Neuro Exam 1: Neuro Investigations

Front 1

What are the most commonly performed neuro tests?

Back 1

1. Lumbar puncture
2. CT (head/neck)
3. MRI (brain/cord)
4. EMG/PNCV
5. EEG

Front 2

Where is the CSF (what space)?

Back 2

subarachnoid

Front 3

Where do you commonly do an LP?

Back 3

L2-L3 or L3-L4

Front 4

What is the function of the choroid plexus?

Back 4

produce CSF

Front 5

What is the function of the arachnoid villi?

Back 5

absorb CSF into venous system

Front 6

What makes up the blood-CSF barrier?

Back 6

choroid

Front 7

Where are the majority of the arachnoid villi?

Back 7

superior saggital sinus

Front 8

Through what does CSF flow b/w the 3rd and 4th ventricles?

Back 8

aqueduct of Sylvius

Front 9

Through what does CSF flow b/w the lateral and 3rd ventricles?

Back 9

Foramen of Monro

Front 10

When is LP indicated?

Back 10

1. suspected meningitis
2. suspected subarachnoid hemorrhage
3. suspected MS
4. suspected Guillain-Barre Syndrome
5. suspected carcinomatous meningitis
6. relief and dx of intracranial HTN

Front 11

What are some contraindications of an LP?

Back 11

1. infected skin over needle entry site
2. severe coagulopathy
3. risk of herniation

Front 12

How do you determine risk of herniation?

Back 12

IMAGING! Look for:
midline shift, loss of cisterns, posterior fossa mass

Front 13

Appearance: Normal CSF

Back 13

clear and colourless

Front 14

Appearance of CSF: bacterial meningitis

Back 14

cloudy and turbid (if severe)

Front 15

Appearance of CSF: Viral/asceptic meningitis

Back 15

clear

Front 16

Appearance of CSF: Tuberculous meningitis

Back 16

Clear or slightly cloudy. may have cobweb appearance

Front 17

Appearance of CSF: Subarachnoid hemorrhage

Back 17

blood-stained (not always)

Front 18

Low CSF glucose. What you thinking?

Back 18

bacterial meningitis, tuberculous meningitis, maybe subarachnoid hemmorhage

Front 19

CSF Cell Count: bacterial meningitis

Back 19

High and mostly PMNs

Front 20

Opening pressure: Bacterial meningitis

Back 20

high

Front 21

CSF Protein: Bacterial meningitis

Back 21

raised > 1.5 g/l

Front 22

what is the main thing that differentiates viral meningitis from normal CSF?

Back 22

viral will have high WBCs (lymphocytes)

Front 23

what is xanthochromia?

Back 23

blood breakdown products in the CSF making it look yellow

Front 24

how can you tell tubercular from bacterial meningitis?

Back 24

gram stain

Front 25

What is normal CSF glucose?

Back 25

60-80% of plasma glucose

Front 26

oligoclonal bands in CSF. what you thinking?

Back 26

MS

Front 27

what is CSF protein in Guillian-Barre?

Back 27

elevated

Front 28

Why do you routinely do a head CT?

Back 28

stroke, head injury, rapid decline in mental status

Front 29

If you need to image the spinal cord, what modality will you use?

Back 29

MRI

Front 30

When would you routinely do an MRI?

Back 30

concern for tumor, infection, MS, etc.

Front 31

When is contrast especially useful?

Back 31

tumor and abscesses

Front 32

when is contrast (CT and MRI) contraindicated?

Back 32

renal failure

Front 33

CT or MRI: r/o hydrocephalus?

Back 33

CT

Front 34

CT or MRI: r/o mass effect

Back 34

CT

Front 35

CT or MRI: r/o spinal cord compression

Back 35

MRI

Front 36

What does a compound sensory nerve action potential (SNAP) tell you?

Back 36

you zap a nerve w/ some known current and measure how much current is delivered distally

Front 37

Simply describe EMG

Back 37

electrode placed directly into a muscle. record discharges at rest (spontaneous) and when using muscle

Front 38

What does the amplitude of an EMG tell you?

Back 38

how well the axon is working

Front 39

What does the conduction velocity of an EMG tell you?

Back 39

how well the myelin is working

Front 40

What are compound muscle APs?

Back 40

summation of APs of all muscle fibers

Front 41

What is a motor unit?

Back 41

single alpha motor neuron and all of the muscle fibers that it innervates

Front 42

What is a motor unit potential (MUP)?

Back 42

AP generated when an individual motor unit fires.

Front 43

What are EMGs useful for telling you (big picture)

Back 43

if muscle has lost its nerve, or if the muscle itself is messed up.

Front 44

When is an EMG indicated?

Back 44

pts w/ weakness or numbness in which the localization and etiology are unclear (ALS, MG, compression mononeuropathies, etc.)

Front 45

When are EMGs contraindicated?

Back 45

pts w/ increased bleeding risk or when it is unnecessary

Front 46

When are EEGs most useful?

Back 46

epilepsy (esp. during a seisure)

Front 47

T or F: normal EEG can r/o epilepsy

Back 47

False! Normal EEGs don't r/o anything

Front 48

Abnormal EEG w/ diffuse slowing. What are you thinking?

Back 48

encephalopathy

Front 49

What are evoked potentials?

Back 49

used during spinal surgery to measure limb innervation

Front 50

What is a polysomnogram?

Back 50

derivative of EEG useful for identifying sleep disorders

Front 51

When do you have beta waves on EEG?

Back 51

conciously alert/agitated (they are normal)

Front 52

When do you see alpha waves on EEG?

Back 52

physical and mental relaxation, although aware (normal)

Front 53

when do you see theta waves on EEG?

Back 53

somnolence w/ reduced consciousness

Front 54

When do you see delta waves on EEG?

Back 54

unconciousness or deep sleep

Front 55

Name the wave: 13-60Hz

Back 55

beta

Front 56

Name the wave: 7-13Hz

Back 56

alpha

Front 57

Name the wave: 4-7Hz

Back 57

theta

Front 58

Name the wave: 0.1-4Hz

Back 58

delta