Dural venous sinuses + fossa + hemorrhages

Question 1

Where are dural venous sinuses?

Answer 1

Between the outer periosteal and the inner meningeal layers of the dura

Question 2

Occipital sinus

Answer 2

In the falx cerebri against the occipital bone; communicates inferiorly with vertebral plexus of veins; drains into confluence

Question 3

Basilar sinus - location, drainage

Answer 3

Location: clivus, just posterior to the sella turcica of the sphenoid

Connects the inferior petrosal sinuses to each other and to the vertebral plexus of veins along the clivus

Question 4

Dural venous sinuses as a conduit for extracranial to intracranial infection

Answer 4

• Emissary veins: pass from outside the cranial cavity to the dural venous sinuses
• Diploic veins from inside the bone
• Cerebralspinal fluid

Valveless

Question 5

Most common dural venosu sinus thrombosis

Answer 5

Superior sagittal sinus –> cerebral edema, raised intracranial pressure, hemorrhage

Question 6

Subdural hematoma formation

Answer 6

A briding vein near the site of entry to the superior sagittal sinus tears

Question 7

Where are the cavernous sinuses?

Answer 7

The paired cavernous sinuses lie against the lateral aspect of the body of the sphenoid bone on either side of the sella turcica

Question 8

The cavernosu sinuses receive blood from

Answer 8

• Cerebral veins
• Ophthalmic veins
• Emissary veins
• Sphenoparietal sinuses

Question 9

The right and left cavernous sinuses are connected by

Answer 9

The intercavernous sinuses anterior and posterior to the pituitary stalk

Question 11

What structures pass through each cavernous sinus? What structures are just withint he wall?

Answer 11

• Inside the cavernous sinus:
  
  • Internal carotid artery
  • CN VI (Abducens)
• In the lateral wall of each cavernous sinus:
  
  • CN 3 (Oculomotor) & 4 (Trochlear)
  • V1 (Ophthalmic) & V2 (Maxillary

Question 12

Middle meningeal artery

Answer 12

• Branch of the maxillary artery that enters the middle cranial fossa through foramen spinosum and provides blood supply to the dura
• Close to the pterion
• Epidural hematoma

Question 13

Maxillary artery anatomy

Answer 13

• Divides into anterior and posterior branches

Question 14

Accessory meningeal artery

Answer 14

• Branch of the maxillary artery that enters the middle cranial fossa via the foramen ovale
• Supplies dural areas medial to the foramen

Question 15

Falx cerebri attachment to anterior cranial fossa

Answer 15

Frontal crest

Question 16

What’s anterior boundary of the middle cranial fossa? What’s the posterior boundary of the middle cranial fossa? What is above the middle cranial fossa?

Answer 16

• Anterior: chiasmatic sulcus
• Posterior: anterior surface of the petrous part of temporal bone
• Above: temporal lobes of brain

Question 18

What foramen are in the middle cranial fossa?

Answer 18

optic canal

superior orbital fissure

foramne rotundum

foramen ovale

Question 19

What is this?

Answer 19

Epidural hemorrhage

• Usually does not cross suture lines because dura is adherent to skull firmly at the suture lines
• Lentiform in shape
• Usually from fracture and laceration of middle meningeal artery

Question 20

What type of hemorrahge is crescent-shaped, crosses suture lines, and does not cross the falx?

Answer 20

Subdural hemorrhage

• Acute is hyperdense
• Subacute is isodense
• Chronic is hypodense

Question 21

What is this?

Answer 21

• Subarachnoid hemorrhage: hemorrhage in subarachnoid space due to trauma or rupture of an intracranial aneurysm or other vascular abnormality (such as arteriovenous malformation)
  
  • Areas that were occupied by CSF are now occupied by blood
  • Symptom: worst headache of life
• Most common aneurysm: anterior communicating artery

Question 22

Which is INcorrect?

• Hemorrhage is often associated with a skull fracture
• The clinical presentaiton may involve a lucid interval followed by deterioration after a head trauma
• The hemorrhage results from venous injury most commonly
• The hemorrhage does not usually cross suture lines

Answer 22

FALSE: Hemorrhage results form venous injury most commonly

Lentiform shaped, so epidural hematoma. Usually caused by middle meningeal artery laceration from skull fracture; often presents with lucid interval; and doesn’t cross suture lines.

Question 23

Which is true of the CT scan?

• This most commonlyr esults from tearing of the middle meningeal artery
• This is a chronic hemorrhage
• The hemorrhage does not cross suture liens
• This most often results from tearing of briding veins that drain into the superior sagittal sinus

Answer 23

This is crescent shaped, so it’s subdural hematoma, which results from tearing of bridging veins that drain into the superior sagittal sinus