Cerebrospinal Fluid Analysis Practice Flashcards

A set of 100 vocabulary flashcards covering cerebrospinal fluid analysis, including anatomy, collection, physical examination, and clinical interpretations.

Meninges

The protective coverings of the brain and spinal cord consisting of three layers: dura mater, arachnoid mater, and pia mater.

Dura mater

The outermost layer of the brain's meninges.

Arachnoid mater

The middle layer of the meninges surrounding the brain.

Pia mater

The innermost layer of the meninges adhering to the surface of the brain.

Subarachnoid space

The space between the pia mater and the arachnoid mater where cerebrospinal fluid (CSF) is found.

Cerebrospinal Fluid (CSF) volume

The total volume in the subarachnoid space, normally ranging from $80-150\,ml$.

CSF Composition

A clear liquid containing glucose, proteins, and ions.

Mechanical protection (CSF)

A function where the fluid floats the brain and softens impacts with the bony walls.

Chemical protection (CSF)

A function providing optimal ionic concentrations for action potentials.

Circulation function (CSF)

The transport of nutrients and waste products to and from the bloodstream.

Origin of CSF

Produced from arterial blood by the choroid plexuses.

Choroid plexuses

Tufts of capillaries with thin fenestrated endothelial cells that produce cerebrospinal fluid.

Modified ependymal cells

Cells with microvilli that cover the capillaries of the choroid plexus.

Fenestrated endothelial cells

The type of capillary cells found within the choroid plexus.

CSF Reabsorption Site

Reabsorbed through the arachnoid villi.

Arachnoid villi

Grapelike clusters of the arachnoid layer involved in fluid reabsorption.

CSF Reabsorption rate

Approximately $20\,ml/hour$, which is equal to the production rate.

Hydrocephalus

A condition involving increased pressure due to the blockage of CSF drainage.

Causes of Hydrocephalus

Include tumor, inflammation, developmental malformation, meningitis, hemorrhage, or injury.

Hydrocephalus treatment

A neurosurgeon implants a drain shunting the CSF to the veins of the neck or the abdomen.

Specimen Collection method

Collected by aseptic lumbar puncture.

Lumbar puncture location

Usually performed in the third or fourth lumbar interspace.

Specimen Collection anesthesia

Local anesthesia is applied for the procedure.

Initial or Opening Pressure

The first pressure reading taken with a manometer attached to a spinal needle.

Manometer

An instrument used to measure the pressure of the cerebrospinal fluid during a tap.

Normal recumbent pressure

Ranges from $50$ to $180\,mm\,Hg$.

Closing pressure

Pressure taken after the collection of the sample, which should be $10$ to $30\,mm$ less than the opening pressure.

Tube #1

The first sequentially labeled tube used for chemistry testing.

Tube #2

The second sequentially labeled tube used for microbiology testing.

Tube #3

The third sequentially labeled tube used for hematology testing.

Normal CSF Appearance

Clear and colorless.

Normal CSF Viscosity

Similar to that of water.

Pleocytosis

An increased number of cells in the cerebrospinal fluid.

Cloudy CSF WBC threshold

Associated with white blood cells (WBCs) $<5\,cells/\mu L$ in some contexts or general cell increase.

Cloudy CSF causes

Presence of white blood cells ($WBCs$), red blood cells ($RBCs$), microorganisms, or increased protein.

Xanthochromia

An abnormal color of the cerebrospinal fluid.

Visible Blood differentiation

The process of distinguishing between a traumatic puncture and subarachnoid or intracerebral bleeding.

Traumatic tap blood distribution

Greatest amount of blood in tube 1, with the least in tube 3.

Hemorrhage blood distribution

A consistent amount of blood across all three collection tubes.

Traumatic tap supernatant

Colorless after centrifugation.

Hemorrhage supernatant

Xanthochromic after centrifugation.

Hemorrhage microscopic findings

Presence of macrophages with phagocytosed red blood cells ($RBCs$).

Normal cell count range

$0$ to $5\,white\,blood\,cells\,per\,microliter\,(WBCs/\mu L)$, typically lymphocytes and monocytes.

Normal RBC presence

Red blood cells ($RBCs$) are not normally present in CSF.

Lysis prevention

Cell counts are performed immediately, or lysing is slowed by storage at $4\,^{\circ}C$.

Hemacytometer

Tool used for microscopic exam on undiluted specimens counting all nine squares on both sides.

Neutrophils in Bacterial Meningitis

Can make up to $90\%$ of the white blood cells.

Early viral, fungal, or TB infections

Conditions where neutrophils may initially be seen in the CSF.

Lymphocytes in Meningitis

Increased in viral, TB, fungal, or syphilitic meningitis, especially in later stages.

Plasma cells in CSF

Antibody-producing cells that are abnormal; seen in multiple sclerosis and chronic inflammatory conditions.

Monocytes in CSF

May be increased in mixed cell patterns such as fungal meningitis or rupture of a cerebral abscess.

Eosinophils in CSF

Levels of $10\%$ or greater are associated with parasitic, fungal, or allergic reactions.

Other cells in CSF

Ependymal, choroid plexus, or malignant cells, often appearing in clumps.

Bacterial Meningitis appearance

Cloudy or turbid.

Viral Meningitis appearance

Clear.

TB Meningitis appearance

Fibrin web.

Fungal Meningitis appearance

Clear or cloudy.

Normal Protein range ($mg/dL$)

Approximately $15$ to $45\,mg/dL$.

Normal Protein range ($g/L$)

$0.15$ to $0.45\,g/L$.

High protein populations

Infants and older adults normally have higher CSF protein levels.

Increased CSF protein causes

Blood contamination, change in blood-brain barrier, decreased reabsorption, or increased CNS synthesis.

Increased synthesis in CNS

A cause of increased protein specifically related to the central nervous system.

Associated conditions for increased protein

Bacterial/viral meningitis, cerebral infarction, hemorrhage, multiple sclerosis, trauma, or flow obstruction.

Decreased protein meaning

The body is rapidly producing spinal fluid or there is a loss of fluid.

CSF/Serum Albumin Index

Used to assess the permeability of the blood-brain barrier.

Normal Albumin Index value

Less than $9$.

Minimal barrier impairment (Albumin Index)

A value between $9$ and $14$.

Moderate to severe barrier impairment (Albumin Index)

A value between $15$ and $100$.

Complete breakdown of barrier (Albumin Index)

A value exceeding $100$.

CSF Glucose Value

Reflects plasma values from $30$ to $90\,minutes$ before collection.

Decreased glucose

Associated with many conditions, specifically meningitis.

Lactate in CSF

Increased in conditions impairing blood supply or oxygen transport to the CNS.

Viral meningitis lactate

Typically remains normal compared to other meningitis types.

Myelin basic protein (MBP)

Seen in multiple sclerosis and other demyelinating diseases.

Gram stain

Microbiological exam used to detect bacteria and fungi.

India ink

Specific microbiological test used for Cryptococcus neoformans.

Acid-fast stain

Specific microbiological test used for tuberculosis (TB) meningitis.

Wright stain

Microbiological stain used for identifying the ameba Naegleria fowleri.

CSF Culture

Used to detect the specific bacterial cause of an infection.

Bacterial Meningitis WBC count

Includes $>1000\,cells/\mu L$ and is predominantly neutrophils.

Viral Meningitis WBC count

Typically $10-500\,cells/\mu L$ and is predominantly lymphocytes.

TB Meningitis WBC count

Typically $100-500\,cells/\mu L$ and is predominantly lymphocytes.

Fungal Meningitis WBC count

Typically $0-500\,cells/\mu L$ and is predominantly lymphocytes.

Bacterial Meningitis Protein level

Significantly increased, often $>1\,g/L$.

Normal CSF:serum glucose ratio

Greater than $60\%$.

Low CSF:serum glucose ratio

Less than $40\%$, seen in bacterial, TB, and fungal meningitis.

Opening pressure in Bacterial Meningitis

Characteristically increased.

Normal Opening pressure ($cmH_2O$)

$10-20\,cmH_2O$.

Acute bacterial meningitis Glucose

Decreased (D) value.

Acute bacterial meningitis Protein

Elevated, specified as $>100\,mg/dL$.

Acute bacterial meningitis WBC count range

$100 - 100,000\,WBCs/\mu L$.

PMN

Polymorphonuclear leukocyte; the major cell type in acute bacterial meningitis.

Cerebral hemorrhage WBC/RBC

Contains $>500,000\,RBCs/\mu L$.

Guillain-Barr syndrome cell type

Predominantly Lymphocytes (L).

Guillain-Barr syndrome glucose

Remains normal (N).

Guillain-Barr syndrome protein

Elevated, specified as $>100\,mg/dL$.

Multiple sclerosis WBC count

Typically $0 - 50\,WBCs/\mu L$.

Spinal cord tumor cell type

Predominantly Lymphocytes (L).

Viral infections WBC count range

$100 - 2,000\,WBCs/\mu L$, predominantly lymphocytes.

Fibrin web appearance

A physical indicator associated with TB meningitis.