Neurophysiology

Question 1

Investigating muscle and nerves

Answer 1

NCS: sensory function

Question 2

How does it work

Answer 2

• electrical stimulation makes the outside of the nerve negative
• inside is thus positive by comparison: triggers an A.P which moves down the nerve
• record this with sticky electrodes
• measure size of response and its speed

Question 3

What is NCS used for

Answer 3

Entrapments

Question 4

EMG

Answer 4

• records activity of motor units

Question 5

Myasthenia Gravis

Answer 5

Affects postsynaptic neurons

Question 6

How do we investigate the brain

Answer 6

EEGs

• mainly for patients with seizures
• electrodes placed in specific locations on the scalp

Question 7

What is an intra-cranial EEG

Answer 7

• Used in patients being worked up for epilepsy surgery

Question 8

Frontal lobe seizure

Answer 8

• brief

- fencing posture

Question 9

Gyratory seizures

Answer 9

• rotastes body around at 180 degrees

Question 10

Somatosensory evoked potentials

Answer 10

Looks at the integrity of dorsal columns. Stimulate peripheral nerves

Question 11

Main uses

Answer 11

1. ) MS

2. ) Intra-operative monitoring e.g. spinal cord surgery

Question 12

Visual evoked potentials

Answer 12

Looking at visual pathways

Question 13

Transcranial magnetic stimulation

Answer 13

Record time it takes for magnetic potential to reach muscle