Diagnostic tests

Question 1

Do increased cell counts of CSF correlate with severity of disease?

Answer 1

No - correlate with amount of exfoliation into CSF

Question 2

Relative to the lesion, where should CSF analysis be done - cranially or caudally?

Answer 2

Caudal to lesion

Question 3

What is the max volume of CSF that can be taken?

Can you aspirate when taking CSF analysis?

Answer 3

1ml/5kg (0.2ml/kg)

No!

Question 4

Give examples of when CSF analysis may be contraindicated

Answer 4

Increased intracranial pressure
Coagulopathy
Chiari like formation (if cervical collection)
AA stability
Cervical trauma

Question 5

How long after CSF collection should you do analysis?

Answer 5

Within 1 hr

Question 6

How should CSF appear grossly? How many RBCs and WBCs should be present?

Answer 6

Clear (cloudy suggests inflammation)
0 RBCs
<5 microleters

Question 7

Albuminocytological dissociation is an example of an abnormality that can be found on CSF analysis. What does albuminocytological dissociation mean?

Answer 7

Increased protein without increased WBCs

Question 8

What is pleocytosis?

Answer 8

Increased WBCs in CSF

Question 9

F-waves are a method of electrodiagnostics used to assess what?

Answer 9

Nerve routes

Question 10

Repetitive nerve stimulation is an electrodiagnostic test used to assess what?

Answer 10

NMJs

Question 11

Electroencephalography (EEG) is an electrodiagnostic test used to assess what?

Answer 11

Forebrain activity (e.g. status epileptics)

Question 12

Electromyography takes how long for results to become apparent? What can electromyography be used in conjunction with?

Answer 12

10-14 days

Used with muscle biopsies

Question 13

What test is used for junctionpathies?

Answer 13

Neostigmine response test

Question 14

What is the neostigmine test? What should you watch out for?

Answer 14

IV administration of neostigmine to assess junctionopathies
Cholinergic crisis (prolongs ACh at NMJ - bradycardia, salivation, tremors)

Question 15

The neostigmine response test can cause cholinergic crisis. What should always be prepared whilst doing this test?

Answer 15

Intubation kit

Atropine

Question 16

Nerve biopsies are most commonly taken from which nerve?

Answer 16

Peroneal

Can be any superficial, easily identified, mixed nerve

Question 17

Nerve biopsies are fixed in what solution?

Answer 17

Formalin

Keep nerve straight but not stretched

Question 18

What is myelography?

Answer 18

Injection of non-ionic, low osmolar positive contrast into subarachnoid space
(Radiopaque - used with CT or MRI - must take CSF first!)
Can be extradural (most common), intramural, intramedullay or extramedullary

Question 19

Give examples of when myelography may be contraindicated

Answer 19

Coagulopathies
Spinal instability
Cloudy/turbid CSF (as suggests inflammation)

Question 20

What are some complications of myelography?

Answer 20

Exacerbation of neurological signs
Seizures
Injection into brainstem
Central canologram
Spinal cord haematoma
Epidurogram
Rapid movement of contrast
Subdural injection (not a problem but not diagnostic)
Death