Neuro-Opthamology

Question 1

There are conventionally ____ pairs of cranial nerves

Answer 1

12

Question 2

With the exception of CNs ___________ , all nuclei are present in the ___________.

Answer 2

I and II

Brain stem

Question 3

Location of the Nucleus : Cranial Nerves

Base of the Fore brain

Midbrain

Pons

Medulla

Answer 3

CN I, CNII

CN III, CN IV

CNV, CNVI, CN VII, CN VIII

CN IX, CN X, CN XI, CN XII

Question 4

Optic nerve

It carries approximately ________ afferent fibres which originate from the ____________________.

Most synapse in the _________________

Answer 4

1.2 million

Retinal Ganglion Cells(RGCs)

Lateral Geniculate Body(LGB).

Question 5

The optic nerve fibres are divided into about _________ bundles by fibrous septae derived from the ________

Answer 5

600; pia mater

Question 6

Optic nerve

Nearly ________ of the fibres subserve the central 5 degrees of the visual field.

The optic nerve is approximately ______ long from the globe to chiasm.

Divided into 4 segments: _____,_____,______,_______

Answer 6

one-third

50mm

Intraocular
Intraorbital Intracanalicular Intracranial

Question 7

VISUAL PATHWAY

List them

Answer 7

Optic nerves
Optic Chiasma
Optic tracts
Lateral geniculate bodies\ Optic radiations
Occipital cortex

Question 8

Anatomy of the visual pathway

From the chiasm, the visual pathway continues into the __________
Fibres in the optic tracts synapse in the _______________ (above or below?) the ___________

The pathway continues in the _________ to the ________________

Visual defects from now on affect the same side of vision in both eyes and are therefore homonymous

Answer 8

optic tracts

lateral geniculate body; below

thalamus; visual radiations

occipital cortex

Question 9

Pupillary pathways

________ reflex
_______ reflex
Pupillary _________
Psychosensory reflex

Answer 9

Light

Near

dilatation

Question 10

Light reflex pathway

1.AFFERENT PATHWAY
The _______ segment of the ______________ are the receptors for both visual pathway and light reflex.

2)EFFERENT PATHWAY: Preganglionic parasympathetic myelinated fibres go to the _____________ via CN ______ .
The postganglionic myelinated fibres pass through __________ nerves to innervate the __________ pupillae.

Answer 10

outer; rods and cones

ciliary ganglion ; III

short ciliary; sphincter

Question 11

Near Reflex Pathway

Near reflex occurs on looking at a near object.

Near reflex triad : ___________,__________ and _____________

Answer 11

accommodation, convergence and constriction.

Question 12

Near Reflex Pathway

Convergence reflex comprises of convergence of the __________ of the eyes with associated _______________.

Consists of the afferent pathway which begins at the _________ and the efferent pathway which is similar to that of the ______________

Answer 12

visual axes

constriction of the pupil

medial recti

efferent light reflex

Question 13

Pupillary dilatation pathway

______pathetic pathway and begins in the ____________________.

Answer 13

sym

posterior hypothalamus

Question 14

Causes of Lesions of the visual pathway

List 5

Answer 14

Trauma
Tumour
Vascular lesion
Inflammation
Degeneration

Question 15

Damage to the oculomotor nerve (III) can cause _______ vision and inability to coordinate the movements of both eyes (__________), also ______________ and _________________.

Lesions may also lead to inability to open the eye due to ________________

Answer 15

double; strabismus

eyelid drooping (ptosis) and pupil dilation (mydriasis)

paralysis of the levator palpebrae muscle.

Question 16

Individuals suffering from a lesion to the oculomotor nerve may compensate by _______________ to alleviate symptoms due to paralysis of one or more of the eye muscles it controls

Answer 16

tilting their heads

Question 17

Damage to the trochlear nerve (IV) can also cause double vision with the eye _______ and ____________. The result will be an eye which can not move ______wards properly (especially ______wards when in an _________ position). This is due to impairment in the superior oblique muscle

Answer 17

adducted; elevated

down; down

inward

Question 18

AMAUROTIC PUPIL

______________ pupillary defect.
Caused by a ________________________ or _____ lesion leading to _________ on the affected side.

The VA is _________.

Answer 18

Total afferent

complete optic nerve or retinal

total blindness

NPL

Question 19

AMAUROTIC PUPIL

Affected pupil neither _____________ nor does it _________________________, however it has a good consensual light reflex from stimulation of the contralateral eye.

Afferent = ______. Efferent = ________

Answer 19

reacts to a direct light

create a consensual pupillary light reflex

lesion; normal

Question 20

MARCUS GUNN PUPIL
____________ pupillary defect.
Best tested by _______________ test.

A paradoxical response whereby the affected pupil dilates when _________________________________ .

Answer 20

Relative afferent

swinging flash light

light is moved from the normal eye to the abnormal eye

Question 21

MARCUS GUNN PUPIL

Grades :
1=______ constriction and ______ redilatation.
2= _________ and _______ redilatation
3= __________ dilatation
4= ______________ dilatation following ______________________
5= ___________ dilatation with _____________ constriction at all.

Answer 21

weak; greater

initial stall and greater

immediate

immediate pupillary; illumination of good eye for 6 seconds.

immediate; no secondary

Question 22

WERNICKE’S HEMIANOPIC PUPIL

Indicates a lesion in the ________.
Light reflex is absent when light is thrown on the __________ half of the retina of affected eye and the ________ part of the retina on the unaffected eye.

Patient also has _____________

Answer 22

optic tract

temporal; nasal

homonymous hemianopia.

Question 23

ARGYLL ROBERTSON PUPIL

Classical finding in __________
Mostly seen in people with Tabes dorsalis i.e. syphilitic myelopathy – demyelination of nerves primarily in dorsal column of spinal cord.

Answer 23

neurosyphilis

Question 24

ARGYLL ROBERTSON PUPIL

Lesion in the region of the _______________, ________ area and rostral midbrain dorsal to the _____________ where there is also disturbance of the normal inhibitory pathways from the reticular activating system upon the parasympathetic EW subnucleus.
Other causes include diabetes, midbrain lesions.

Answer 24

aqueduct of sylvius

pretectal; EW nucleus

Question 25

TONIC PUPIL (Adie’s pupil)

Light-near dissociation; near accommodation produces more ________ compared to ______________.

Damage to the parasympathetic __________ or ______________  denervation supersensitivity of iris sphincter whereby postsynaptic receptors are upregulated to aid reinnervation  aberrant reinnervation with fibres intended for ciliary body targeting the pupil  light-near dissociation.

Notable syndromes associated with tonic pupil include Holmes-Adies syndrome, Ross syndrome, Riley Day syndrome

Answer 25

miosis; response to light

ciliary ganglion; short ciliary nerves

Question 26

HORNER’S SYNDROME

Lesion of the sympathetic system characterized by ________,____________, and _______________ on the affected side.

Answer 26

miosis, partial ptosis and anhydrosis

Question 27

HORNER’s Syndrome

Ptosis- mild or moderate, due to _________________.

Miosis- moderate miosis with dilatation lag, due to _________________

Facial anhydrosis-____________ on ipsilateral face and neck, usually occurring in the preganglionic type.

Heterochromia iridis can occur in congenital Horner’s syndrome where ________________________ fail to develop.

Answer 27

paralysis of Muller’s muscle

unopposed action of the sphincter pupillae following paralysis of the sympathetically innervated dilator pathway.

reduced sweating

iris pigment of the stroma