Cranial Nerves PULSE: Preparation for Finals - PowerPoint Presentation

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Cranial Nerves

PULSE: Preparation for FinalsTutor name

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TuBS attendance

https://tutorialbooking.com/

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Session overview

Common cranial nerve conditions for the OSCE

How to present your findingsSummary of clinical signsCase presentations and viva questions

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What is the purpose of an OSCE?

“This station tests a student’s ability to perform an appropriate focussed

physical examination, demonstrating consideration for the patient, and to report back succinctly describing the relevant findings. It also tests a student’s clinical judgement i.e. the ability to decide the differential diagnosis, choose investigations and formulate a management plan.”

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Common cranial nerve conditions in the OSCE

It is highly unlikely you will be asked to examine ALL cranial nerves

OphthalmoplegiaField defectsFacial nerve palsy

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Presenting your findings

What

were you asked to do?What were your key positive findings?What were the important negative

findings?

What does this

mean

?

How would you

complete your examination

, and what

investigations

would you do?

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Example case presentation

I was

asked to examine the cranial nerves of this elderly gentlemanOn examination I found that he had a failure of lateral gaze in the left eyeAll other eye movements

were intact, visual acuity was normal, and there were

no visual field defects

No abnormalities

in the other cranial nerves were detected

This would be consistent with a diagnosis of a 6th nerve palsy

To

complete my examination

I would like to perform

fundoscopy

and do a full neurological examination of the limbs – FURTHER TESTS

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Completing your examination

Complete cranial nerves examination

Formal tests1: scents2: Snellen and Ischiara charts

3, 4, 6:

fundoscopy

, corneal reflex

7: jaw jerk

9: gag reflex

Perform

fundoscopy

Full neurological examination of the limbs

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Investigations

Bloods; FBC, U&E, LFTs,

glucose, B12/folateImaging; CXR (paraneoplastic/

Horners

), CT, MRI (posterior lesions, cord)

LP; cells,

oligoclonal

bands,

xanthochromia

Other; nerve conduction studies

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Clinical signs

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Oculomotor

nerve palsy CN III

Down and out

Ptosis

Fixed dilated pupil

Causes

-

vasculitic

(DM, HTN)

- aneurysm (PCAA)

Medical

vs

surgical

Medical: DM: pupil sparing

Surgical: fixed, dilated pupil

Parasympathetic fibres run along the periphery and are the first to be affected by compression

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Why is the pupil spared in diabetic palsies?

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Trochlear Cranial Nerve Palsy CN IV

Superior oblique

Head tilt

Vertical diplopia

Causes

-

vasculopathic

- tumour

-

congenital

- trauma

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Abducens

Palsy: CN VI

Unopposed action of medial rectus

Causes

Vasculopathic

(DM, HTN)

Tumour

Intracranial pressure: false localising sign

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Cranial Nerve Cases

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Case 1

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Examination of CN I-III

WINDECSTAND BACK: observe +closely at eyes

CN I CN IICN III

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Case 1 – CN I - III

Normal smell

Normal fieldsAlso impaired looking to far left – left eye essentially fixed, bulging from socket

Pupils non reactive to light

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Case 1 – CN V onwards

Sensation – decreased in upper and mid face, normal in beard region

Facial movements otherwise normalTongue movements normal and symmetricalHearing intact. Renne

+

ve

; Weber NAD

Normal cough and speech

No neck wasting or weakness

Please present your findings.

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Case 2

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Case 2 - eyes

PERLA

Eye movements normal (?small amount of nystagmus)Normal visual fieldsSensation reduced on right throughout

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Case 2 – CN V onwards

Reduced facial movements on right, including right forehead

Partially deaf on right side – Rinne’s – air louder, Weber’s – left louder

Normal cough and voice

Tongue movements normal

No neck muscle wasting, no weakness

Bonus points – on walking, he falls to the right

Bonus

bonus

– past pointing

Please present your findings.

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Case 3

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Case 3

Please present your findings.

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What is Horner’s syndrome?

Horner’s Syndrome

= collection of signs: unilateral pupillary constriction (miosis),

ptosis and

anhydrosis

(i.e. loss of sympathetic pathway on that side).

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What are the causes of Horner’s syndrome?

Hemisphere and brainstem

Massive cerebral infarctionPontine gliomaVascular disease (esp. lateral medullary syndrome – infarction of lateral medulla, due to occlusion of vertebral artery, posterior inferior cerebellar artery, superior, middle or inferior medullary arteries)

‘Coning’ of the temporal lobe

Cervical cord

Syringomyelia

Cord tumours

T1 root

Apical bronchial neoplasm (usually SCC)

Apical TB

Cervical rib

Brachial plexus trauma or tumour

Sympathetic chain in neck

Post thyroid/laryngeal surgery

Malignancy, e.g. thyroid; neoplastic infiltration

Cervical

sympathectomy

Carotid artery

Occlusion/dissection

Pericarotid

tumours (Raeder’s syndrome)

Cluster headache

Miscellaneous

Congenital

Migrainous

neuralgia (usually transient)

Isolated and unknown cause

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Cranial nerve summary

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Groups of nerve palsies

III and IV – midbrain nuclei

V, VI, VII, VIII – pons nucleiIX, X, XI, XII – medulla nucleiUnilateral III, IV, VI,

Va

– cavernous sinus lesion; superior orbital fissure lesion (

Tolosa

-Hunt syndrome)

Unilateral V, (VI), VII, VIII, (IX) –

cerebellopontine

angle lesion (usually tumour)

Unilateral IX, X, XI – jugular foramen lesion

Eye and facial muscles, worse on exertion – myasthenia gravis

UMN IX, X, XII –

pseudobulbar

palsy

LMN IX, X, XII – bulbar palsy

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Summary

Common cranial nerve conditions for the OSCE

How to present your findingsSummary of clinical signsCase presentations and viva questions

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Please complete

TuBS feedback

Tutor detailsFor more information on Examining for Finals sessions:examiningforfinals@gmail.com

www.sefce.net/pulse

Resource Updated 2017: Dr A Swan

With thanks to previous contributors:

Dr Emma Claire Phillips (FY2)

Dr Kristina Lee (FY2)