3- Neuro Diagnostic Studies Flashcards
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?
Electroencephalogram (EEG)
What are the indications for an EEG? (4)
Seizure disorders
Metabolic encephalopathy (focal vs generalized slowing)
Cortical (neglect, aphasia, hemianopia) vs subcortical (motor hemiparesis)
Tumors (focal/ spiked discharges)
What EEG rhythm represents a normal awake adult?
8-12 Hz (alpha)
Are there any major contraindications to EEG?
No
What neuro imaging differentiates primary muscle conditions from muscle weakness caused by neurologic disorders by measuring the electrical activity of muscle fibers/ motor unit?
Electromyogram (EMG)
What are the indications for an EMG? (4)
Lower motor neuron disease (ALS)
NMJ disease (Myasthenia gravis) - fatigability
Muscle disease (myopathy) - decreased amplitude of motor response
Peripheral nerve disorders
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)
Nerve conduction studies
What are the indications for nerve conduction studies? (5)
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)
What are the indications for plain spine films in neuroimaging? (3)
Degenerative disease
Trauma
Malignancy
What neuroimaging should be ordered for a pt with spondylolisthesis?
Lumbar spine films
(flexion/ extension views)
What is first line imaging to look for fractures with or w/o associated complications?
Plain films
(followed by CT/ MRI for soft tissue involvement)
What are the indications for plain skull films? (3)
Trauma
Metabolic disease
Malignancy
What are the indications for CT head? (5)
Trauma
Stroke
Hydrocephalus
Suspicious HAs
AMS
(Spine = trauma, degenerative)
Pt presents with loss of consciousness. What do you order?
CT scan
Pt presents with persistent neurologic dysfunction. What do you order?
CT scan
Pt presents with persistent vomiting. What do you order?
CT scan
Pt presents with GCS < 8 or deteriorating. What do you order?
CT scan
Pt presents with retrograde or anterograde amnesia. What do you order?
CT scan
Pt presents with post-traumatic seizures. What do you order?
CT scan
CT scan shows lens-shaped hematoma. Where do you suspect the location of the bleed is?
Epidural
(between dura and skull)
CT scan shows cresent-shaped hematoma. Where do you suspect the location of the bleed is?
Subdural
(between dura and arachnoid)
Eval of a pt leads to suspicion of a hemorrhagic stroke (TIA/ CVA). What neuroimaging must be ordered prior to administration of thrombolytic meds?
Non-contrast head CT
MRI if CT (-) and/ or brainstem/ cerebellar CVA or mass suspected
What are the indications for an MRI? (5)
Tumors
Vascular disease
Inflammation/ infection
MS
Degenerative disease (spinal cord)
T1 MRI imaging reflects uptake (dark) of magnetic energy making it better for normal anatomy or pathology?
Normal anatomy
T2 MRI imaging reflects release (white) of magnetic energy making it better for normal anatomy or pathology?
Pathology
What is the diagnostic study of choice for brain tumors?
MRI with gadolinium
(mass effect, surrounding edema, pattern of enhancement)
What is the most sensitive test when you suspect an acute ischemic stroke of the brain or spinal cord?
Diffusion MR
(also helpful in work up for encephalitis/ abscess)
On brain MRI you note periventricular plaques. What disease are you concerned for?
MS
Pt presents with new onset neuro sxs. What is the recommended imaging?
CT
MRI if CT (-) and pt has neuro deficit
Pt presents with dizziness and you suspect brainstem/ cerebellar CVA or mass. What neuroimaging should be ordered?
MRI
(CT if mod clinical suspicion)
Pt presents with HA. What neuroimaging should be ordered?
CT if mod clinical suspicion
MRI if high clinical suspicion
What are the indications for MRI spine? (6)
Radiculopathy
High impact trauma
New/ progressive deficit
Tumor/ infection
Neuro claudication
New onset back pain in CA pt
What neuroimaging study is used to assess degree of blood vessel stenosis?
Carotid US
(degree of stenosis determines treatment)
What neuroimaging is indicated when definitive anatomy is needed? (ex. pre-op for CEA or aneurysm repair)
Angiography (with IV contrast)
What study should be performed to evaluate for meningitis?
Lumbar puncture
(obtain CSF sample for analysis)
When should a lumbar puncture NOT be performed?
Papilledema/ increased ICP
