Meninges/Ventricles/CSF

Question 0

Supratentorial lesion

Answer 0

Common in adult; impedes the flow of the Great Cerebral Vein of Galen

-Decreased venous outflow from brain

Question 1

Major area where CSF is returned to the systemic circulation

Answer 1

Superior Sagittal Sinus

-Also a location where infxn can spread to the CNS from the bone, scalp nose

Question 2

Contents of subarachnoid space

Answer 2

1. Trabeculae
2. CSF
3. Blood vessels

Question 3

Cisterna magna

Answer 3

“Cerebromedullary cistern”

Spans over the space of the cerebellum and the medulla

Question 4

Pontine cistern

Answer 4

Lies over the pons

Question 5

Interpeduncular cistern

Answer 5

Lies over the interpeduncular fossa; holds the Circle of Willis

Question 6

Lumbar Cistern

Answer 6

extends from L1/L2 to S2; location where spinal taps and intrathecal injections are performed

Question 7

Virchow-Robin spaces

Answer 7

Vessels that pass into the brain carrying a sleeve of pia and subarachnoid space

-In older individuals w/ decreased brain volume, CSF can collect here and appear as bright spots on an MRI

Question 8

CSF Circulation

Answer 8

1. CSF passes thru the interventricular foramen of Monro located in the septum pellucidum (divides the anterior horns) to the 3rd ventricle
2. Passes thru the aqueduct of Sylvius to the 4th ventricle
3. Enters the subarachnoid space via the lateral foramina of Luschka and the medial foramen of Magendie
4. Circulates around the brain andd thru the cetnral canal of the spinal cord

Question 9

Cerebral Perfusions Pressure Equation

Answer 9

CPP= MAP-ICP

Question 10

Uncal herniation

Answer 10

Protrusion of the uncus of the temporal lobe through the tentorial notch

Causes:

1. Decreased consciousness
2. Pupil dilation on side of herniation
   
   • compression of parasympathetic fibers on III

Question 11

Tonsillar Herniation

Answer 11

Protrusion of the tonsil of the cerebella thru the foramen magnum; life-threatening

• Compresses the medulla where respiratory and CV centers are located
• Pt. shows decreasing level of consciousness and abnormal breathing

Question 12

Berry aneurysm

Answer 12

Occurs in the anterior part of the circle of Willis

• Sudden, sever headache, stiff neck, altered consciousness

Question 13

Nuchal rigidity

Answer 13

Resistance to neck flexion; seen in a # of conditions

Question 14

Fracture to base of the skull

Answer 14

Can have leakage of CSF from nose, bleeding from ears

-Increased risk of meningeal bleeding and infxn

Question 15

mild TBI

Answer 15

Concussion

Damages the white matter of the prefrontal cortex

*Risk factor for developing Alzheimer’s disease/ALS if repeated

Question 16

Non-communicating hydrocephalus

Answer 16

Blockage of the flow of fluid from one of the ventricles

• common in the cerebral duct; also in infants w/ mothers w/ mumps/rubella
• If possible, a shunt should be run to drain the fluid

Question 17

Communicating hydrocephalus

Answer 17

Caused by increased production/reduced absorption of CSF

• Can occur w/o increase in ICP in geriatric population
• Possible life-threatening sequelae of meningitis

Question 18

Bacterial meningitis

Answer 18

inflammation of the meninges/space b/w the meninges

• high fever, irritability, lethargy, photophobia, nuchal rigidity, severe headache
• Can lead to permanent hearing loss, intellectual disability, or limb amputation

Question 19

Encephalitis

Answer 19

inflammation of the brain

-usually viral

Question 20

Great Cerebral Vein of Galen

Answer 20

Collects venous blood from the internal cerebral veins

-Supratentorial lesions impede venous flow thru this vein

=>compression hemorrhage

Question 21

Chronic Traumatic Encephalopathy

Answer 21

Repeated head trauma

=>memory loss, paranoia, depression