Neuroanatomy

Front 1

What happens when you have a ruptured ICA in the cavernous sinus? Or orbital trauma?

Back 1

You have an abnormal communication between the arteries and vein known as carotid cavernous fistulas.
Two types. first type is "classic carotid cavernous fistula high pressure, high volume leading to chemosis and lid endema, orbital bruit, increase IOP, engorged episcerlal vein. This type is most likely due to trauma.
Second type is low flow low pressure knowned as dural cavernous fistula where it just leaks a little bit. 50% chance of spontaneous resolution. Both types need neurological consults.

Front 2

When you think the patient has chronic conjunctivitis, and you have engorged, cork-screw episcleral vessels, you have to think about this as a ddx ...

Back 2

You have to think about dural cavernous fistula. This post-ICA aneurysm condition often mimics chronic conjunctivitis (due to eyes' redness, but NO discharges). You will see cork-screw blood vessels on conj, pulsatile mires on GAT, and possible VI involvement due to its proximity to ICA. Need to send patient out for neuro consult and imaging.

Front 3

What is the main differences between classic cavernous fistula and dural cavernous fistula?

Back 3

In classic carotid cavernous fistula, there's a BIG RUPTURE of the vessels causing backing up of venous outflow, often due to trauma to the orbit. THIS IS AN EMERGENCY REFERAL for imaging. In dural cavernous fistula, there's a SMALL TEAR in the blood vessels, with 50% chance of spontaneous resolution. NOT URGENT, but still need neuro imaging.

Front 4

What's the differences between a PCA (posterior communicating aneurysm) and an ICA aneurysm in term of location and cranial nerves involvement?

Back 4

PCA happens in the sub-arachnoid space affecting CN III and there's pupil involment.
ICA aneurysm happens in the cavernous sinus, causing Carotid cavernous fistulas or dural cavernous fistula when ruptured, and ICA aneurysm most likely affecting CN VI when not ruptured yet. There may or may not be pupil involvement.

Front 5

IF you see Horner's syndrome and EOM involvement, what do you need to r/o?

Back 5

Cavenous sinus aneurysm. Imaging.

Front 6

If you see unilateral small pupil which does not react to far AND near, what could it be? Could it be an APD?

Back 6

Cavernous sinus aneurysm.

Front 7

Which CN is most likely to be affected by pituitary adenoma? ICA aneurysm? Why?

Back 7

Pituitary adenoma most commonly affects CN III. ICA aneurysm commonly affects CN VI. both due to anatomical proximity.

Front 8

How do you dx Tolosa Hunt Syndrome?

Back 8

By dx of exclusion. "Tolosa Hunt is an idiot whose sinus is inflamed" . Idiopathic granulomatous inflammation of the cavernous sinu. all CN plus the oculosympathetic pathway could be affected. Therefore, dx of occlusion. Response well to oral steroid.

Front 9

What CN run alongs the floor of the middle cranial fossa?

Back 9

I THINK CN V. not sure though

Front 10

IF you have a complete V palsy, what do you think about?

Back 10

MS, midle cranial fossa dz, tumor, nasophryngeal carninoma, brainstem.

Front 11

What CN does Raeder's Trigemenial neuralgia affect?

Back 11

CN V1, the ophthalmic branch. Raeder is basically a PAINFUL (migranous headache) ipsilateral horner syndrome.

Front 12

Herpes zoster can affect the cornea if this CN is affected?
percentage of ocular involment in herpes zoster?

Back 12

CN V1, the naso ciliary branch of the ophthalmic branch of V1.
2/3 with eye involvment.

Front 13

Patient reports brief pain that feels like burning matches, or lighting, touching their face. what is it and what CN is affected?

Back 13

Trigeminal neuralgia (Tic douloureaux) and it can affects all three V1,2,3. V1 is least common.

Front 14

Patient has transient pain of the face and their face feels full. Que es?

Back 14

Sinusitis affecting CN V1.

Front 15

If patient says she has Bell's palsy on the left side, what do you expect to find on your CN testing?

Back 15

The patient left lower face will be palsied because of mono-innervation by the upper motor neuron, while the upper face will be ok due to dual innervation. the cause is with the RIGHT upper motor neuron (lesion). Her smile will be crooked with the absent of nasolabiac fold on the left. Laughing will be normal since laugh is involuntary.

Front 16

if you have palsy of both the lower and upper face, what do you think of?

Back 16

Lower motor neuron lesion.

Front 17

If you have hemiparesis and ipsilateral facial paralysis, where is the lesion?

Back 17

Lesion is in the CONTRALATERAL motor cortex or internal capsule.

Front 18

if you have hemiparesis and CONTRALATERAL facial paralysis, where is the lesion?

Back 18

Facial Nucleus (CN VII) or pons. Not sure why.