Chapters 29 30 Tripple

CSF & BBB „ „

Cerebrospinal fluid Blood Brain Barrier

Ventricular System „

Ependymal cells Left & right

„

Third

„

Fourth Contiguous with subarachnoid space

„

… Foramen

… Aqueduct

„

of Monro of Sylvius

Ventricular System

1

Lateral Ventricles Anterior horn Body „ Atrium „ Posterior horn „ Inferior horn „ „

Third Ventricle

Suprapineal recess Optic recess „ Infundibular recess „ „

Aqueduct of Silvius Narrow canal between third and fourth ventricles „ Stenosis (narrowing) or obstruction „

… Accumulation

of CSF in cerebrospinal pressure … Ventricular dilation rostral to the obstruction … Increase

2

Fourth Ventricle „

Connects with Subarachnoid space … Foramen „

… Foramen „

of Magendie

Midline

of Luschka

2 lateral

Ventricle Lining „ „

Ependymal epithelium Choroid plexus … Vascular

pial involding atrium, inferior horn of lateral ventricle … Foramen of Monro … Roof of third ventricle … Posterior part of roof of fourth ventricle … Body,

„

Not present in anterior horn of lateral ventricles … Location

of shunts for draining CSF in hydrocephalus

Subarachnoid Cisterns „

Cisterna magna … Largest „

Between medulla, cerebellum and occipital bone

… Cisternal

„

puncture

Medullary cistern … Vertebral

arteries run through it

3

Subarachnoid Cisterns „

Cisterna pontis … Basis

pontis segment

… Midline „

…2

Determien pontine tumors

laterals „

Tumors in cerebellopontine angle

… Basilar

artery & CNVI (abducens) runs through it

Subarachnoid Cisterns „

Cisterna interpeduncularis … Between

cerebral peduncles … Oculomotor nerve

Subarachnoid Cisterns „

Suprasellar cistern … Pathology

around optic chiasm „

Superior cistern

„

Spinal cistern:

… Vein

of Galen

… Lumbar „

cistern

Spinal tap

4

Choroid Plexus „ „ „

„

Produces CSF Villi extend into CSF Fenestrated capillaries in connective tissue Cuboidal epithelium line villi … Microvilli … Tight „

junctions

Prevent macromolecular substances from entering CSF

CSF Made by choroid plexus & ependymal lining Turns over 4-5 times/day „ Formed by: „ „

… Diffusion „

Water, respiratory gases, chloride, alcohol, and some CNS drugs

… Active „

transport

Sodium, potassium, glucose, amino acids, proteins

CSF: Circulation AG: arachnoid granulations „ SSS: superior sagittal sinus „

5

CSF: Circulation „

Drift

„

Oscillation

… Positive

to negative balance

… To-and-fro

„

movement

Pulstaile movement … Rhythmic

movements synchronous with pulse in 4th ventricle

… Up-and-down

CSF: Resorption „ „ „ „ „ „ „

Arachnoid granulations into superior sagittal sinus Arachnoid membrane Meningeal blood vessels Choroid plexus Ependyma of ventricles Capillary endothelium Cranial/spinal nerve sheaths

CSF: Functions Buoyancy/support „ Cushion/buffer between brain and skull „ Stable chemical environment „

6

CSF: Composition „ „

Water Protein …

„ „

If you find myelin products: multiple sclerosis

Sugar Cells …

WBCs „

Leukocytes

„

Lymphocytes

…

…

…

Increase in bacterial meningitis Increase in viral meningitis

RBCs „

Only in trauma/hemorrhage

„

Electrolytes

„

Peptides

…

Sodium, potassium, chloride, magnesium, and calcium

Barrier System „

Blood-brain barrier … Interface

between capillaries and brain ECM

„

Blood-CSF barrier … Interface

between choroid plexus and CSF

Meningitis „

Bacterial meningitis

„

Viral meningitis

… Cloudy

… Clear

… Increased

… Normal

pressure … Leukocytes … Increased protein … Low glucose

pressure (or slightly increased) cells (lymphocytes) … Normal protein … Normal glucose … Normal

7

Multiple Sclerosis Clear Normal pressure „ Normal or increased cells (lymphocytes) „ Normal or moderately increased protein (myelin basic proteins) „ Normal glucose „ „

Tumors Clear „ Increased pressure „ Normal or increased cells (tumor) „ Increased protein „ Normal glucose „

CSF In Disease

8

Ventriculomegaly „

Overproduction of CSF … Choroid

plexus

tumor

Ventriculomegaly „

Overproduction of CSF … Choroid

plexus

tumor „

Cerebral atrophy … E.g.

Alzheimer’s or infarct

Ventriculomegaly „

Overproduction of CSF … Choroid

plexus

tumor „

Cerebral atrophy … E.g.

Alzheimer’s or infarct

„

Developmental

9

Ventriculomegaly „

Overproduction of CSF

„

Cerebral atrophy

… Choroid

plexus tumor

… E.g.

Alzheimer’s or infarct

„ „

Developmental Obstruction of CSF flow

Hydrocephalus „ „

Increased CSF in ventricles Communicating … Free

communication between ventricles and SAS. … Obstruction in „

„

„

Noncommunicating … Obstruction „ „ „

in

Foramen of monro Aqueduct of sylvius Foramina of Magendie and Luschka

SAS (fibrosis from infection) Arachnoid granulations

Foramen of Monro Obstruction

10

Aqueduct of Sylvius Obstruction

Bobble Head Doll Syndrome Childhood disorder „ Rhythmic nodding of head „

… Not

while lying on back and sleeping

Intermittent obstruction of the foramen of Monro by an intraventricular cyst „ Bobbing head „

… Learned

behavior that relieves obstruction

Bobble Head Doll Syndrome

11