CRACK Flash

Question 1

Name some ways you can find the central sulcus?

Answer 1

• “pars bracket sign” - bi-hemispheric symmetric pars marginalis forms an anteriorly open bracket; the bracik is immediately behind the central sulcus
• Superior frontal sulcus / Pre-central sulcus sign
• Bifid post-central sulcus
• intraparietal sulcus intersects the post-central sulcus
• Inverted omega sign on the central sulcus
• Midline sulcus sign - most prominent sulcus that reaches the midline is the central sulcus

Question 2

Name the cavum variants

Answer 2

1. Cavum septum pellucidum
2. Cavum vergae
3. Cavum velum interpositum (extension of quadrigeminal plate cistern to foramen of monroe.

Question 3

Sites of CSF production

Answer 3

1. Lateral ventricles (body and temporal horns!)
2. Roof of 3rd ventricle
3. Roof of 4th ventricle

Question 4

Name the basal cisterns

Answer 4

1. Anterior interhemispheric fissure
2. Sylvian cistern
3. Ambient (paramesancephalic) cistern
   
   1. bridge between interpeduncular and quadrageminal cistern
4. Quadrageminal plate cistern

Question 5

Skull Foramen - contents

• Foramen Ovale
• Foramen Rotundum
• Superior Orbital Fissure
• Inferior Orbital Fissure
• Foramen Spinosum
• Jugular Foramen
• Hypoglossal canal
• Optic Canal
• Cavernous Sinus
• IAC
• Meckel’s Cave
• Dorello’s Canal

Answer 5

• Foramen Ovale = CN V3 (and accessory meningeal artery)
• Foramen Rotundum = CN V2 (R2V2I2)
• Superior Orbital Fissure = CN 3, 4, 6 and V1
• Inferior Orbital Fissure = CN V2
• Foramen Spinosum = Middle meningeal artery
• Jugular Foramen = Pars Nervosa (CN 9 + Jacobson’s (tympanic branch nerve) and Pars Vascularis (CN 10, 11 and Auricular Arnold’s Nerve)
• Hypoglossal canal = CN 12
• Optic Canal = CN 2 and opthalmic artery
• Cavernous Sinus = Everything in superior orbital fissure + V2
• IAC = CN 7 and 8 (cochlear, inferior vestibular and super vestibular components) “7 UP, Coke Down
• Meckel’s Cave = Trigeminal ganglion (and CSF)
• Dorello’s Canal = CN (abdu)6, inferior petrosal sinus

Question 6

What are the segments of the ICA?

Answer 6

“CPLCCSC”

• C1 Cervical
• C2 Petrous
• C3 Lacerum
• C4 Cavernous
• C5 Clinoid
• C6 Supraclinoid (Ophthalmic)
• C7 Communicating

Question 7

CN3 Palsy - what artery is the culprit?!

Answer 7

PCOM Aneurysm

Question 8

Anatomotic veins of trolard and labbe

Answer 8

Trolard = on Top (connects the middle cerebral vein and super sagittal sinus)

Labbe = Lower (connects superficial middle cerebral vein and transverse sinus)

Question 9

Basal vein of Rosenthal

Answer 9

Paired deep veins that pass lateral to the midbrain through the ambient cystirn and drains into the vein of Galen (course similar to PCA)

This is more lateral relative to the Internal cerebral veins

Question 10

Internal cerebral veins

Answer 10

The internal cerebral veins are paired, paramedian veins which course posteriorly along the roof of the third ventricle, between the two leaves of the velum interpositum.

Each is formed at the foramen of Monro by the confluence of the choroidal vein (draining the choroid plexus of the lateral ventricle), and the thalamostriate vein (which lies in the groove between the thalamus and caudate nucleus and receives blood from both). The veins of the septum pellucidum usually join the thalamostriate vein.

Question 11

What are the 5 big congentital malformation groups?

Answer 11

1. Failure to form
   
   1. Corpus callosum dysgenesis
   2. Open neural tube defects (ie anencephaly)
   3. cerebellar vermis (ie rhombencephalosynapsis)
   4. dandy-walker
2. Failure to cleave
   
   1. Holoprosencephaly - septo-optic dysplasia
3. Failure to migrate
   
   1. Band heterotopia etc
4. Failure to organize
   
   1. Polymicrogyria, schizencephaly
5. Herniation syndromes
   
   1. Chiari malformations
6. Mimicks = porencephalic cysts, hydranencephaly, severe hydro