EYES IN FINALS SHORTS TAGGED ON TO NEURO EXAM TINY PROPORTION OF THE MARKS Can make you look really...

EYES IN FINALS

• SHORTS• TAGGED ON TO NEURO EXAM

• TINY PROPORTION OF THE MARKS• Can make you look really clever

• RELAX

Neuro-ophthalmology for finals

Tom Marjot

To do…

• Pupillary abnormalities• Horners syndrome• Eye movements and Ophthalmoplegia• Visual field defects • Special cases– Multiple Sclerosis– Myasthenia gravis– Cerebellar disease

Relative Afferent Pupillary Defect

Rehearse! – come up with your own script

“Stimulation of the normal eye produces full constriction of both pupils – both direct and consensal reflexes are intact”

“Subsequent stimulation of the affected eye causes dilatation of both the pupils”

“This is because the consensual pathway from the normal eye (which is now in darkness) is stronger than the afferent

pathway from the pathological eye”

Pupillary abnormalities

Relative Afferent Pupillary Defect

…“These findings are consistent with a RAPD…otherwise known as a Marcus Gunn Pupil”

REMEMBER:If you pick up a pen-torch in finals it is synonymous with “I am looking for a RAPD”

Difference in pupil size in all other pathologies (Horners, oculomotor palsy, brainstem herniation) will NOT require a pen torch.

….. When I shine a light in the eye does the pupil dilate?

“What are the causes of RAPD?......”“Disorders of the optic nerve

Or Disorders of the Retina… I would therefore like to perform fundoscopy

Optic nerve:Optic neuritis/atrophy – Multiple Sclerosis

Retina:Retinal detachment, retinal vein or artery occlusion, severe diabetic retinopathy

“RAPD there must be a difference in the extent of the disease between the two eyes”

RAPD

• Have a script

• Pen-torch = RAPD = does pupil dilate when I shine a light?

• Afferent pathway involves - nerve or retinal

• Offer fundoscopy

Unequal pupils

A starting point:• Don’t need a pen-torch• Look carefully• Smaller = ‘miotic’ Larger = ‘mydriatic’• Unequal = “Anisocoria”

“The patient has marked anisocoria with a left miotic pupil”

“The is also a visible (partial) left sided …………..Ptosis”

“This gives the impression of apparent enophthalmos”

“These findings would be consistent with a left Horners Syndrome”

So you’ve landed at Horner's Syndrome (Correctly)

Now sit and wait for the questions or you can be proactive.

Remember your differentials- You have discovered and commented on a ptosis- State that you would like to check for ophthalmoplegia (eye movements)

because Myasthenia gravis and Oculomotor nerve pasy also give a ptosis.

No opthalmoplegia and given the clearly miotic left pupil – Horner’s Syndrome.

Silly because impossible to accurately clinically determine but important for exams ………

Pattern of ANHIDROSIS

1

2

3More peripheral the lesion the less sweating is affected

1 - Face, arm and trunk2 – Face3 – Not affected

ANHIDROSIS

1

2

3 Central or Peripheral lesions Horner’s

CentralDemyelinationTumour

PeripheralPancoast tumourCervical ribNeck/cardiothoracic surgery

Unilateral ptosis1. Horners syndrome2. III nerve Palsy3. Myasthenia Gravis

Bilateral ptosis4. Myasthenia Gravis

Heterochromia

Associated with congenital Horners

• Ptosis + miosis

• Remember ptosis differentials and check eye movements

• Causes can be central or peripheral

Horner’s Syndrome

“The patient has a complete left sided ptosis”

Unilateral ptosis1. Horners syndrome2. III nerve Palsy3. Myasthenia Gravis

“There is also marked aniscocoria with a mydriatic pupil on the left”

“There is a left divergent stabismus at rest…. With the eye fixed in a down and out position”

“These findings would be consistent with a left III cranial nerve lesion”

“Due to pupillary involvment this could be said to be a ‘surgical’ III nerve palsy”

Superior Oblique - IVLateral Rectus - VI

• Levator Palpebrae Superioris – CNIII• Mullers Muscle - Sympathetic

SurgicalExternal compressive lesion impinging on parasympathetic fibres which run very superficially in the nerve trunk

- Tumour- Haemorrhage- Aneurysm – (Posterior Communicating Artery Aneursym)

Medical- Diabetes

AnatomicallyBrainstem: Tumour, infarct haemorrhage, demyelinationCavernous sinus lesion: Tumour, thrombosisSuperior orbital fissure: Trauma

• Ptosis +/- mydriasis• Divergent strabismus at rest

• Opthalmoplegia

• Medical vs Surgical may help you list causes

Oculomotor Nerve Palsy

Cavernous Sinus A large channel of venous blood creating a cavity bordered by the sphenoid bone and the temporal bone of the skull

Get out of jail card when pushed for causes of Cranial nerve lesions

Oculomotor (III)Trochlea (IV)Ophthalmic nerve (V1)Maxillary nerve (V2)

Abducens (VI)

Internal carotid artery carrying sympathetic plexus

Horner’s

Tumours, thrombosis, aneurysms, infections

IV and VI Nerve

Superior Oblique - IVLateral Rectus - VI

Don’t effect pupil Don’t effect eyelid

“The patient has a convergent strabismus on the right at rest”

Failure to Abduct the eye

VI Nerve Palsy

Superior Oblique - IVLateral Rectus - VI

“Pupils are equal, no ptosis”

Abducens only job

Right convergent strabismus.

“There is diplopia maximal on right lateral gaze ” (towards the affected side)

(because you are trying to move the eye outwards with a non-functioning lateral rectus muscle)

?

Outmost image comes from the affected eye

Covering the right eye removes the outer most image

VI (Abducens) Nerve Palsy

• Only innervates Lateral Rectus so can move eye outwards

• Convergent strabismus at rest

• Diplopia towards affected side• Outermost image comes from affected

eye

VI Nerve Palsy

IV Nerve Palsy• RARE and Unlikely for finals

Trauma is most commonSuperior oblique – IN and DOWN

Therefore in a palsy eye appears higher.

IV Nerve Palsy• RARE and Unlikely for finals

Trauma is most commonSuperior oblique – IN and DOWN

Therefore in a palsy eye appears higher.

• Rare. Trauma.

• Eye higher

• Head tilt to opposite side.

IV Nerve Palsy

MONONEURITIS MULTIPLEX• Get out of jail card for nerve lesions• Simultaneous or sequential involvement of individual non-contiguous nerves

WARDS PLC

WegenersAIDS/AmyloidRheumatoidDiabetesSarcoidPolyarteritis nodosaLeprosyCancer

1. Diabetes2. Vasculitis3. Rheumatoid

IIIrd nerve palsy “What are the causes?”

Surgical:Tumour

AneurysmHaemorrhage

Medical:Diabetes

…Mononeuritis multiplex

MONONEURITIS MULTIPLEX• Get out of jail card for nerve lesions• Simultaneous or sequential involvement of individual non-contiguous nerves

WARDS PLC

WegenersAIDS/AmyloidRheumatoidDiabetesSarcoidPolyarteritis nodosaLeprosyCancer

1. Diabetes2. Vasculitis3. Rheumatoid

Foot drop….“What are the causes?”

“Common peroneal nerve lesion (L5/S1)”External compression (cast)

Trauma (head of fibula)Motor Neurone disease

Charcot Marie Tooth…Mononeuritis multiplex”

VISUAL FIELDS

Age related macular degeneration

Retinitis pigmentosa

Arcuate scotomaGlaucoma

Migraine

Bitemporal Hemianopia

• Common for finals• Easy to detect

“Represent a lesion at the optic chiasm”• Pituitary tumour

↓TSH↓T4

Bitemporal Hemianopia

• Common for finals• Easy to detect

“Represent a lesion at the optic chiasm”• Pituitary tumour

• Craniopharyngioma•Menigioma/Glioma

Pituitary tumour

Craniopharyngioma

From Hemiparesis to Homoymous Hemianopia

One of the most likely Neuro cases

Start with PRONATOR DRIFTBe patient

Ask if Right or Left Handed

Diagnosed Hemiparesis1. Stroke2. MS3. Tumour

Diagnosed HemiparesisBAMFORD Classification of Stroke

1. Hemiparesis2. Hemianopia3. Loss Higher functioning

x3 = TOTAL ANTERIOR CEREBRAL INFARCTX2 = PARTIAL ANTERIOR CEREBRAL INFARCT

Dead @ 1 Year

60%16%

1. Stroke2. MS3. Tumour

PICK UP A PEN TORCH“Im looking for an RAPD”

Hemiparesis + RAPD ………………………………….. MULTIPLE SCLEROSIS

“What are the causes RAPD?......”“Disorders of the optic nerve

Or Disorders of the Retina… I would therefore like to perform fundoscopy

Optic nerve:

Optic neuritis/atrophy – Multiple Sclerosis

Retina:Retinal detachment, retinal vein or artery occlusion, severe diabetic retinopathy

“RAPD there must be a difference in the extent of the disease between the two eyes”

SPECIAL CASESMULTIPLE SCLEROSIS

Multiple Sclerosis, Multiple Eye Signs

• RAPD – optic neuritis/atrophy• Ophthalmoplegia – any individual muscle or

combination• Nystagmus (cerebellar involvement)• Internuclear opthalmoplegia (INO)

• III VI

• VI III

Internuclear OphthalmoplegiaMedial Longitudinal Fasciculus

Medial Longitudinal Fasciculus

• III VI

• VI III

Internuclear OphthalmoplegiaMedial Longitudinal Fasciculus

Medial Longitudinal Fasciculus

Right sided INO

Bad eye fails to ADduct

Nystagmus

• III VI

• VI III

Internuclear OphthalmoplegiaMedial Longitudinal Fasciculus

Medial Longitudinal Fasciculus

Bilateral INOFailure to ADduct in both eyes with

contralateral nystagmus= MS

SPECIAL CASESMyasthenia Gravis

Unilateral ptosis1. Horners syndrome2. III nerve Palsy3. Myasthenia Gravis

Bilateral ptosis4. Myasthenia Gravis

PtosisAccentuated by upgaze

OpthalmoplegiaVariable and complex

“Intra-saccadic fatigue”

Pupils not involved

15% pure ocular Myasthenia Gravis (more likely to be seronegative)85% generalized Myasthenia Gravis

Cerebellar eye signs1 - HORIZONTAL NYSTAGMUS

FAST (saccade)Towards side of lesion

2 - BROKEN PERSUIT

3 - ABNORMAL SACCADES