Nervous System Diagnostic Tests and Procedures Flashcards
Lumbar Puncture/ Tap
- introduction of needle to subarachnoid space (under arachnoid membrane) at level of L4 and L5 to withdraw CSF
- used to diagnose hemorrhage, CNS infection or obstruction of CSF flow
- EMLA or lidocaine cream used to limit pain 1 hr before procedure
Lumbar Puncture/ Tap Contraindications
- infected skin over needle insertion site
- suspected elevation of CSF pressure (pressure increase = less space) : might lead to cardiac arrest
Medulla Oblongata
respiratory center
Lumbar Puncture/ Tap Management
- instruct that they will feel pressure > pain
- after, encourage child to lie down for at least 30 mins and drink glass of fluid (prevent cerebral irritation caused by air rising in subarachnoid space)
- analgesics to be given when headache develop
- monitor WOF
Lumbar Puncture/ Tap WOF
- signs of intracranial compression
- decrease PR and RR
- change in LOC
- pupillary changes
- decrease in motor ability
Lumbar Puncture/ Tap Position
- lying
- sitting (if patient could move, sit and lean forward)
Ventricular Tap
- CSF obtained by subdural tap into a ventricle through anterior fontanelle
- px should be sedated
Ventricular Tap Position
semi fowlers (prevent additional drainage)
Anterior Fontanelle Closes at…
12-18 months
Posterior Fontanelle Closes at…
2 months
X-Ray Techniques
- flat skull x-ray film
- obtain information about increased ICP or skull defects (fracture, craniosynostosis, or premature knitting of cranial sutures)
- skull sutures appear separated = increased ICP
Cerebral Angiography
- x-ray study of cerebral blood vessels that involves injection of contrast medium into femoral or carotid artery
- taken as dye flows through blood vessels of cerebrum
Myelography
x-ray study of spinal cord following injection of contrast medium into the CSF through the lumbar puncture
Myelography Before the Procedure
ASSESS:
1. allergy to contrast medium
2. previous ingested medicine that may counteract contrast
Myelography After Procedure
keep head elevated (prevent contrast from reaching meninges surrounding the brain since it might cause irritation)
Computer Tomography (CT)
- use x-rays to reveal densities at multiple layers/ levels of brain tissues
- confirm presence of brain tumor or other encroaching lesions
Magnetic Resonance Imaging (MRI)
- uses magnetic field and computer generated radio waves to create details images of organs and tissues
- patient cannot move during the process
Positron Emission Tomography (PET)
- imaging after injection of positron-emitting radiopharmaceuticals into vein
- radioactive substances accumulate at diseased area of brain or spinal cord
- extremely accurate in identifying seizure foci
Echoencephalography (Ultrasound of Head/ Spinal)
- projection of ultrasound toward the child’s head or spinal cord
- non-invasive
- does not cause discomfort
- used to outline the ventricles of the brain
- monitor intraventricular hemorrhages on preterm infants
Electroencephalography (EEG)
- reflects electrical patterns of brain
- chemical and physical interactions within the brain at the time of test
- helpful in diagnosing absence seizures
- room will be darkened, child must be cooperative and extremely quiet during procedure
- sedation may be necessary for children who are unable to keep still
