Cranium, ventricles, & meninges Flashcards Preview

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Flashcards in Cranium, ventricles, & meninges Deck (63):
1

The blood-CSF barrier is formed by

Choroid epithelial cells

2

Usual cause of subdural hematoma

Rupture of bridging veins, which are particularly vulnerable to shear injury

3

The middle meningeal artery runs through the

Epidural space

4

The blood-brain barrier is made up of

Capillary endothelial cells

4

Consequences of early hydrocephalus on brain development

Stretch or destroy CC; affects WM tracts, esp. projection fibers near midline; disrupt myelination, resulting in decreased cortical mantel; decreased brain mass, thinning of posterior brain regions; multiple surgeries to correct shunt

5

Radiological appearance of epidural hematoma

Lens-shaped biconvex hematoma, usually does not spread past cranial sutures where dura is attached to the skull

6

Mild central herniation can lead to traction on which cranial nerve?

CN VI, producing lateral rectus palsy

7

Normal intracranial pressure

8

Meninges, from inside to outside

Pia, arachnoid, dura

8

Tentorium cerebelli

Tentlike sheet of dura that covers the upper surface of the cerebellum

9

Cisterns

Widening of subarachnoid space to form large CSF lesions

9

Symptoms of increased CSF

Headache worse lying down, altered mental status (irritability, depressed alertness & attention), nausea/vomitting, papilledema, visual loss, diplopia

10

CSF enters the subarachnoid space via

Lateral foramina of Luschka & midline foramen of Magendie

11

Subarachnoid space

CSF-filled space between the arachnoid & pia; major arteries of the brain travel through this space

12

Falx cerebri

Separates the 2 cerebral hemispheres

14

What is the normal adult volume of CSF?

150cc, 500cc produced per day

16

Choroid plexus

Epithelial tissue in ventricular system that secretes CSF; found in the lateral ventricles & the roof of the 3rd & 4th ventricles

17

The bridging veins run through the

Subdural space

17

What type of herniation can cause infarcts in the ACA territory?

Subfalcine herination

17

Xanthochromia

CSF discoloration due to presence of blood for 1+ day; associated with subarachnoid hemorrhage

18

Most common cause of epidural hematoma

Rupture of the middle meningeal artery due to fracture of the temporal bone by head trauma

19

Arachnoid layer

Adheres to inner surface of dura

20

The cervicomedullary junction occurs at the level of the

Foramen magnum

21

What type of herniation is associated with compression of the medulla

Tonsillar herniation Leads to respiratory arrest, BP instability, death

22

Radiological appearance of subarachnoid hemorrhage

Blood tracks down into sulci following contours of the pia

22

Pia mater

Adheres closely to the surface of the brain & surrounds the initial portion of each blood vessel as it penetrates the brain surface

23

Hydrocephalus can result from

Increased production/decreased absorption of CSF Blockage of one of the normal outflow pathways of the ventricular system

24

Kernohan's phenomenon

As midbrain is pushed to side by uncus in uncal herniation, it is pushed away from the side of the mass. The side opposite the mass then becomes compressed against the tentorial notch, leading to ipsilateral hemiplegia.

25

What is the most common cause of lobar hemorrhage?

Amyloid angiopathy

26

Tentorium cerebelli

Covers the upper surface of the cerebellum

28

Pseudotumor cerebri

Elevated ICP/edema without mass lesion

28

Leptomeninges

Pia & arachnoid

29

Neuropsych effects of hydrocephalus in children

PIQ< language problems with rapid retrieval of info, automaticity, language discourse, cocktail party speech Deficits in both verbal & visual memory, exec deficits

30

Communicating hydrocephalus

Excess CSF due to either bad absorption or over production

30

Colloid cyst

Benign neoplasm composed of epithelial cells surrounded by a capsule & filled with a gelatinous substance; commonly arise from the roof of the 3rd ventricle

31

Ventriculostomy

Establishes free communication between the floor of the 3rd ventricle & the underlying interpeduncular cistern

32

Hypertensive hemorrhages are most common in what areas of the brain?

BG, thalamus, cerebellum, pons

33

Is vasospasm more common in traumatic or nontraumatic subarachnoid hemorrhage?

Nontraumatic

35

Symptoms of chronic subdural hematoma

HA, cognitive impairment, unsteady gait

36

Cerebral aqueduct/Aqueduct of Sylvius

Canal draining CSF from 3rd to the 4th ventricles through the midbrain; common site of obstruction causing childhood hydrocephalus

37

What pattern of IQ performance is typically observed in children with early-onset hydrocephalus?

VIQ>PIQ

38

Calvaria/calvarium

Upper dome-like portion of the skull

40

Risk factors of pseudotumor cerebri

Female, adolescent, obesity, menstrual abnormalities

41

Clinical triad of uncal herniation

Blown pupil (compression of CN III), HP (compression of cerebral peduncles), coma (distortion of midbrain RF)

42

What is the most common cause of nontraumatic subarachnoid hemorrhage?

Rupture of arterial aneurysms (75-80%)

43

The anterior, middle, & posterior fossa contain which brain structures?

Anterior - frontal lobe Middle - temporal lobe Posterior - cerebellum & brainstem

45

Radiological appearance of subdural hematoma

Crescent-shaped

46

Which brain region is most often affected by hydrocephalus?

Posterior regions

47

Obstructive hydrocephalus

Obstruction of CSF drainage from the lateral & 3rd venricles; commonly seen with brainstem tumor or posterior fossa tumor; can result from congenital stenosis of aqueduct of Sylvius

48

What 3 ways is hydrocephalus classified?

Complicated or noncomplicated Communicating or noncommunicating Congential or postnatal

50

Cushing's triad

HTN, bradycardia, irregular respiration

51

Most common cause of perinatal & postnatal hydrocephalus (besides spina bifida)

Intraventricular hemorrhage

53

Vasogenic vs cytotoxic edema

Vasogenic: excessive extracellular fluid Cytotoxic: excessive intracellular fluid within brain cells caused by cellular damage

54

Cocktail party syndrome (CPS)

Communication style characterized by excessive verbiage that lacks clarity, organization, & relevance (often seen in childhood hydrocephalus)

55

In what areas is the blood-brain barrier broken?

Pituitary gland (entry of chemicals that influence hormones), pineal gland (entry of chemicals that affect day-night cycles), area postrema (entry of toxic substances that induce vomiting

56

Two layers of the dura

Periosteal & meningeal

57

Children with prenatal obstructive hydrocephalus are more prone to exhibit difficulties with

Visuospatial & visuomotor abilities

58

How is increased CSF/ICP treated?

Steroids, mannitol, hyperventilation (vasoconstriction), shunt, external ventricular drain

59

Dura mater

Outermost meningeal layer

60

Alterations in the amount of CSF may reflect

Nervous system impairment (bacterial meningitis, myelitis, MS, SAH) or germ cell proteins

61

Symptoms of nontraumatic subarachnoid hemorrhage

Sudden catastrophic HA, meningeal irritation, CN & other focal deficits, impaired consciousness

62

Symptoms of pseudotumor cerebri

Generalized, bilateral headache, bilateral VI palsy, visual deficits due to swelling of optic disk

63

Falx cerebri

Suspended from roof of cranium, separates left & right hemispheres