Neurology CSF

How is cerebral spinal fluid formed?

formed by the active secretion of choroid plexus epithelial cells

How is the volume and pressure of cerebral spinal fluid maintained?

cerebral spinal fluid is absorbed by arachnoid villi to maintain a constant volume and pressure

Two functions of cerebral spinal fluid

1.) acts as a shock absorber to protect the brain and spinal cord from trauma

2.) transports nutrients, hormones, and metabolites to the central nervous system

Why do we evaluate cerebral spinal fluid?

changes in cerebral spinal fluid may reflect pathologic changes in the brain or spinal cord

Three things changes in cerebral spinal fluid depend on

1.) type of injury/lesion

2.) location of lesion

3.) stage of lesion

Pleocytosis

increased number of cells in the cerebral spinal fluid

What two diseases cause nuetrophilic pleocytosis?

bacterial meningitis and eastern equine viral encephalitis

What disease causes minimal changes in cerebral spinal fluid?

hydrocephalus

Lesions in what locations will cause abnormal cerebral spinal fluid?

meningeal and paraventricular

Lesions in what locations will cause normal cerebral spinal fluid?

deep parenchymal lesions like some tumors

Will acute or chronic lesions cause abrnomal cerebral spinal fluid?

acute lesions

examples of acute lesions

bacterial meningitis

examples of chronic lesions

atrophy

Four indications for cerebral spinal fluid analysis

1.) abnormal neurologic examination

2.) neck or limb pain

3.) fever of undetermined pain

4.) diagnosis of infectious disease

Three contradictions for cerebral spinal fluid analysis

1.) rabies suspect

2.) anesthesia risk

3.) post trauma or intracranial pressure

How is cerebral spinal fluid collected?

by using sterile technique and a spinal needle with a stylet

Why is it important for cerebral spinal fluid collection to be sterile?

cerebral spinal fluid is extremely susceptible to bacterial infection

After collection, cerebral spinal fluid is placed in a ________ tube

lavender top

Why is cerebral spinal fluid placed in a lavender top tube?

cerebral spinal fluid itself doesn't clot, but the blood that can be collected in trace amounts will

After being collected, how is cerebral spinal fluid stored?

stored at 4 degrees celsius for ups to 24 hours

How soon must cerebral spinal fluid be processed after collection (if not going to be refridgerated)?

30 minutes

Why must cerebral spinal fluid be processed so soon?

cells will begin to deteriorate because of the low protein concentration in cerebral spinal fluid

Normal cerebral spinal fluid is ________ and __________

colorless; clear

How will cerebral spinal fluid appear with blood contamination/acute hemorrhaging?

bright red

How will cerebral spinal fluid appear with prior hemorrhaging?

dull red, brown, or yellow (xanthochromia)

What is cerebral spinal fluid measured in?

mg/dL

Most of the cerebral spinal fluid protein is...

albumin from plasma

What is the most common abnormality in cerebral spinal fluid?

increased protein concentration

Albuminocytologic dissociation

an increase in cerebral spinal fluid protein but normal cell count

What cells are counted during cerebral spinal fluid analysis?

red blood cells and white blood cells (counted manually)

Mild pleocytosis indicates...

viral infections, trauma, and vascular disease

Severe pleocytois indicates...

bacterial infection

Is it normal to see red blood cells in cerebral spinal fluid?

no; usually means there was a traumatic tap or from hemorrhage

What white blood cells are commonly seen in cerebral spinal fluid?

mononuclear cells and lymphocytes (80-90% of cells), neutrophils (10%)