Nervous System Diagnostic Tests and Procedures

Question 1

Lumbar Puncture/ Tap

Answer 1

• 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

Question 2

Lumbar Puncture/ Tap Contraindications

Answer 2

1. infected skin over needle insertion site
2. suspected elevation of CSF pressure (pressure increase = less space) : might lead to cardiac arrest

Question 3

Medulla Oblongata

Answer 3

respiratory center

Question 4

Lumbar Puncture/ Tap Management

Answer 4

• 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

Question 5

Lumbar Puncture/ Tap WOF

Answer 5

1. signs of intracranial compression
2. decrease PR and RR
3. change in LOC
4. pupillary changes
5. decrease in motor ability

Question 6

Lumbar Puncture/ Tap Position

Answer 6

1. lying
2. sitting (if patient could move, sit and lean forward)

Question 7

Ventricular Tap

Answer 7

• CSF obtained by subdural tap into a ventricle through anterior fontanelle
• px should be sedated

Question 8

Ventricular Tap Position

Answer 8

semi fowlers (prevent additional drainage)

Question 9

Anterior Fontanelle Closes at…

Answer 9

12-18 months

Question 10

Posterior Fontanelle Closes at…

Answer 10

2 months

Question 11

X-Ray Techniques

Answer 11

• 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

Question 12

Cerebral Angiography

Answer 12

• 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

Question 13

Myelography

Answer 13

x-ray study of spinal cord following injection of contrast medium into the CSF through the lumbar puncture

Question 14

Myelography Before the Procedure

Answer 14

ASSESS:
1. allergy to contrast medium
2. previous ingested medicine that may counteract contrast

Question 15

Myelography After Procedure

Answer 15

keep head elevated (prevent contrast from reaching meninges surrounding the brain since it might cause irritation)

Question 16

Computer Tomography (CT)

Answer 16

• use x-rays to reveal densities at multiple layers/ levels of brain tissues
• confirm presence of brain tumor or other encroaching lesions

Question 17

Magnetic Resonance Imaging (MRI)

Answer 17

• uses magnetic field and computer generated radio waves to create details images of organs and tissues
• patient cannot move during the process

Question 18

Positron Emission Tomography (PET)

Answer 18

• 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

Question 19

Echoencephalography (Ultrasound of Head/ Spinal)

Answer 19

• 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

Question 20

Electroencephalography (EEG)

Answer 20

• 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