Anatomy

Question 1

What is the pathway in which CSF flows?

Answer 1

CSF is produced by the choroid plexus → lat ventricles → foramen of Monroe → 3rd ventricle → cerebral aqueduct of Sylvius → 4th ventricle → foramen of Magendie, and 2 lat foramina of Lushka

Question 2

Which structures enhance on the MRI sequences, T1, T2, and FLAIR?

Answer 2

T1 enhances fat and ST, does not enhance fluid. T1 with contrast is generally the best way to visualize intracranial tumors. T2 enhances fluid (CSF, edema) and does not enhance fat. FLAIR removes the increased CSF signal on T2 and shows abnl fluid (masses and edema).

Question 3

Which structures enhance with contrast?

Answer 3

Mets, Abscess, GBM, Lymphoma, +/– AA or AO [anaplastic astrocytoma/anaplastic oligodendroglioma]) (Mnemonic: MAGLA), meningioma, pilocytic astrocytoma, gliosis, cerebritis

Question 4

Which structures do not enhance with contrast?

Answer 4

Grade 2 low-grade gliomas, +/– AA or AO, rare for GBM to not enhance.

Question 5

Which gyri contain the sensory and motor area?

Answer 5

The precentral gyrus contains the motor area, and the postcentral gyrus contains the somatosensory area. Medial = body, LEs, feet. Lat = trunk, arms, head.

Question 6

What brain region is associated with expressive aphasia?

Answer 6

The Broca motor area (dominant/left frontal lobe) is associated with expressive aphasia.

Question 7

What brain region is associated with receptive aphasia?

Answer 7

The dominant/left temporal lobe at the post end of the lat sulcus (Wernicke area) is associated with receptive aphasia.

Question 8

Which CN exits on the dorsal side of the brain (midbrain)?

Answer 8

CN IV exits on the dorsal side of the brain.

Question 9

What structures are in the cavernous sinus?

Answer 9

CNs III, IV, VI, V1, and V2; internal carotid artery

Question 10

What common defect does tumor involving the cavernous sinus produce?

Answer 10

CN VI palsy (no abduction of the lat rectus)

Question 11

What components traverse the sup orbital fissure?

Answer 11

CNs III, IV, VI, and V1

Question 12

What nerve passes through the foramen rotundum?

Answer 12

V2 passes through the foramen rotundum.

Question 13

What nerve passes through the foramen ovale?

Answer 13

V3 passes through the foramen ovale.

Question 14

What structures pass through the foramen spinosum?

Answer 14

The middle meningeal artery and vein as well as the nervus spinosus (branch of CN V3), pass through the foramen spinosum.

Question 15

Through what structure do CNs VII–VIII traverse?

Answer 15

CNs VII–VIII traverse through the internal auditory meatus.

Question 16

Through which foramen does CN VII traverse the skull base?

Answer 16

CN VII emerges through the stylomastoid foramen.

Question 17

What passes through the jugular foramen?

Answer 17

CNs IX–XI pass through the jugular foramen.

Question 18

How many spinal nerves are there in the SC?

Answer 18

There are 31 spinal nerves in the SC (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal).

Question 19

Where does the cord end? Where does the thecal sac end?

Answer 19

The cord ends at L3–4 in children and L1–2 in adults. The thecal sac ends at S2–3 in both children and adults.

Question 20

What tumors present with a dural tail sign?

Answer 20

Meningioma (60%), also chloroma, lymphoma, and sarcoidosis