neurological disorders Flashcards
CT B/H indications
when CNS disease is suspected
useful for dx brain tumors, infarctions, bleeding, hematoma, and degenerative abnormalities
consider CT B/H when pt presents with
- new onset headache
- “blinding HA”, where part of vision is impaired
- unilateral headache
- cranial nerve neuropathy
- after head trauma, falls
CT B/H with contrast does what
vascular structures enhanced
CI to CT B/H
- allergy to iodine or shellfish
- claustrophobic
- pregnancy, unless benefit outweighs risk , ie trauma
- unstable VS
- morbidly obese, CT scanner usually < 300 lb
CT required if any 1 of following are present after TRAUMA
- GCS < 15 at 2 hr after injury
- suspected open or depressed skull fx (hemotympanum, racoon eyes, cerebrospinal otorrhea, rhinorrhea, or Battle’s sign)
- 2 or more episodes of vomiting
- > 65 y/o
- amnesia of events more than 30 minutes before impact
- post trauma seizures
- known coagulopathy; clotting disorders, on blood thinners
why is CT B/H ideal for initial trauma
bc can be down in short time, usually less than 10 minutes
can accommodate pts on life support or needed other equipment
what is hemotympanium
presence of blood in tympanic membrane of middle ear
battle’s sign aka mastoid ecchymosis
suggests underlying brain trauma
indication of fx along middle cranial fossa of skull
commonly seen after basilar skull fx
what is periorbital ecchymosis
aka raccoon eyes
discoloration of upper and lower eyelids
most concerning for trauma
most associated with basal skull fx
CT brain/head complications
- allergic reaction to IV dye
- contrast induced nephropathy
- lactic acidosis
pts at risk for contrast induced nephropathy
elevated serum Cr, dehydration at time of contrast, CHF, age > 70 yrs, use of nephrotic drugs- NSAIDS, diuretics, ace-i
contrast for MRI is what
gadolinium
less likely to cause allergic reaction when compared to iodine based dye
nephrotic systemic fibrosis is what
reaction from gadolinium
thickening of skin and other organs
rare complication in pts with severe kidney disease
MRI indications
- brain tumors
- developmental anomalies of brain
- vascular anomalies of head- aneurysms
- disorders of eyes and inner ear
- CVA f/u
- trauma pts- post CT
- disease in pituitary gland
- certain chronic disorders of nervous system, ie ms
- causes of HA
what does EEG do
ectroencephalogram
records electrical activity of brain by placing electrodes on skull
recordings made with pt awake and sometimes asleep
also used to dx brain death when considering dc life support
positive EEG confirms what
seizure
EMG does what
electromyogram or electromyography
records electrical impulses in muscle at rest
how are EMGs performed
needle electrode is inserted into muscle to record electrical activity- ouchy
emg are used for what
dx and assess capacity of muscles to fx normally
helpful for dx metabolic disorders of muscle and nm disorders affecting skeletal muscles (GBS, myasthenia gravis, MS, muscular dystrophy, diabetic neuropathy)
what happens in abnormal EMGs
tests abnormal when nerve supply to muscle has been compromised
indicative of nerve conduction blockage
nerve conduction study aka electroneurogram -ENG- is what
small electrical current activated through an electrode near a nerve
time the impulse takes to get from first to second electrode is the conduction velocity
EMG vs ENG
EMG measures electrical activity of muscle at rest
ENG measures how well and fast nerve can send electrical impulses
often done together
ENG is used to assess what
capability of nerves to conduct impulses
metabolic and physical damage to nerve alter the ability
seen in carpal tunnel, herniated spinal disc, diabetic neuropathy
how to dx carpal tunnel
clinical grounds
ENG can assist
ENG not always necessary for other indications
- herniated disc pinching a nerve
2. dm neuropathy
PET scan helps distinguish what
between living and dead tissue or between benign and malignant disorders
can help detect functional abnormalities early in course of disease, before anatomical changes occur
clinical significance of PET scans with CVAs
might show metabolically active tissue- may influence prognosis/tx plan
pet scan indications
- cva
- epilepsy
- parkinsons
- alzheimers
- dementia
- tumor
- huntington’s
