Clinical Neuro-Ophthalmology

Surat Tanprawate, MD, MSc(London), FRCP(T)!Neurology Unit, Department of Medicine!Chiang Mai University

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

Disconjugate eyes: diplopia

Visual loss

Ptosis

Anisocoria

Anisocoria

Oculomotor pathway

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

vertical conjugate gaze!• Nuclear (LMN)!

• Nerve III, IV, VI Nucleus!• Internuclear!

• PPRF, abducen interneuron, MLF (Horizontal gaze)!

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

• Fasciculus!• Cranial nerve!• NMJ!• Muscle

Frontal eye fields

Frontal lobe lesion: no diplopia!- Destructive to FEF lesion: !

• eyes deviate to the lesion!- Destructive to Pontine lesion:!

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

• eyes deviate contralateral to the lesion

Right frontal lobe infarct

Case

Dysconjugate eyes

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!- PPRF!Vertical diplopia!- INC, riMLF

IIIIV

VI

Nuclear and Internuclear control

Vertical gaze internuclear control

Horizontal gaze internuclear control

Nuclear control: Nucleus III, IV, VI

Infranuclear control

Fasciculus

Nerve

NMJ

Muscle

Key featuresNuclear and fascicular lesion!

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

Nerve lesion!

• Neighbourhood 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

Isolated CN III palsy with sparing pupil

Cause of oculomotor nerve palsy

• Common: vasculopathy (diabetes, atherosclerosis, aneurysm), tumor!

• Less common: inflammation, cavernous sinus thrombosis

A woman with acute diplopia for 2 weeks

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

“Pure Right CN VI palsy”

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

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

Bilateral LR could be pseudo sixth nerve palsy from IICP

Cause of CN VI palsy

• Most common: vasculopathy (diabetes, hypertension, atheroscleosis), trauma, idiopathic, IICP!

• Less common: giant cell arteritis, cavernous sinus lesion, multiple sclerosis, vasculitis, stoke

Posterior communicating artery aneurysm causing CN III palsy

Multiple nerve involvement

• Cavernous sinus syndrome!

• Superior orbital fissure syndrome

!29

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

!30

Superior orbital fissure syndrome

CN 3, 4, 6, V1

!31

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

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

Dx. Miller Fisher syndrome

Interneuclear lesion

Interneuclear ophthalmoplegia (INO): MLF lesion!Bilateral INO : Bilateral MLF lesion!One and a half syndrome: PPRF lesion + MLF lesion

Horizontal

Unilateral MLF lesion• “ internuclear

ophthalmoplegia “!• Ipsilateral MR weakness

ipsilateral side!• Contralat. abducting

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

WIBINO

One and a half syndrome• Combined lesion :

PPRF and MLF!• “ One and a half

syndrome “!–Ipsilateral horizontal gaze

palsy!–INO

Bilateral PPRF lesion

• Bilateral horizontal gaze failure!

• Sparing vertical gaze!

• Sparing pupil!

• May combine with other brain stem sign

A woman with diplopia and facial palsy

Interneuclear lesion

Upward and downward gaze failureVertical

Vertical gaze control

Cause of internuclear lesion

• Common: demyelination (multiple sclerosis), brainstem infarction!

• Less common: tumor, infection

Infranuclear lesion ; !

disease of NMJ !disease of ocular muscle

Neuromuscular Junction

Features of NMJ disorder

• Ophthalmoplegia is not consistent with nerve distribution!

• Fatigue!

• Fluctuating course!

• with other muscle weakness esp. ptosis, proximal muscle weakness

A patient with diplopia and ptosis

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 centre for ocular pursuit

Peripheral vs Central nystagmus

• Severe vertigo

• Minute to Day to weeks duration

• Hearing loss, tinnitus associated

• Usually horizontal with torsion

• Very rarely purely vertical or torsional

• Commonly peripheral vestibular organ dysfunction: labyrynthitis, meniere’s disease

• None or mild vertigo

• Often chronic

• May be purely vertical or torsional

• Visual fixation usually has no effect

• Downbeat, upbeat, torsional

• Etiologies commonly vascular, demyelination, pharmacologic, toxic

Peripheral nystagmus Central nystagmus

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, cerebellar!

• 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”

Case study: a boy with subacute dizziness

Conclusion

• Oculomotor system!

• conjugate eye movement!

• Saccadic system !

• Pursuit system!

• Vergence system!

• Counter rolling system: VOR, Ocular fixation system

• Visual perception system!

!

• Eyelids!

• Pupils

Disconjugate eyes: diplopia

Visual loss

Ptosis

Anisocoria

The Neurologist CMU

The Neurologist CMU

Thank you for your kind attention