cranial nerve injuries

CRANIAL NERVE INJURIES:

Dr. Karishma . Jagad M.P.T ( Neuro ) CRANIAL NERVE INJURIES

I. OLFACTORY NERVE:

I. OLFACTORY NERVE

RELEVANT ANATOMY:

RELEVANT ANATOMY Olfactory bulb Cribriform plate Nasal cavity

testing:

testing Test both perception and identification of smell Use aromatic non irritant material One nostril is closed while the pt sniffs with the other

lesion:

lesion Impairement or loss of smell – anosmia May be unilateral / bilateral May be temperory / permanent Ability to sense pain form nasal epithelium intact

causes:

causes Temperory impairement URTI (inflammation of nasal mucosa) Temperory / permanent impairement Head injury

causes:

causes Viral infection Drugs : penicillamine Endocrine disease ( addison’s disease & thyrotoxicosis0 Tumours (olfactory groove meningioma /frontal lobe tumours ) Aneurysm of circle of willis (ant communicating / opthalmic artery) Raised intracranial pressure

causes:

causes Foster Kennedy syndrome Ipsilateral anosmia Ipsilateral optic atrophy Contralateral papilloedema

II. OPTIC NERVE:

II. OPTIC NERVE

testing:

testing

testing:

testing

testing:

testing

testing:

testing Optic fundus Note the clarity of the disc edge Look for haemmorhages or white patches of exudate Note width of blood vessel Look for arteriovenous nipping

testing:

testing Pupils Size Shape Equality Reaction to light Reaction to accomodation

Light reflex:

Light reflex

Optic nerve lesion:

Optic nerve lesion Affected eye When light is shone in the normal eye, it and contralateral pupil will constrict A lesion of optic nerve will abolish pupillary response to light on the same side as well as in the contralateral eye

Optic nerve lesion:

Optic nerve lesion

Optic nerve lesion:

Optic nerve lesion Causes : Hereditory optic neuropathy Glaucoma Ischemia

Optic nerve lesion:

Optic nerve lesion Optic neuritis (younger than 50 years) Inflammation Toxicity Trauma Compression from tumours or aneurysm Optic nerve hypoplasia

III. Occulomotor nerve:

III. Occulomotor nerve

Relevant anatomy:

Relevant anatomy

lesion:

lesion Lesion in Lt occulomotor nerve causes Lt eyeball to deviate downwards and somewhat outwards 70% fibers of levator palpabrae is supplied by occulomotor nerve which causes ptosis in Lt occulomotor nerve lesion

lesion:

lesion Light shone in the affected eye – contralateral pupil constrict Light shone in normal eye – pupil on that side constricts CONSENSUAL RESPONSE

lesion:

lesion Causes Direct trauma Demyelinating disease (e.g., multiple sclerosis) Raised ICP causing uncal herniation Due to SOL Spontaneus subarachnoid haemmorhage Microvascular disesase (diabetes)

IV. Trochlear nerve:

IV. Trochlear nerve

s/s of trochlear nerve lesion:

s/s of trochlear nerve lesion A = involved (right) eye is elevated on forward gaze B = extent of elevation is increased with adduction C = extent of elevation is decreased with abduction D = Elevation is increased with head tilting to the affected side E = Elevation is decreased with head tilting in the opposite direction

s/s of trochlear nerve lesion:

s/s of trochlear nerve lesion Diplopia when looking downwards (vertical diplopia) Head may tilt to the side opposite to the weak superior oblique to minimize diplopia

lesion:

lesion Causes: Infarction Haemmorhage AV malformation Tumours Demyelination Generalized increase in intracranial pressure Congenital defect

VI. Abducent nerve:

VI. Abducent nerve

lesion:

lesion On looking to the paralysed side there is failure of abduction of the affected eye Horizontal diplopia Check the diplopia is true by noting its disappearance on converging eye Determine the direction of maximum displacement Determine the eye responsible for outermost imge

lesion:

lesion Lesion of dorsal pons – ipsilateral facial palsy with lateral gaze palsy Lesion of ventra pons – contralateral hemiparesis with lateral gaze palsy

lesion:

lesion Damage to abducent nucleus produces horizontal gaze palsy Abducent nucleus contain 2 types of cells neurons control lateral rectus muscles of same side Interneurons cross to the opposite side to connect with occulomotor nucleus

lesion:

lesion Causes : Tumours aneurysm or fractures – directly compresses/stretches the nerve Strokes, demyelination, infection Diabetic neuropathy Wernicke-Korsakoff syndrome Indirect traction due to brain tumor, hydrocephalus, hemorrhage, edema

VII. Facial nerve:

VII. Facial nerve

test:

test O/O : Eye closure Asymmetrical elevation of one corner of mouth Flattening of nasolabial fold

test:

test O/E: Wrinkle forhead (frontalis) Close eyes (o. occuli) Puff cheeks (buccinator) Show teeth (o.oris) Taste : using sugar, tartaric acid or sodium chloride

Lesion :

Lesion Unilateral involvement of lower face, with near normal eye closure  CONTRALATERAL SUPRANUCLEAR LESION Unilateral involvement of upper and lower face with defective eye closure  IPSILATERAL NUCLEAR/INFRANUCLEAR LESION Bilateral involvement of upper and lower face  BIL NUCLEAR, BIL INFRANUCLEAR / MUSCLE DISEASE

Slide 38:

PONS VI nerve palsy Contralateral limb weakness CAUSES: Vascular Demyelination Tumour Encephalitis Syringobulbia MND CEREBELLOPONTINE ANGLE V and VIII nerve palsies Loss of taste, salivation, and lacrimation Hyperacausis CAUSES Acoustic tumours Epidermoid tumours FACIAL CANAL Loss of taste and salivation Hyperacousis (if proximal to nerve to nerve to stapedius ) Lacrimation retained CAUSES # skull base Spread of middle ear infection Herpes zoster PERIPHERAL NERVE Lacrimation , taste and salivation retained Weakness may be localised to specific muscle group CAUSES Parotid gland lesion Parotid operation Facial trauma

VIII. VESTIBULOCOCHLEAR NERVE:

VIII. VESTIBULOCOCHLEAR NERVE

TEST OF COCHLEAR PART:

TEST OF COCHLEAR PART

Slide 41:

WEBER’S TEST RINNE’S TEST

DEAFNESS :

DEAFNESS Three types of hearing loss: Conductive deafness : failure of sound conduction to the cochlea Sensorineural deafness : failure of action potential production or transmission due to disease of cochlea, cochlear nerve or cochlear central connection Pure word deafness : bilateral / dominant post temporal lobe lesion prodices failure to understand spoken language despite preserved hearing

tinnitus:

tinnitus Tinnitus may be: Continuous / intermitent Unlateral / bilateral High pitch / low pitch When hearing loss is accompanied by tinnitus: Conductive deafness – low pitch tinnitus Sensorineural deafness – high pitch tinnitus Pulsing tinnitus – vascular cause

Vertigo :

Vertigo Illusion of rotatory movt due to disturbed orientation of the body in space Cause: Disease of labyrinth Vestibular nerve Central connections of labyrinth and vestibular nerve

Ix. GLOSSOPHARYNGEAL NERVE:

Ix. GLOSSOPHARYNGEAL NERVE

Slide 46:

Motor fibers to stylopharyngeus parasympathetic fiberes to parotid gland Sensory fibers innervate post third of tongue, pharynx, eutachian tube and carotid sinus OTIC GANGLION

TEST:

TEST GAG REFLEX Compare the sensitivity on each side (afferent route – IX nerve) Observe the symmetry of palatal contraction (efferent route – X nerve) Absent gag reflex = loss of sensation and/or motor power Taste sensation in post third of tongue

Glossopahryngeal neuralgia:

Glossopahryngeal neuralgia Short sharp lancinating attacks of pain Affects post part of pharrynx or tonsillar area Pain radiates towards ear and triggered by swallowing Reflex bradycardia and syncope may occur

Glossopahryngeal neuralgia:

Glossopahryngeal neuralgia Treatment: Carbamazepine provides good relief Microvascular decompression or section of IX nerve roots ISOLATED GLOSSOPAHRYNGEAR PALSY DOES NOT OCCUR

X. VAGUS NERVE :

X. VAGUS NERVE

Function :

Function Motor parasympathetic fibers to all organs except suprarenal gland Supplies skeletol muscles namely: Cricothyroid muscle Levator veli palatini muscle Salpingopharyngeus muscle Palatoglossus muscle Palatopharyngeus muscle Superior, middle and inferior pharyngeal constrictors Muscles of the larynx (speech).

Test :

Test Gag reflex: Uvula swings due to unopposed muscle action on one side Palatal weakness

Lesion :

Lesion Palatal weakness: Unilateral – minimal symptom Bilateral – nasal regurgitation, nasal quality of speech Pharyngeal weakness: Unilateral – pharyngeal wall droops on the affected side Bilateral – marked dysphagia

Lesion :

Lesion Vagus nerve lesion above the origin of reccurent and superior laryngeal nerves: Unilateral – mild dysphagia, hoarseness of voice and reduced vocal strength Bilateral damage – weak cough

XI. Cranial accessory nerve:

XI. Cranial accessory nerve

Lesion :

Lesion Supplies sternocleidomastoid and trapesius Unilateral lesion results in weakness of ipsilateral trapezius and trapezius

XII. Hypoglossal nerve:

XII. Hypoglossal nerve

Test :

Test Inspect the tongue: Look for – evidence of atrophy Fibrilation Ask the pt to protrude the tongue

Relevant anatomy:

Relevant anatomy Supplies intrinsic muscles of tongue Each nucleus is bilaterally innervated Unilateral supranuclear palsy will not produce symptoms Bilateral suupranuclear lesion – thin spastic tongue which cannot be protruded

Lesion :

Lesion Infranuclear lesion Atrophy and deviation of tongue to the weak side

CAUSES OF LOWER CRANIAL NERVE PALSIES:

CAUSES OF LOWER CRANIAL NERVE PALSIES Skull base/intracranial Basal skull tumours – meningioma, neurofibroma, metastasis, epidermoid etc Bone lesion – osteomyelitis Basal menigitis Carcinomatous meningitis

CAUSES OF LOWER CRANIAL NERVE PALSIES:

CAUSES OF LOWER CRANIAL NERVE PALSIES Brain stem Infarction Demyelination MND Syringobulbia Poliomyelitis Intrinsic tumour e.g., astrocytoma

CAUSES OF LOWER CRANIAL NERVE PALSIES:

CAUSES OF LOWER CRANIAL NERVE PALSIES Neck Penetrating injury Neck operation Tumours Systemic causes Diabetes Meningovascular syphillis Sarcoidosis SLE

LOWER CRANIAL NERVE syndromes :

LOWER CRANIAL NERVE syndromes Jugular foramen syndrome Lesion involving IX,X and XIth nerves Collet sicard syndrome Extracranial lesion involving IX, X, XI and XII nerves

LOWER CRANIAL NERVE syndromes :

LOWER CRANIAL NERVE syndromes Villaret’s syndrome Lesion of retropharyngeal space Involves IX, X, XI, XII nerves and cervical sympathetics Polyneuritis cranialis Multiple cranial nerve palsies of unknown etiology Remit spontaneusly Occasionaly occur with GBS

Slide 66:

THANK YOU