CEREBROSPINAL FLUID.PPT

7/27/2019 CEREBROSPINAL FLUID.PPT

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Cerebrospinal Fluid (CSF)

LocationVentricular system

Subarachnoid space (including cysternal system)

Function Protect the CNS from mechanical insult (as a cushion)

Maintain the equilibrium of neuronal and glial

Remove the waste products of neuronal metabolism

Determine pulmonary ventilation andCBF according to its acidity



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CSF

Aim of its examination

Diagnostic

Treatment evaluation or follow up

Prognostic

Formation

Rate – 0.35 mL/minute ~ 500 mL/day

Formed by :Choroid plexuses at :

Floor of each lateral ventricles (largest and

most important)

Roofs of the third and fourth ventricles (smaller)Capillary beds that supply the pia and

arachnoid (smaller)

Ependyma and adjacent glial elements (smaller)



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CSF

Formation (ctnd)

A complex process : Active transport (expenditure of energy)

Passive diffusion

Active transport

Cuboid epithelial cells (in choroid pelxus) secrete Na ion

Positive potential attracts negative ion especially Cl

Many of ionic solutes increase osmotic pressure

Water and other solutes follow in

maintaining osmotic equilibrium

Passive diffusion

Continual diffusion occurs at :

Ependyma and vascular beds



CSF

DynamicTotal volume of CSF : 75 – 100 mL

( 15-40 mL at ventricular system)

Rate of production 0.35 mL/min ~ 500 mL/day

Daily turn over 4-5 times

CirculationLateral ventricles Monro foramenThird ventricle

Sylvii aqueductFourth ventricle

Luschka and Magendie foramina

Subarachnoid space (cysternal system)superior and lateral convexity of brain hemispheres

Arachnoid villi

venous sinuses

(venous blood flow)



CSF

AbsorptionMainly at Arachnoid villi (Arachnoid granulation or

Pacchionian bodies)

Others (smaller) : veins and capillary of piamatter

Unidirectional (valve)

Mechanism - Depends on :

Hydrostatic pressure (high to low)

Colloid osmotic pressure (low to high)

Active transport by cells formingthe walls of the arachnoid villi



CSF

Composition

Water

Small amount of protein

Gases in solution (O2 and CO2)Na+, K+, Ca2+, Mg2+, Cl-, Glucose

A few white cell

Organic constituents



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CSF

Normal values

Color Clear, colorlessPressure 70-200 mmH2O

Cell 0-5/mm3 (lymphocyte or mononuclear cell)

Glucose 45-80 mg%

Protein 5-15 mg% (ventricles)

10-25 mg% (cysternal)15-45 mg% (lumbar)

-globulin 5-22 % total protein

Osmolaritas 295 mOsmol/L

pH 7.31

Natrium 142-150 mEq/LKalium 2.2-3.3 mEq/L

Chloride 120-130 mEq/L

Magnesium 2.7 mEq/L

CO2 25



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CSF

Color

Clear, colorlessChange in color : Cell > 200 / mm3 (RBC > 1000 red color)

Traumatic puncture : 3-tubes test

More pale

clear

blood

xantho-

chrom

bloodUnchange



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CSF

Pressure

Depends on :Rate of formation and absorption

Flow disturbance

Measurement :

Manometer while Lumbar or Cysternal puncture

Position :

Lateral decubitus : Normal pressure 70-200 mmH2O

Sitting : 280 mmH2O

Normally slight increase in case of

Coughing or straining

Change in heart beat and respiratory cycle

Pressure on abdomen



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CSFPressure

Change in flow disturbance

Queckenstedt Test – press on jugular veins result in

normally increase CSF pressure and return to normal limit in10 “

CSF obstruction nothing or slightly increase CSF pressure

Cell : Leucocytes or PMN means pathologic I.e infection of

bacterial, fungal, viral, chemical agents, tumor

Protein : higher than normal limit means pathologic condition

Glucose : two third of blood glucose; below 40 mg% abnormal (i.e in pyogenic infection,

tuberculous/fungal meningitis)

Electrolytes : low chloride concentration meningitis (but

not specific)



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CSF

Osmolality : similar to blood plasma

Acidity (pH) : Lower than blood

pCO2 : Higher than blood

In subacute or chronic metabolic acidosis :

CSF acidity relatively un-changed



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CSF

Disorders of CSF

Flow disurbance Accompany other diseases

Flow disturbance

Obstruction occurs in CSF flow in ventricular system or subarachnoid space

Result in Hydrocephalus

Non-communicating :Common in children

Caused by aqueduct stenosis, over-growth of foramina

Luschka and Magendie



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CSF

Disorders of CSF

Communicating hydrocephalus

Common in adultFree communicating between ventricles and subarachnoid space

Obstruction at subarachnoid space

Caused by inflammation, subarachnoid bleeding, tumor growth



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CSF|LP

LUMBAL PUNCTURE

Indication :Measure CSF pressureObtain sample for cell count, chemical work-up,

bacteriology

Intrathecal treatment/procedure :spinal anesthesia,antitumors, antibiotics

Diagnostic procedure : pneumoencephalography,myelography, scintigraphic cysternography



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CSF|LP

Indications:

•Suspect meningitis

•Suspect encephalitis•Diagnose meningeal carcinomatosis

•Diagnose tertiary syphilis

•Diagnose meningeal leukemia

•Staging of lymphomas;•Follow up therapy for meningitis

•Evaluation of dementia

•Evaluation for Guillain-Barre

•Treat pseudotumor cerebri

•Evaluation for multiple sclerosis

•R/O subarachnoid hemorrhage (after neg. head CT)

•Instillation of drugs, anesthetics, or radiographic media

into CNS



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CSF|LP

Technique

Preparation :Take blood sample for glucose 15’ before LP Explain the procedure to patientObtain informed consent

Exclude possibility of increased ICP or CNS mass lesion (eye exam/ head CT).

Position :Lateral decubitus in full flexion posture

At the bed sideSmall cushion on head or knee (if needed)



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CSF|LP

Technique

Site of punctureInter-vertebral space at vertebra L3 – L4Imaginary line connecting iliac crestsOther site (if failed) : L2-L3 or L4-L5

Infant/children at L4-L5

CSF|LP



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CSF|LP

Technique

Sitting position if failed in recumbent (2-3 times)Measure (opening) pressure

Patient preparationAseptic technique :Clean the area using iodine 10%

application in round movestarting from the center

Change glove onceUse sterile covering/towel

CSF|LP



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CSF|LP

Technique

Insertion :All tools available : spinal needle (18,19,20),

manometer, sterile bottles (3)Local anesthetic (lidocaine 1-2%) :

0.1-0.2 mL subcutaneous and0.2-0.5 mL deeperIntroduce spinal needle, with bevel turned up,

into interspace, in a horizontal direction,

with slightly cephalad inclination

("aim for the belly button"). Always have stylish in place when

maneuvering needle in interspace.

CSF|LP



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CSF|LP

•Measure opening pressure (normal is 100-250 mmHg): If

pressure elevated, ask pt to relax and ensure that there isno abdominal compression or breath holding (straining

and abdominal pressure can increase ICP).

•If pressure markedly elevated, remove only 5 cc of spinal

fluid and remove needle immediately.

•Else, collect 15-20 cc in four collection tubes (2 cc per

tube), and remove needle (with styled in place). Can send

extra fluid in tube #3, or in extra red-top (#5).

•Instruct pt to lie flat for approx. 4 hrs to minimize post LP

headache (caused by CSF leakage).

CSF|LP



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CSF|LP

Contraindications:

•Infection at intended site of LP

• Anticoagulation;•Increased intra-cranial pressure

•Severe hemorrhagic diathesis

•CNS mass lesion in posterior fossa

•Suspect venous sinus occlusion

CSF|LP



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CSF|LP

Complication

Headache

BackacheIntracranial subdural hematoma

Infection

CSF leak

Herniation

CEREBROSPINAL FLUID.PPT

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