csf investigation

CSF INVESTIGATIO

NBY

DR DEEPTI PATILDEPT. OF DRAVYAGUNA

04/07/2023 CSF INVESTIGATION 2

INTRODUCTION

• Cerebrospinal fluid (CSF) analysis is a set of

laboratory tests that examine a sample of the

fluid surrounding the brain and spinal cord.

• CSF is an ultra filtrate of plasma.

• It is clear and colorless.


Conti…

• It contains glucose, electrolytes, amino acids,

and other small molecules found in plasma

• CSF protects the central nervous system from

injury,

• Provides nutrients, and removes waste

products by returning them to the blood.


ALTERNATE NAMES

Spinal tap;

Ventricular puncture;

Lumbar puncture;

Cisternal puncture;

Cerebral spinal fluid culture


CONDITIONS TO INVESTIGATE

1. Chronic inflammatory

polyneuropathy

2. Dementia due to

metabolic causes

3. Encephalitis

4. Epilepsy

5. Febrile seizure (children)

6. Generalized tonic-clonic

seizure

7. Hydrocephalus

8. Inhalation anthrax

9. Normal pressure

hydrocephalus (NPH)

10. Pituitary tumor

11. Reye syndrome


NORMAL VALUES

• Gross appearance: Clear and Colorless.

• CSF opening pressure: 50–175 mm H 2 O.

• Specific gravity: 1.006–1.009.

• Glucose: 40–80 mg/dL.

• Total protein: 15–45 mg/dL.


Conti…

• Leukocytes (white blood cells): 0–5/microL

(adults and children); up to 30/microL

(newborns).

• Differential: 60–80% lymphocytes; up to 30%

monocytes and macrophages; other cells 2%

or less. Monocytes and macrophages are

somewhat higher in neonates.


Conti…• Chloride: 110 - 125 mEq/L

• Gram stain: negative.

• Lactate: less than 35 mg/dL.

• Red blood cell count: No red blood cells in CSF

• LD: 1/10 of serum level.


TEST PROCEDURE• The patient lies on his or her side, with knees pulled

up toward the chest, and chin tucked downward.

• After the back is cleaned, the health care provider

will inject a local numbing medicine (anesthetic) into

the lower spine.

• A spinal needle is inserted, usually into the lower

back area. Fourth and fifth lumbar vertebrae (L4-L5).


Conti…• Once the needle is properly positioned, CSF

pressure is measured and a sample is

collected.

• The needle is removed, the area is cleaned,

and a bandage is placed over the needle site.

The person is often asked to lie down for a

short time after the test.


POST OPERATIVE CARE

• Site of the puncture is covered with a sterile bandage.

• The patient should remain lying down for four to six hours after the lumbar puncture.


Conti…

• Vital signs should be monitored every 15

minutes for four hours, then every 30 minutes

for another four hours.

• The puncture site should be observed for signs

of weeping or swelling for 24 hours.

• The neurological status of the patient should be

evaluated


RISK• Bleeding into the spinal canal

• Discomfort during the test

• Headache after the test occurs in 10–30% of adult

patients and in up to 40% of children

• Hypersensitivity (allergic) reaction to the anesthetic

• Infection introduced by the needle going through the

skin


PURPOSE

• To measure pressures within the cerebrospinal

fluid and

• To collect a sample of the fluid for further testing.

• CSF analysis is used to diagnose certain neurologic

disorders, particularly infections (such as

meningitis) and brain or spinal cord damage


CONSIDERATIONS

This test is dangerous for people with:

• A tumor in the back of the brain that is

pressing down on the brain stem

• Blood clotting problems

• Thrombocytopenia


ABNORMAL CSF COLOUR

• Cloudy CSF:- Infection or a build up of white blood

cells or protein.

• Bloody or red CSF:- Bleeding or spinal cord

obstruction.

• Brown, Orange, or Yellow:- sign of increased CSF

protein or previous bleeding (more than 3 days ago).


CSF PRESSURE

• Increased CSF pressure:- Increased intracranial

pressure (pressure within the skull).

• Decreased CSF pressure:- spinal cord tumor,

shock, fainting, or diabetic coma.


PROTEINS

• Increased CSF protein:- Blood in the CSF,

diabetes, polyneuritis, tumor, injury, or any

inflammatory or infectious condition.

• Decreased protein is a sign of rapid CSF

production.


CSF Gamma Globulin

• Increased CSF gamma globulin levels may be

due to diseases such as

Multiple sclerosis

Neurosyphilis, or

Guillain-barre syndrome


CSF Glucose

• Increased CSF glucose:- Sign of high blood

sugar.

• Decreased CSF glucose:- Hypoglycemia (low

blood sugar), bacterial or fungal infection (such

as meningitis), tuberculosis, or certain other

types of meningitis.


White Blood Cells

• Increased white blood cells in CSF:-

Sign of meningitis, acute infection,

beginning of a chronic illness, tumor, abscess,

stroke, or demyelinating disease (such as

multiple sclerosis).


RED BLOOD CELLS

• Red blood cells in the CSF sample may be a

sign of bleeding into the spinal fluid

• Traumatic lumbar puncture.


LACTATE DEHYDROGENASE

• This enzyme is elevated in bacterial and

fungal meningitis, malignancy, and

subarachnoid hemorrhage.


GRAM STAIN

• The Gram stain is performed on a sediment of

the CSF

• Positive in at least 60 percent of cases of

bacterial meningitis.

• Culture is performed for both aerobic and

anaerobic bacteria.


Average and Range of Cerebrospinal Fluid Protein

ConditionAverage: mg per dL (g per L)

Range: mg per dL (g per L)

Bacterial meningitis 418 (4.18) 21 to 2220 (0.21 to 22.2)

Brain tumor 115 (1.15) 15 to 1920 (0.15 to 19.2)

Brain abscess 69 (0.69) 16 to 288 (0.16 to 2.88)Aseptic meningitis 77 (0.77) 11 to 400 (0.11 to 4.0)Multiple sclerosis 43 (0.43) 13 to 133 (0.13 to 1.33)Cerebral hemorrhage 270 (2.7) 19 to 2110 (0.19 to 21.1)

Epilepsy 31 (0.31) 7 to 200 (0.07 to 2.0)Acute alcoholism 32 (0.32) 13 to 88 (0.13 to 0.88)Neurosyphilis 68 (0.68) 15 to 4200 (0.15 to 42.0)


Typical Cerebrospinal Fluid Findings in Various Types of Meningitis

Test Bacterial Viral FungalTubercul

arOpening pressure

Elevated Usually normal Variable Variable

White blood cell count

≥1,000 per mm3 <100 per mm3 Variable Variable

Cell differential Predominance of PMNs*

Predominance of lymphocytes†

Predominance of lymphocytes

Predominance of lymphocytes

Protein Mild to marked elevation

Normal to elevated

Elevated Elevated

CSF-to-serum glucose ratio

Normal to marked

decrease

Usually normal Low Low


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csf investigation

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