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Examination (Examine patient‟s eyes, CNs) Complete the eye examination Rule out MG, thyroid

Rule out Cavernous Sinus syndrome, Superior orbital fissure syndrome Proceed to check cranial nerves

V, VII and VIII for CPA tumor

XI, X, XI, XII for any base of skull lesions Examine upper limbs

Hemiplegia (long tract signs suggesting brainstem)

Cerebellar signs (CPA lesion, Miller Fisher usually truncal and gait) Reflexes for areflexia (Miller Fisher)

Examine the neck for LNs and mastoid for tenderness (Gradenigo‟s syndrome) Request

Fundoscopy (papilloedema from raised ICP, optic atrophy for MS) Field testing (bitemporal hemianopia)

Acuity (reduced in orbital lesions)

Corneal testing for reduced sensation form V1 involvement BP

Urine dipstick

Temperature chart for fever(meningitis) Ask for retrobulbar pain

Presentation

Sir, this patient has an isolated right sided VI nerve palsy as evidenced by Convergent strabismus at primary gaze

Failure of abduction of the right eye

With diplopia where the image is side by side and furthest apart on rightward gaze, with disappearance of the outer image on covering the right eye. This suggests a right lateral rectus muscle weakness and hence a right VI nerve palsy.

There is no evidence of a III or IV or V1 palsy which may suggest cavernous sinus or superior orbital syndrome.

There is also no involvement of the VII or VIII nerve palsy and no cerebellar signs to suggest A CPA lesion There are no associated CN lesions of IX to XII and no enlarged Cx LNs.

There is no fatiguibilty to suggest MG and no thyroid eye signs.

There are no enlarged LNs or tender mastoid. There is also no hemiparesis, no cerebellar signs and reflexes are present.

I would like to complete my examination by:

Fundoscopy (papilloedema from raised ICP, optic atrophy for MS, DM or hypt changes) Field testing (bitemporal hemianopia)

Acuity (reduced in orbital lesions)

Corneal testing for reduced sensation form V1 involvement BP

Urine dipstick

Temperature chart for fever(meningitis) Ask for retrobular pain

In summary, this patient has an isolated right sided VI nerve palsy. The aetiology includes….

Questions

What is the course of the VI nerve?

Nucleus of CN VI located in the pons, sending motor neurons supplying the lateral rectus muscle of the ipsilateral eye;

also internuclear neurons that project (via MLF) to medial rectus subdivision of contralateral oculomotor (CN III) nucleus (ie lesion of nucleus causes ipsilateral horizontal gaze palsy)

nerve fascicles exit the pons anteriorly and course through subarachnoid space where it runs a vertical (upward) course, along ventral surface of pons (confined by adjacent AICA)

pierces dura overlying clivus, entering into Dorello's canal, contacting tip of petrous pyramid (part of temporal bone; adjacent to mastoid air cells)

enters the cavernous sinus after passing through the petroclinoid (Gruber's) ligament

runs in body of sinus (rather than lateral wall where CN III, IV, V located) along foramen lacerum (near internal carotid artery) enters orbit via superior orbital fissure and shortly thereafter pierces lateral rectus muscle

78 What are the causes of a unilateral VI nerve palsy?

Brainstem (Pons)– infarct, haemorrhage, abscess, demyelinating (look for VI and VII palsies due to close proximity) Aneurysm (ectatic basilar artery)

Meningitis

Infective – TB, Fungal, HIV, Syphilis, Lyme

Mitotic – leptomeningeal carcinaomatosis, secondaries(NPC), lymphoma, radiotherapy Sarcoidosis

Trauma CPA lesions

Petrous temporal bone (Gradenigo‟s syndrome) Cavernous sinus syndrome

Superior orbital syndrome Miller Fisher syndrome Mononeuritis multiplex DM, hypertension MG

Raised ICP

NB: - most common aetiology of isolated abducens lesion is post-viral in children and ischemia / infarction (eg diabetic) in adults What are the causes of bilateral VI nerve palsy?

Leptomeningeal causes (see above) Miller Fisher syndrome

Mononeuritis multiplex MG

Raised ICP

Wernicke‟s encephalopathy (Ophthalmoplegia, confusion and ataxia a/w Korsakoff‟s psychosis from thiamine deficiency) What are the syndromes associated with VI nerve palsy?

Central

Raymond‟s syndrome – ipsilateral VI with contralateral hemiparesis

Millard-Gubler syndrome – Ipsilateral VI and VII with contralateral hemiparesis Peripheral

Gradenigo syndrome – inflammation of the tip of the petrous bone from mastoiditis; VI and V(gasserian ganglion therefore ipsilateral pain) and VII

CPA

Cavernous sinus Superior orbital Congenital

Mobius syndrome (VI with facial diplegia)

Duane‟s syndrome (Congenital absence of VI nuclei with III nuclei innervating the lateral recti; orbit retraction on adduction and protrusion on abducting

How do you evaluate diplopia?

Evaluation of diplopia follows 3 rules

o The double vision is maximal in the direction of gaze in the affected muscle o The false image is the outer image

o The false image arises form the affected eye What is Cavernous sinus syndrome?

Lesion in the cavernous sinus leading to

Ophthalmoplegia, V1, Horner‟s, proptosis, chemosis and pain

Causes include carotid aneurysm, carotid-cavernous fistula, tumour and thrombosis, Tolosa Hunt syndrome What is superior orbital fissure syndrome?

Lesions occurring at the superior orbital fissure leading to

Ophthalmoplegia, V1, Horner‟s, proptosis, chemosis, pain and Optic Nerve

Causes includes meningiomas, hemangiomas and thyroid eye disease, Tolosa Hunt syndrome What is Miller Fisher syndrome?

Triad of ophthalmoplegia, ataxia and areflexia Cs by present of anti GQ1B antibodies Variant of GBS

What are the causes of mononeuritis multiplex?

Endocrine – DM, hypt

AI – Churg Strauss, Wegener‟s, PAN, Sjogren‟s, RA, SLE Infective – Lyme, leprosy

Infiltrative – Amyloid, sarcoid

How would you investigate?

Blood tests

fasting glucose, ESR, ANA, VDRL Imaging

CT brain or MRI brain

Vascular imaging if proptosis / chemosis looking for dural carotid-cavernous fistula or cavernous sinus thrombosis Examine CSF (also if systemic illness, immunocompr, bilateral, other CN deficits)

8-30% will remain cryptogenic after work-up How would you manage?

Education on Px if ischaemic (see below) and Ix and avoid driving, climbing high places and operating heavy machinery Treat underlying cause

Example control DM and BP Symptomatic treatment

Patch Prism

If chronic, chemodenervation with botox or strabismus surgery What is the prognosis?

most either spontaneously improve or have underlying lesion found

ischemic palsies almost always recover completely in 2-4 months while some recovery seen in half of traumatic cases (but take over one year)

if no recovery over 3-6 months then suspect underlying lesion such as tumour few may have chronic isolated abducens palsy of unknown cause

follow regularly looking for emergency of new localizing signs and ensure adequate neuroimaging and ENT evaluation

80 35. VII Nerve Palsy

Examination

Upon noticing facial asymmetry, proceed to tests VII nerve functions

Look up (frontalis) and attempt to push the folds down, close your eyes (orbicularis oculi) and attempt to force them open, and frown (corrugator superficialis)

Look for exposure keratitis, tarsorraphy

Nasolabial fold, show your teeth and and blow against closed lips Look for drooling of saliva

Determine UMN or LMN, unilateral or bilateral UMN unilateral

Examine UL and look for hemiparesis on the same side of the facial weakness Check for xanthelesma, DM signs and BP

LMN unilateral Examine other CN

VI nerve and contralateral weakness in brainstem lesions CPA lesion (V, VI, VII and VIII with cerebellar)

Other CN nerves involvement non-conforming type Basal meningitis lesions

Mononeuritis multiplex, MG

Therefore proceed to examine the neck Look at the Palate for vesicles

Examine the parotids and for surgical scars Mastoid tenderness

Examine the neck for cervical LNs Upper limbs

Contralateral hemiparesis Ipsilateral cerebellar Ask to examine

Otoscopy for vesicles in EC and otitis media

For hyperacusis (sensitive to high-pitched or loud sounds) For loss of taste in the anterior two-thirds of the tongue Urine dipstick for glucose and BP

Upon noticing facial diplegia, proceed with Rule out MG (Bilateral ptosis)

Rule out Dystrophia myotonica or fascio-scapular-humeral dystrophy Bilateral LMN VII

Test for frontalis, corrugator and orbicularis oculi Ask patient to show teeth and blow against closed lips Look for V, VI, VIII

Examine parotids (Sarcoidosis, amyloidosis) Examine tongue (scrotal tongue for MR syndrome)

Examine ULs for GBS, MND, leprosy, Lyme‟s (radiculopathy) & bilat cerebellar signs if suggestive of bilateral CPA tumors Think of rare: Melkersson-Rosenthal syndrome, Mobius syndrome

Presentation

Sir, this patient has got a right sided lower motor neurone facial nerve palsy as evidenced by:

Paralysis of both the upper and lower facial muscles on the right

Loss of wrinkling of the right side of the forehead, inability to fully close his right eye shut with Bell‟s phenemenon Associated with loss of the right nasolabial fold and drooping of the right angle of the mouth

There are no cxs of exposure keratitis, no drooling of saliva. I also did not notice any evidence of a right sided tarsorraphy There is no associated VI nerve palsy to suggest a brainstem lesion.

There are also no features of Cerebellopontine angle lesion with no involvement of the V, VI, VIII or cerebellar signs on the right.

I did not find any evidence of a parotid swelling or a surgical scar and there are no vesicles on the palate. There was no right sided facial oedema or plication of the tongue to suggest the rare syndrome of MR syndrome.

There is no mastoid tenderness and no enlarged cervical LNs. I did not detect any contralateral hemiparesis or cerebellar signs.

I would like to complete my examination by Otoscopy for vesicles in EC and otitis media

Ask about hyperacusis (sensitive to high-pitched or loud sounds) Ask for loss of taste in the anterior two-thirds of the tongue Urine dipstick for glucose and BP (mononeuritis multiplex)

The most likely cause for this patient would be a right sided Bell‟s palsy.

Questions

What is the course of the facial nerve?

VII nerve nucleus lies in the pons in close proximity with VI nerve nuclei VII leave the pons with VIII via the cerebellopontine angle

It enters the facial canal and enlarges to become the geniculate ganglion

A branch is given off to the stapedius muscle and the greater superficial petrosal branch goes to the lacrimal glands

The chorda tympani which supplies taste sensation to the anterior two thirds of the tongue joins the VII nerve in the facial canal VII nerve exits the skull via the stylomastoid foramen, through the parotids with the following branches

Temporalis Zygomatic Buccal Mandibular Cervical

What are the causes of a unilateral LMN VII nerve palsy?

Brainstem (Infarct/haemorrhage, MS, abscess and tumour, syringobulbia) Base of skull lesions (infective, tumour, infiltrative)

CPA lesions (acoustic neuroma, meningioma, neurofibroma) Petrous temporal bone (Bell‟s palsy, Ramsay Hunt, OM) Parotid (tumour, sarcoidosis, surgery)

Mononeuritis multiplex NB: Most common is Bell‟s palsy

What are the causes of bilateral LMN VII nerve palsies?

After ruling out MG and myopathies Bilateral CPA tumor as in NF type 2 Bilateral Bell‟s palsy

Bilateral Parotid enlargement (Sarcoidosis – Uvoeoparotid fever or Heerfordt‟s fever) GBS, MND and leprosy, Lyme disease

Rare: Rosenthal Melkersson syndrome (triad of VII palsy with facial edema and plication of the tongue, Mobius syndrome (congenital facial diplegia, oculoparalysis from III and VI and infantile nuclear hypoplasia)

What is Bell‟s phenemenon?

It refers to the upward movement of the right eyeball with incomplete closure of the right eyelid in an attempt to close the right eye.

Why are the muscles of the upper face spared in a upper motor neurone lesion?

The upper facial muscles are preserved in an UMN lesion as there are bilateral cortical representations of these muscles.

What is Bell‟s palsy?

An idiopathic facial paralysis, believed to be due to viral-mediated cranial neuritis from HSV

Typically presents with abrupt onset of weakness with worsening the following day, associated with facial or retroauricular pain, hyperacusis and excessive tearing

What is Ramsay Hunt syndrome?

Herpes zoster infection of the geniculate ganglion

Presents with vertigo, hearing loss, facial weakness, pain in the ear with vesicles seen on the external auditory meatus and palate

What is facial synkinesis?

Attempt to move one group of facial muscles results in movement of another group Occurs as a result of anomalous regeneration of the facial nerve

Egs if nerve fibres which innervate the facial muscles later innervate the lacrmial glands, then patient shed tears on mastication (crocodile tears)

How would you investigate?

Targeted Ix according to history and physical examination Blood Ix eg Lyme‟s disease

Imaging

How would you manage (Bell‟s palsy)?

Educate

Lubricating eye drops, eye patch, physiotherapy

PO Pred 1mg/kg/d for 7-10 days and PO acyclovir 400mg 5X/d for 7 days (within first 72hrs)

Regular follow up to look for resolution and exclude new developing signs suggestive of other conditions Surgical (tarsorraphy) for chronic non-resolving cases

82 How would you educate or counsel patient with Bell‟s palsy?

Common condition Course

Improvement onset: 10 days to 2 months Plateau: 6 weeks to 9 months

Residual signs Synkinesis

Frequency: ~50%; May be reduced by corticosteroid treatment May be treated with botulinum

Probably due to anomalous regeneration of nerve Crocodile tears: 6%

Face weakness: 30%

Contracture: 20%

Blepharospasm: May occur years after paralysis Prognosis better

Incomplete paralysis Early improvement Slow progression Younger age Normal salivary flow Normal taste

Electrodiagnostic tests normal Nerve excitability Electrogustometry

36. Myasthenia Gravis

In document El centro histórico de Orihuela : análisis de lesiones en fachadas (página 103-108)