2. LUMBAR PUNCTURE or SPINAL TAP is carried
out by inserting a needle into Lumbar
subarachnoid space to withdraw C S F
3. To obtain C S F for analysis & diagnosis of:
◦ Meningitis
◦ Meningoencephalitis
◦ Subarachnoid hemorrhage
◦ Malignancy – diagnosis and treatment
◦ Pseudotumor Cerebri
◦ Other neurologic syndromes
To drain C S F & reduce intracranial space
To instill medications
4. Increased intracranial pressure
◦ Head CT before study if focal neurologic findings
present to rule out impending cerebral mass
herniation
• If platelet count is less than 40,000 and
Prothrombin time is less than 50% of control
5. Hydrocephalus- Enlarged ventricle size & in
suspected normal pressure Hydrocephalus
Coma- If C T is negative and I C P increased
Meningitis- Exclude mass lesion & confirm
diagnosis
6. Needle is inserted into subarachnoid space
through intervertebral space
7. Spinal cord ends at L1-L2, so sites for puncture are
located at L3-L4 or L4-L5
Restrain patient in lateral decubitus position
◦ Maximally flex spine without compromising
airway
◦ Keep alignment of feet, knees and hips
◦ Position head to left if right handed or vice versa
8. •Anesthetic such as:
Topical- Zylocaine cream or
Lidocaine 1% with 25 gauge needle
and syringe
•Povidone-iodine solution & sponge
•Drapes, gauze, and bandages
•Manometer, stopcock, tubing and
specimen bottles
•Sterile CSF tray
with
•Spinal needle
9. Obtain a written consent for the procedure
Explain the procedure to the patient
Determine whether patient have any doubts
or misconceptions
Reassure the patient
Instruct patient to void after procedure
10. •Position the patient at one
side of edge of bed
•Place a small pillow under
patient’s head & another
between the legs
•Assist the patient to maintain
position
•Encourage patient to relax & to
breath normally
11. •The physician cleanses the site
with antiseptic solution and drapes
the site
•Local anesthetic is injected to
numb the site and a spinal needle
is inserted to subarachnoid space
with stylet with bevel up to keep
12. A specimen of C S F is collected usually in
three test tubes
Needle is withdrawn & a small dressing is
applied at puncture site
Sent specimen to lab
immediately
13. Instruct patient to lie on prone for 2 to 3
hours
Monitor patient for any complications
Encourage increased fluid intake
14. Headache
Back pain [Occasionally with short-lived ]
◦ Disc herniation if needle advanced too far
Bleeding or fluid leak around spinal cord
Infection, pain, hematoma
Subarachnoid epidermal cyst
Ocular muscle palsy (1%)
Nerve Trauma
Brainstem herniation
15. Throbbing bifrontal & occipital headache
Dull and deep in character
Severe on sitting or standing
IT CAN BE AVOIDED BY:
Using small gauge needle
Keep patient prone after procedure for 2 hours,
then side-lying for 2-3 hours, then supine or
prone for 6 or more hours
17. Clear and colourless
Secreted by choroid plexus
Exists in subarachnoid space
It is about 150-200ml acts as shock absorber
transports nutrients
18. 1. If C S F is blood tinged 3 samples has to be
collected
2. Uniformly stained SA H
3. CSF clears in 3rd bottle-Traumatic trap
1 2 3
1 2 3
19. Usually obtained for cell count, culture,
glucose and protein testing
R B C and Differential W B C
Bacteriological –Gram stain and culture
Biochemical-Protein[0.15-0.45g/l]
- glucose [0.45-0.70g/l]
20. SAH : Spectrophotometry
Malignant Tumor: Cytology
Tuberculosis: Polymerase chain reaction,
Jensen Culture
Non-bacterial Infection: Virology, fungal &
parasitic studies
Demyelinating Disease: Oligoclonal bands
Neurosyphilis: V D R L test
Cryptococcus: culture, antigen detection
H I V : culture, antigen detection & antiviral
antibodies
