CEREBROSPINAL FLUID

Prepared by:Shaimaa sayed , Salma Yahya , Ghada Farah

CONTENTS …Introduction Physical propertiesFunctions Formation Circulation CSF analysis Hydrocephalus

CSF

CSF IS… Clear colorless and transparent fluid.

Circulates through cavity of the :- -brain -subarachnoid space -central canal of spinal cord

Part of extracellular fluid (ECF)

CSF IS… Covered by : -

1. Pia meter (Inner membrane)2. Arachnoid meter (center membrane) 3. Dura meter (Outer membrane)

THE MEMBRANS !!

CSF IS …

Rate of formation :-

About 0.3 ml/minAnd Normally 500ml of CSF is formed

everyday and equal amount is absorbed .

LOCATION OF CSF..Two lateral ventricles Third ventricleFourth ventricleSpinal cord central canal Subarachnoid space Continuous with extracellular fluid of brain parenchyma.

PHYSICAL PROPERTIES ….1-Total volumes

Adults :140 – 170 mlChildren : 10 – 60 ml

PHYSICAL PROPERTIES …2-Spacific gravity : 1.005

3- ph : 7.28 - 7.32

4- appearance : clear

5-composition

PHYSICAL PROPERTIES…For appearance : -

- clear & colorless is Normal - bright red indicate presence of blood

- turbid indicate presence of white cells

FUNCTIONS OF CSF ..Protects & lubricates the brain Provides nutrients ,remove wasteModulates pressure changes serves as a chemical buffer to

maintain constant ionic environment

Serves as a transport medium for nutrients and metabolites ,endocrine substansis and even neurotransmitters

FORMATION OF CSF .. The CSF is formed mainly in the

brain ventricles, and that the majority of the remaining CSF is probably produced by the ependymal surface of ventricles.

It is generally accepted that CSF flows unidirectional from the brain ventricles to the subarachnoid space with the exchange of various substances between the CSF and interstitial compartments.

FORMATION OF CSF ..Choroid plexuses are the main

site of CSF production.Then.. The passage of the plasma

ultra filtrate through the endothelium , facilitated by hydrostatic pressure.

Then.. Passes into the ventricles An active metabolic process

which transforms the ultra filtrate into secretion CSF.

CSF CIRCULATION ..

CSF CIRCULATION .. The amount of CSF formation in the day equal

to the amount of absorption.

Vf = Va

CSF CIRCULATION ..

CSF ANALYSIS

WHY?CSF analysis can accurately

distinguish between a wide range of CNS diseases.

Conditions found by CSF analysis can be placed into four main categories:

1- infectious diseases. 2- hemorrhaging. 3- immune response disorders. 4- tumors.

CSF analysis may be ordered when a patient has one or more of the following symptoms :

severe, unremitting headache stiff neck light sensitivity dizziness speaking difficulties trouble walking or poor coordination fatigue, lethargy, muscle weakness

How to colect the sample to make analysis ??It’s easy by Lumber Puncture

LUMBER PUNCTURE A lumbar puncture (or LP, and colloquially known as a spinal tap) is a diagnostic  procedure that is performed in order to collect a sample of cerebrospinal fluid (CSF) for biochemical , microbiological, and cytological analysis .

APPEARANCE OF CSFIn normal cases, CSF is clear and

colorless.In cases of malady, the

appearance change according to the case.

We will discuss some of these in the following:

1- Xanthochromic : (Bright red or yellow)This indicates the presence of

blood.The appearance of fresh blood in

all tubes supports the diagnosis of a subarachnoid hemorrhage.

2- Turbid :This indicates the presence of

white cells and is suggestive of a CNS infection.

CELL COUNTS1- Increased Neutrophils in CSFThis indicates a bacterial meningitis, cerebral abscess.

2- Increased Lymphocytes in CSF:

This indicates a viral meningitis, tuberculosis, syphilis, fungal and parasitic infections.

Degenerative diseases of the CNS, such as multiple sclerosis, will also generate elevated lymphocyte counts.

CSF DISORDERS1- CSF Glucose: CSF glucose is derived from blood

glucose hence, ideally CSF glucose level should be compared with fasting plasma glucose level for adequate clinical interpretatio

Decrease duo to hypoglycemia , tuberculosis.

Increase duo to high blood sugar.

2- CSF Pressure:Increase duo to increases intra

cranial pressureDecrease due to shock ,fainting or

diabetic coma.

3- CSF Protein :Increase duo to blood in

CSF ,tumor.Decrease duo to rapid CSF

production.

Hydrocephalus(water on brain)

HYDROCEPHALUS The term hydrocephalus is derived

from the Greek words "hydro" meaning water and "cephalus" meaning head.

It is an abnormal collection of cerebrospinal fluid (CSF) resulting in abnormal widening of spaces in the brain.

Causes of “Hydrocephalus” may be: -Excessive production -Decreased absorbtion -Obstruction

TYPES OF HYDROCEPHALUSCommunicating and Non-communicating

Acute and chronic Congenital and acquired

(A)1- Non-communicating (obstructive): CSF circulation is blocked at or proximal to

fourth ventricular outlet foramina.(enlargement of ventricles proximal to the block)

2- Communicating (non-obstructive): due to excessive formation of CSF or lack of

absorption the obstruction of CSF flow is in the

subarachnoid space from prior bleeding or meningitis.

This causes thickening of the arachnoid leading to blockage of the return-flow channels.

(B) 1- Acute : hydrocephalus caused by tumor Develops within days or few weeks Manifests with rapid progression of

symptoms Requires early attention and treatment . 2- Chronic : Over months (or even years) Subtle signs of memory impairment,

walking difficulty, urinary incontinence. Chronic hydrocephalus can present acutely

because of changes in the pathophysiology of the CSF absorption or flow.

(C) 1- Congenital : Present at birth or few weeks/months

after birth.

2- AcquiredInfection (post-meningitis)Post – hemorrhagic (SAH,IVH)Tumors

TreatmentDiversion of CSF: 1- Ventriculoperitoneal shunt 2- Lumboperitoneal shunt