Cranial nerves +Lesions

Question 1

location of defect in unilateral field loss, bitemporal hemianopia(left loss on left, right loss on right, homonymous hemianopia (both right side visual field loss)

Answer 1

unilateral- left optic nerve compression
Bitemporal- Chiasamal compresion
Homonymous- left optic tract

Question 2

aetiology of diseases of optic nerve (3)

Answer 2

Trauma, tumor, Ischemia

Question 3

symptom triad of optic neuritis

Answer 3

loss of vision, eye pain, impairment of accurate color

Question 4

what is the inn of the CN3

Answer 4

somatic-
Lev palpebral
sup rectus
medial rectus
inf rectus
inf oblique

Visceral motor-
Pupil constriction (constrictor pupillae, cilliary)

Question 5

What is the ciliospinal reflex

Answer 5

see pupillary dilation when a noxious stim is applied to the face, head, nape of neck

Question 6

What does the accommodation test

Answer 6

Test the neural circuit from retina CN2 to parasympathetic component CN3

-stims smooth mm of ciliary body to contract

Question 7

Features of Cn3 Lesion

Answer 7

eye deviated down and out
diplopia
dilated non reactive pupil
loss of accomidation
ptosis (weak lev palpebral)

Question 8

CN4 function and pathological features

Answer 8

motor to superior oblique mm
–Inward rot, depresses, abducts globe

Patient tilt head toward unaffected eye to overcome inward rotation of affected eye

Question 9

CN5 tests

Answer 9

corneal reflex, facial sensation

mm- clench teeth and palpate massester

jaw jerk

Question 10

Convergance theory for spinal pain transmission

Answer 10

Convergence of sensory input from upper 3 cervical segments and the trigeminocervical nucleus as a pain generator

Question 11

features of abducens palsy

Answer 11

inability to move eye laterally

Diplopia on lateral gaze

Question 12

facial nerve function (7)

mm, parasympathetic, Sensation

Answer 12

mm to muscles of facial express
Stim of lacrimal, submandibular and sublingual glands
sensation ant 2/3 of tongue, ear canal, tympanic membrane

Question 13

peripheral vs supratentorial facial nerve lesion

Answer 13

supra- just lower or upper

Peripheral- Full upper and lower

Question 14

valsalva open vs closed what it testing

Answer 14

Open glotis- pressure in ear canal

Closed glotis- more abdominal pressure

Question 15

glossopharyngeal nerve function

Answer 15

general sensation and taste to post 1/3 of tongue

motor supply to stylopharyngeal

Question 16

UMN vs LMN lesion hypoglossal nerve

Answer 16

UMN- Contralateral weakness

LMN- Ipsilateral weakness