2

Which stages of sleep are slow wave?

Answer 2

3 and 4 (slow delta waves predominate in those stages)

Question 3

When is there a nocturnal surge of growth hormone?

Answer 3

Stage 3 and 4 of NREM sleep

Question 4

What inhibits growth hormone?

Answer 4

Somatostatin

Question 5

When is the normal dominant alpha rhythm achieved?

Answer 5

12-14 years

Question 6

Where is the dominant alpha rhythm seen?

Answer 6

Posteriorly in the occipito-parietal region

Question 7

What can abolish the dominant alpha rhythm?

Answer 7

Opening eyes
Concentrating
Arousal state
Anxiety

Question 8

Ongoing ___ rhythm is almost always abnormal in adults

Answer 8

Delta

Question 9

What happens to EEG after ECT?

Answer 9

EEG immediately shows delta and theta excess but then returns to normal levels after 3 months of the end of treatment

Question 10

What changes to receptors happens after ECT?

Answer 10

Reduced beta receptors

Question 11

EEG changes in Angelman syndrome

Answer 11

Noted by age of 2 - prolonged runs of high amplitude 2-3Hz frontal activity

Question 12

What does EEG of patient with absence seizures show?

Answer 12

Regular 3Hz complexes

Question 13

Sleep changes with benzo on EEG

Answer 13

1. Decreased sleep latency
2. Increased sleep time
3. Reduced stage 1 sleep
4. Increased stage 2 sleep

Question 14

What happens to melatonin during REM sleep?

Answer 14

Decreases

Question 15

Which ion is freely permeable across cell membranes?

Answer 15

Chloride

Question 16

Alpha wave frequency

Answer 16

8-13Hz

Question 17

Beta wave frequency

Answer 17

13-40Hz

Question 18

Theta wave frequency

Answer 18

4-8Hz

Question 19

Delta wave frequency

Answer 19

Less than 4Hz

Question 20

What is the dominant rhythm of infants on EEG?

Answer 20

3Hz - dominant delta and theta waves

Question 21

Which stimulant does not cause REM rebound?

Answer 21

Modafinil

Question 22

EEG finding in CJD

Answer 22

Generalised 1-2Hz bi or triphasic sharp and slow-wave complexes

(Earliest EEG finding is more often rhythmic generalised slowing)

Question 23

EEG hepatic encephalopathy

Answer 23

Triphasic wave

Question 24

Which stage of sleep do you see K-complexes in?

Answer 24

Stage 2

Question 25

EEG finding in antipsychotics

Answer 25

Slowing of beta activity | Increase in alpha, theta and delta

Question 26

Which sleep phase dominates in neonate?

Answer 26

REM

Question 27

Orexin neurons are dysfunctional in which disorder?

Answer 27

Narcolepsy

Question 28

EEG in sub acute sclerosing panencephalitis

Answer 28

High amplitude, repetitive bilaterally synchornic symmetrical polyphasic sharp wave and slow wave complexes which occur every 4 to 15 seconds

Question 29

Which area of the brain when stimulated via magnetic pulse reduces depression?

Answer 29

Left prefrontal

Question 30

What % of people with epilepsy will have normal EEG between attacks?

Answer 30

30-50%

Question 31

Stimulation of which receptor leads to sleep onset?

Answer 31

Cholinergic receptors

Question 32

Which wave is prominent when eyes are closed but patient is not sleeping?

Answer 32

Alpha

Question 33

What effect do antidepressants have on EEG?

Answer 33

Slow beta | Increase theta and delta

Question 34

EEG in generalised seizures

Answer 34

Generalised spike-wave discharges

Question 35

Which condition is associated with low cortisol?

Answer 35

PTSD

Question 36

Where is the highest concentration of serotonin found?

Answer 36

In the pineal gland

Question 37

What is melatonin synthesised from?

Answer 37

Serotonin

Question 38

How is melatonin synthesised from serotonin?

Answer 38

By serotonin-N-acetylase and 5 hydroxyindole-O-methyltransferase

Question 39

Effect of propranolol on melatonin synthesis

Answer 39

Pineal gland regulated by beta-adrenergic mechanism - beta-antagonists such as propranolol decrease melatonin synthesis

Question 40

What hormone is increased at start of sleep?

Answer 40

Testosterone

Question 41

Which hormones are increased during slow wave sleep?

Answer 41

GH and SST

Question 42

Which hormone is decreased during slow wave sleep?

Answer 42

Cortisol

Question 43

What is the sleep switch nucleus?

Answer 43

Ventrolateral preoptic nucleus

Question 44

What does the ventrolateral preoptic nucleus do?

Answer 44

Induces sleep by putting brakes on arousal nuclei

Question 45

What are REM-ON neurons?

Answer 45

Cholinergic

Question 46

What are REM-OFF neurons?

Answer 46

Noradrenergic

Question 47

Which sleep stage increases in anxiety?

Answer 47

Stage 1 (light sleep)

Question 48

What causes early morning wakening in depression?

Answer 48

Increased REM sleep

Question 49

What is a lambda wave?

Answer 49

Single occipital, triangular wave produced by visual scanning when awake e.g. reading