Neuro Intro LD

basic metabolic panel (BMP)

-kidney function and health

-blood glucose levels

-acid/base balance of blood

-fluid and electrolyte blance

glucose

blood sugar

70-115

calcium (Ca2+)

mineral critical to cardiovascular and nervous system bone health

sodium (Na+)

electrolyte

135-145

potassium (K+)

electrolyte

3.5-5

bicarbonate

electrolyte that helps measure CO2 in the blood

22-28

chloride (Cl-)

electroyte that works with K+, Na+, bicarbonate to facilitate proper water, electrolyte and acid base stats

95-105

blood urea nitrogen (BUN)

urea nitrogen is a protein breakdown product filtered out by the kidneys

7-18

-measures reabsorption of urea in kindeys

Creatinine (Cr)

creatinine is a waste material generated by normal muscle activity which is excreted through the glomerulus in kidneys

0.6-1.2

-measures how much creatinine in the blood is not being filtered out by kidneys

Glomerular Filtration Rate (GFR)

number of mL of the body fluid cleared by the kidneys per unit time

-low GFR= more waste retention

-renal function

-50% reduction of GFR = 2x creatinine

creatinine clearance

the rate of creatinine clearance by the kidneys

Complete Metabolic Panel (CMP)

BMP + Liver tests (ALP, ALT, AST, Bilirubin)

CT are used for

initial trauma evaluation/ bleeding

CT advantages

inexpensive, avaibale

exam in seconds

can be done when needed

patient can be brought in with anyhting

easy to interpret

CT disadvantage

use ionization radiation

can have unequal absorption of xrays

white matter can be seen poorly

poor resolution for lower cervical and thoracic spine

Intravenous contrast

iodinated nonionic water soluble

IV

circulated through body enters everywhere excpet within the CNS

Brain CT contraindications/precautions

claustrophobia (treated w meds)

obesity

pregnancy

unstable vitals

IV contrast dye: iodinated dye or shellfish allergy, contrast dye allergy, renal failure, glucophage

when to order CT of the brain

head trauma

acute severe headache

acute cerebral infarction

concern for neoplasm

concern for increased intracranial pressure

CT interpretation

denser tissue is brighter (hyperdense)

less dense is darker (hypodense)

bone is white, air is black

brain window- structures to be identified and differentiated

bone window- best for visualizing bone

when to use IV contrast

increase sensitivity

enhance normal and abnormal blood vessels

-aneurysms, vascular malformations, neoplasms

intravascular contrast material leaks into a lesion if the blood brain barrier is disrupted like infarction, abscess, neoplasms

white matter appears

blacker than grey matter because it has high content of myelinated axons and lower density

cytotoxic edema

loss of grey-white differentiation

-cant distinguish them from each other

vasogenic edema

accentuation of grey-white differentiation

-tumor or abscess

MRI

A noninvasive hydrogen atoms behave in magnetic field when disrupted by radiofrequency signals

contrast MRI

chelated gadolinium -safest

-renal patients at risk

-not for pregnant

MRI advantage

increased sensitivity and specificity

sagittal and coronal image obtained without changing patient

no ionizing radiation

chelated gadolinium is safe

excellent soft tissue resolution

MRI disadvantages

take a long time

claustrophobia

expensive

need to be screened for metallic material

when to order an MRI

stoke (follow up)

chronic headache

seizure

tumor

infection

demyelinating disease

spinal lesions

normal brain MRI

CT angiography (CTA) and MR angiography (MRA)

visualization of vasculature

look for aneurysms, stenosis, occlusion, dissection, vascular irregularities

MRA with or without contrast

CT venography (CTV) and MR venography (MRV)

visualization of veins and venous sinuses

evaluation of venous sinus thrombosis

CT angiography

-order when need to see blood vessels

3D images

safe

catheter angiography= gold standard

-can do noninvasively now

catheter-directed angiography

invasive, high risk procedure

small catheter in puncture of femoral artery > aorta > aortic arch > specific arteries > contrast material injected

gold standard= intracranial, extracranial, spinal vascular lesions

lumbar puncture

"spinal tap"

procedure of taking fluid from the spine in the lower back through a hollow needle

cerebrospinal fluid extracted

L3-L4 preferred because wider and has less soft tissue

lumbar puncture is diagnostic for

CNS infection (meningitis)

clinical concern for subarachnoid hemorrhage with a negative CT scan

lumbar puncture contraindications

infection at puncture site

acute spinal cord or head trauma

uncorrected severe coagulopathy

brain tumor

diffuse cerebral edema

lumbar puncture complication

brain herniation

headache

infection

spinal hematoma

neurologic compromise

ultrasound in lumbar puncture

reduces risk of failed or traumatic procedure, number of needle insertions

cerebrospinal fluid analysis

routine analysis: clear vs cloudy vs purulent), cell type, number of cells, glucose, total protein

gram stain and culture

can be tested by cytology

normal CSF

clear and colorless, acellular

electroencephalogram (EEG)

used for paroxysmal neurological disorders like seizures and epilepsy

uses amplification of brain electrical activity

spatial and temporal information

EEG test

electrodes on head

over 30 min period

EEG interpretation

montages: comparison of recordings from individual electrodes

interictal and ictal data are used to classify and diagnose seizures types, epilepsy disorders

EEG when to order

suspected seizure

classify seizure and epilepsy

management of epilepticus

evaluation of altered mental status

monitor things

-normal EEG does not exclude the possibility of epilepsy and seizures

Continuous EEG Monitoring

with or without simultaneous video monitoring

gold standard= concurrent video and EEG monitoring for diagnosis of seizures, epilepsy, psychogenic nonepileptic seizures

Electromyography (EMG) and nerve conduction studies (NSC)

motor and sensory conduction studies can be used to identify focal lesions and distinguish peripheral neuropathy from myopathy and motor neuron diseases

EMG and NSC functions

localization of symptoms

distinction between axonal and demyelinating neuropathies

distinction between disease of nerve and muscle

diagnosis of disease

NCS

nerves are electrically stimulated through the skin using electrodes

if motor nerve is stimulated: compound muscle (or motor) action potential (CMAP)

if sensory nerve is stimulated: sensory nerve action potential (SNAP)

EMG

activity of individual muscles

muscle response

small needles in the skin, electrical activity is picked up as muscle is stimulated

-measures at rest, contraction of muscles