Neuro Ophthalmology

Neuro-ophthalmologyfor

Medical StudentSurat Tanprawate, MD, MSc(London), FRCP(T)

Neurology Unit, Department of MedicineChiang Mai University

Wednesday, October 31, 2012

The scope of Neuro-ophthalmology

• Oculomotor system

• conjugate eye movement

• Saccadic system

• Pursuit system

• Vergence system

• Counter rolling system: VOR, Ocular fixation system

• Visual perception system

• Eyelids

• Pupils





• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils

Disconjugate eyes: diplopia





• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils


Visual loss





• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils


Visual loss

Ptosis





• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils


Visual loss

Ptosis

Anisocoria


Oculomotor pathway

• Supranuclear(UMN)• FEF: horizontal conjugate gaze• Diffuse frontal and occipital:

vertical conjugate gaze• Nuclear (LMN)

• CN III, IV, VI• Internuclear

• PPRF, abducen interneuron, MLF (Horizontal gaze)

• riMLF, INC, PC (Vertical gaze)• Infranuclear(LMN)

• Faciculus• Cranial nerve• NMJ• muscle


Frontal eye fields


Frontal lobe lesion: no diplopia- Destructive FEF lesion: • eyes deviate to the lesion

- Excitatory lesion: • eyes deviate to contralateral to the lesion

Right frontal lobe infarct


Diplopia (double vision)

• Diplopia is the simultaneous perception of the two images of a single object that may be displaced horizontally, vertically, diagonally

• caused by impair EOMs functions

pic from wikipedia


DiplopiaMonocular

diplopiaBinocular diplopia

Repetitive images

Ghosting image

- Cerebral polyopia- Non-organic

- Retinal disease- Refractive error

Misalignment of the eyes

Nuclear control

Internuclear control

Infranuclear control

- CN III- CN IV- CN VI

- CN palsy- NMJ disorder- Muscle disorder

Horizontal diplopia- INO- PPRFVertical diplopia- INC, riMLF


Key features• Nuclear and fascicular lesion

• Brain stem sign: long tract sign, other CN involvement

• Nerve lesion

• Neighborhood sign; other CN, other sign

• Internuclear lesion

• specific syndrome; Internuclear Ophthalmoplegia (INO), WEBINO, One and a half syndrome

• NMJ lesion: fatiguability, not consistent with CN lesion, sign of myasthenia gravis

• Muscle lesion: not consistent with CN lesion: not consistent with CN lesion, sign of myopathy


The action and nerve supply of the extraocular muscles is demonstrated.


Nuclear and nerve lesion


The oculomotor nerve (cranial nerve III)

CN III


The course of the trochlear nerve in the pons

CN IV


facial nerve wraps around the nucleus of cranial nerve VI within the pons

CN VI


A woman with acute diplopia for 2 weeks



Right LR palsy; No other neurological sign, MRI brain-normal



Right LR palsy; No other neurological sign, MRI brain-normal

“Pure Right CN VI palsy”Wednesday, October 31, 2012

A 55 Y.O. with DM, HT presented with acute diplopia for 2 days



Left LR palsy



Left LR palsyDx. “Left CN VI palsy from ischemic neuropathy”


Bilateral LR could be pseudo sixth nerve palsy from IICP


Third nerve palsy


Multiple oculomotor nerve involvement

• Cavernous sinus syndrome

• Superior orbital fissure syndrome


19

Cavernous sinus syndrome

• Association with – other cranial nerve

involvement: 4, 5, 6 CN – oculosympathetic paralysis– Opthalmic branch of trigeminal

nerve• Tend to be partial; alls

muscles innervated are not equally involved


20

Superior orbital fissure syndrome

CN 3, 4, 6, V1Wednesday, October 31, 2012

21

Superior orbital fissure syndrome

• Involve CN 3, 4, 6 and V1 CN 5 distribution +/- oculosympathetic paresis without anhydrosis

• May exopthalmos due to blockade of the opthalmic veins

• Blindness due to extension of the pathologic process to involve the optic canal


A patient with diplopia for 1 week with gait ataxia and areflexia

2 weeks 2 months



2 weeks 2 months

in a patient with polyneuropathy, all CN can be involved causing total ophthalmoplegia



2 weeks 2 months

in a patient with polyneuropathy, all CN can be involved causing total ophthalmoplegia

Dx. Miller Fisher syndrome


Interneuclear lesionInterneuclear ophthalmoplegia (INO): MLF lesionBilateral INO : Bilateral MLF lesionOne and a half syndrome: PPRF lesion + MLF lesion


Unilateral MLF lesion• “ internuclear

ophthalmoplegia “• Ipsilat. MR weakness• Ipsilat. abducting

saccade• Contralat. adducting

nystagmus• Dissociated nystagmus


Interneuclear ophthalmoplegia (INO)

c. Normal left abduction on left gaze

d. Normal convergence

a. Normal primary position

b. Left impaired adduction on right gaze and horizontal nystagmus of the right eye


Bilateral MLF lesion

• Bilateral MLF lesion–Bilateral adducting weakness–Bilateral abducting nystagmus–Impaired vertical vestibular and pursuit –Impaired vertical gaze holding–Gaze evoked nystagmus

• Wall eyed bilateral INO : WEBINO–exotropia


A man with sudden diplopia

WIBINOWednesday, October 31, 2012

One and a half syndrome• Combined lesion :

PPRF and MLF• “ One and a half

syndrome “–Ipsilateral horizontal gaze

palsy–INO



Infranuclear lesion ;

disease of ocular muscledisease of NMJ


Total ophthalmopathy in CPEO patient


TRIO with Bilateral ptosis (MG)


• Upper eyelid– Levator palpebral

superioris(CN 3)– Muller muscle

(sympathetic)– Frontalis muscle(CN 7)

• Lower eyelid– Capsulopalpebral fascia

(inferior rectus)– Inferior tarsal muscle

(sympathetic)


Ptosis

Neurologic ptosis

Non-neurogenic(mechanical) ptosis

•Uni-bilateral•Partial-complete

•Pupil involvement•EOM impairment

Supranuclear lesion(cerebral ptosis)•Contralateral cerebral hemisphere

LMN•Neuropathic(N, fascicle, CN)•NMJ•Myopathic

Congenital ptosis

Horner’s syndrome


Ptosis from Cranial nerve III lesion

- complete or near complete ptosis

- EOM involvement

- Pupil dilatation


MG with enhancing ptosis

Ptosis due to NMJ lesion: sign of fatiguability


Nystagmus


Nystagmus• Ancient Greek (nustagmos (Ancient

Greek, "nodding, be sleepy")

• Involuntary biphasic rhythmic ocular oscillation in which one or both phase are slow

• The slow phase is responsible for the initiation and generation of the nystagmus, whereas the fast (saccadic) phase i a corrective movement bringing the fovea back on target

• Type: jerk (direction to fast phase) ; pendular nystagmus


Mechanism

• Nystagmus may result from dysfunction of the vestibular ending organ, vestibular nerve, brainstem, cerebellum, or cerebral centers for ocular pursuit


In (A) a slow phase is followed by a slow phase while in (B)–(D) a slow phase is followed by a fast phase

A schematic illustration of nystagmus waveforms

(A) pendular nystagmus

(B) an accelerating velocity exponential slow phase jerk nystagmus (CN)

(C) a decelerating exponential slow phase jerk nystagmus (MLN)

(D) a linear or constant velocity slow phase jerk nystagmus (MLN)


Mechanism

• Pendular nystagmus: is central (brainstem/cerebellum)

• Jerk nystagmus:

• linear (constant velocity) slow phase: peripheral vestibular dysfunction

• slow phase has decreasing velocity exponential: brainstem neural integrator

• slow phase has increasing velocity exponential: central in origin (usual form of congenital nystagmus)


A woman with periodic vertigo occur when changing position

“vestibular nystagmus”Wednesday, October 31, 2012

case study: a boy with subacute dizziness



Conclusion



• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils


Conclusion



• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils



Conclusion



• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils


Visual loss


Conclusion



• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils


Visual loss

Ptosis


Conclusion



• Saccadic system

• Pursuit system

• Vergence system



• Eyelids

• Pupils


Visual loss

Ptosis

Anisocoria


Thank you for your kind attention


The NeurologistCMU


Documents

Neuro Ophthalmology