3- Neuro Diagnostic Studies

Question 1

What neuro imaging is a safe, painless recording of the cortical electrical activity, can be used while awake or asleep and may be affected by stressors such as sleep deprivation or hyperventilation?

Answer 1

Electroencephalogram (EEG)

Question 2

What are the indications for an EEG? (4)

Answer 2

Seizure disorders

Metabolic encephalopathy (focal vs generalized slowing)

Cortical (neglect, aphasia, hemianopia) vs subcortical (motor hemiparesis)

Tumors (focal/ spiked discharges)

Question 3

What EEG rhythm represents a normal awake adult?

Answer 3

8-12 Hz (alpha)

Question 4

Are there any major contraindications to EEG?

Answer 4

No

Question 5

What neuro imaging differentiates primary muscle conditions from muscle weakness caused by neurologic disorders by measuring the electrical activity of muscle fibers/ motor unit?

Answer 5

Electromyogram (EMG)

Question 6

What are the indications for an EMG? (4)

Answer 6

Lower motor neuron disease (ALS)

NMJ disease (Myasthenia gravis) - fatigability

Muscle disease (myopathy) - decreased amplitude of motor response

Peripheral nerve disorders

Question 7

What neuro imaging is used to assess the rate of conduction and the amplitude of response of peripheral neves, and is usually performed in conjunction with an EMG?

(how well and how fast the nerves can send signals)

Answer 7

Nerve conduction studies

Question 8

What are the indications for nerve conduction studies? (5)

Answer 8

Differentiate between primary nerve vs muscle disorders

Differentiate LMN diseases from peripheral neuropathy

Abns in sensory nerves

Axonopathy (decreased amplitude)

Demyelinating process (decreased conduction rate)

Question 9

What are the indications for plain spine films in neuroimaging? (3)

Answer 9

Degenerative disease

Trauma

Malignancy

Question 10

What neuroimaging should be ordered for a pt with spondylolisthesis?

Answer 10

Lumbar spine films

(flexion/ extension views)

Question 11

What is first line imaging to look for fractures with or w/o associated complications?

Answer 11

Plain films

(followed by CT/ MRI for soft tissue involvement)

Question 12

What are the indications for plain skull films? (3)

Answer 12

Trauma

Metabolic disease

Malignancy

Question 13

What are the indications for CT head? (5)

Answer 13

Trauma

Stroke

Hydrocephalus

Suspicious HAs

AMS

(Spine = trauma, degenerative)

Question 14

Pt presents with loss of consciousness. What do you order?

Answer 14

CT scan

Question 15

Pt presents with persistent neurologic dysfunction. What do you order?

Answer 15

CT scan

Question 16

Pt presents with persistent vomiting. What do you order?

Answer 16

CT scan

Question 17

Pt presents with GCS < 8 or deteriorating. What do you order?

Answer 17

CT scan

Question 18

Pt presents with retrograde or anterograde amnesia. What do you order?

Answer 18

CT scan

Question 19

Pt presents with post-traumatic seizures. What do you order?

Answer 19

CT scan

Question 20

CT scan shows lens-shaped hematoma. Where do you suspect the location of the bleed is?

Answer 20

Epidural

(between dura and skull)

Question 21

CT scan shows cresent-shaped hematoma. Where do you suspect the location of the bleed is?

Answer 21

Subdural

(between dura and arachnoid)

Question 22

Eval of a pt leads to suspicion of a hemorrhagic stroke (TIA/ CVA). What neuroimaging must be ordered prior to administration of thrombolytic meds?

Answer 22

Non-contrast head CT

MRI if CT (-) and/ or brainstem/ cerebellar CVA or mass suspected

Question 23

What are the indications for an MRI? (5)

Answer 23

Tumors

Vascular disease

Inflammation/ infection

MS

Degenerative disease (spinal cord)

Question 24

T1 MRI imaging reflects uptake (dark) of magnetic energy making it better for normal anatomy or pathology?

Answer 24

Normal anatomy

Question 25

T2 MRI imaging reflects release (white) of magnetic energy making it better for normal anatomy or pathology?

Answer 25

Pathology

Question 26

What is the diagnostic study of choice for brain tumors?

Answer 26

MRI with gadolinium

(mass effect, surrounding edema, pattern of enhancement)

Question 27

What is the most sensitive test when you suspect an acute ischemic stroke of the brain or spinal cord?

Answer 27

Diffusion MR

(also helpful in work up for encephalitis/ abscess)

Question 28

On brain MRI you note periventricular plaques. What disease are you concerned for?

Answer 28

MS

Question 29

Pt presents with new onset neuro sxs. What is the recommended imaging?

Answer 29

CT

MRI if CT (-) and pt has neuro deficit

Question 30

Pt presents with dizziness and you suspect brainstem/ cerebellar CVA or mass. What neuroimaging should be ordered?

Answer 30

MRI

(CT if mod clinical suspicion)

Question 31

Pt presents with HA. What neuroimaging should be ordered?

Answer 31

CT if mod clinical suspicion

MRI if high clinical suspicion

Question 32

What are the indications for MRI spine? (6)

Answer 32

Radiculopathy

High impact trauma

New/ progressive deficit

Tumor/ infection

Neuro claudication

New onset back pain in CA pt

Question 33

What neuroimaging study is used to assess degree of blood vessel stenosis?

Answer 33

Carotid US

(degree of stenosis determines treatment)

Question 34

What neuroimaging is indicated when definitive anatomy is needed? (ex. pre-op for CEA or aneurysm repair)

Answer 34

Angiography (with IV contrast)

Question 35

What study should be performed to evaluate for meningitis?

Answer 35

Lumbar puncture

(obtain CSF sample for analysis)

Question 36

When should a lumbar puncture NOT be performed?

Answer 36

Papilledema/ increased ICP