2. facial,glossopharyngeal,cervical plexus

GOOD

MORNING

Facial Nerve ,

Glossopharyngeal

Nerve & Cervical

Plexus of Nerves

IntroductionFunctional componentsNucleiCourse Branches & DistributionGanglia AssociatedBlood supplyAge changesVariation in branching patternsNerve lesions : supranuclear infranuclearCauses of facial paralysisBells palsyManagement of facial palsyNerve disorders in childrenTesting of facial nerve Applied Anatomy

CONTENTS :FACIAL NERVE

7th cranial nerve

Mixed nerve

motor components

sensory components

2nd arch

INTRODUCTION

SPECIAL VISCERAL EFFERENT (BRANCHIAL)

muscle response for

1, facial expression

2. Elevation of hyoid bone

Functional components

Special visceral afferent

These fibers carry taste sensation from anterior 2/3 rd of tongue& palate

GENERAL VISCERAL EFFERENT (parasympathetic)

Secretomotor to the

•Submandibular gland

•sublingual gland ,

• lacrimal gland ,

• glands of the nose,the palate,and the pharynx

GENERAL SOMATIC EFFERENT

General sensation

from the skin of the concha of the auricle &from a small area behind the ear.

Nuclei

Motor Nucleus

Superior Salivatory nucleus

Upper part of nucleus of tractus solitarius

Upper part of spinal nu of trigeminal nerve

Cranial nerve nuclei

Course of a facial nerve

INTRA CRANIAL

INTRA TEMPORAL

EXTRA CRANIAL

Intra cranial course:

Two roots…..lower border of pons..

motor root medial to sensory root

stylomasoid divide…

Sensory root & motor root passes forwards and laterally leave the …….

Intra Temporal (within Facial Canal )

Extracranial part

Submandibular gland

BRANCHES

Within facial canal

1.Greater petrosal nerve

2.Nerve to stapedius

3.Chorda tympani

At its exits from the stylomastoid foramen

1.Posterior auricular

2.Digastric

3.stylohyoid

Terminal branches

1.Temporal

2.Zygomatic

3.Buccal

4.Mandibular

5.cervical

Greater Petrosal Nerve

Nerve to Stapedius

CHORDA TYMPANI

At its exits from the stylomastoid foramen

TERMINAL BRANCHES

GANGLIA ASSOCIATED WITH THE FACIAL NERVE

location…..

Sensory and parasympathetic -nervus intermedius.

Motor fibers are carried via the facial nerve proper.

greater petrosal nerve, which carries sensory fibers as well as preganglionic parasympathetic fibers

Geniculate ganglion

Pterygopalatine Ganglion

BRANCHES OF PTERYGOPALATINE GANGLION

orbital

palatine

Nasal1.Lateral post.sup nasal nerve

2.Medial post.sup nasal nerve

3.nasopalatine

pharyngeal

SUBMANDIBULAR GANGLION it lies on ….

topograpically…

functionally…

Motor

Superior salivatory nucleus

Nervus intermedius

chorda tympani

Lingual nerve

Ganglion

GLAND

Sympathetic root

Plexus around the facial artery

supply vasomotor fibers to submandibular & sublingual gland

Sensory root

Lingual nerve

Facial nerve – Blood SupplyIntracranial/Meatal: labyrinthine branches from ant .

inf cerebellar artery

Perigeniculate: superficial petrosal branch of middle meningeal artery

Tympanic/Mastoid: stylomastoid branch of posterior auricular artery

Branching Patterns

13%

20%

28%

6%

9%

24%

AGE CHANGES

CLINICAL CONSIDERATION & TESTING OF FACIAL NERVE

CLINICO ANATOMICAL CONSIDERATION by using knowledge of the anatomy of the facial nerve the location of a lesion can be determined by presence or absence of certain deficits

Testing of facial nerve

Topographic testing

1.schirmer’s test

2.Stapedial reflex

3.Taste testing

4.Salivary flow rate & salivary ph

Electro-physiological testing

Nerve excitability testing( NET)

Maximum stimulation test(MST)

Electroneuronography| (ENOG)

Electromyography (EMG)

Topographic testingschirmer’s test

Stapedial reflex

Evaluates…

Impedance audiometry

Taste testing

Electrogustometer

Salivary Flow rate & salivary pH

Normal values:

Saliva ph - 6.7-7.4

Volume – 600-1000 ml/day

Resting flow rate – 0.2-0.4 ml/m

Stimulated flow rate - 2-5 ml/m

Facial paralysis

Upper motor neuron palsy

Lesion above the level of pons

Lower motor neuron palsy

Lesion is in the pons or in the pathway from pons to its exit

UMN LMN

Paralysis of lower ½ of face on C/L side

Total facial paralysis on same side

Emotional movements (e.g. Laughing) are intact.

Emotional movements are lost

Associated hemiplegia No hemiplegia

Hypertonia (spastic). Hypotonia (flaccid).

No fasiculation. Fasiculations are present.

No muscle atrophy. Muscle atrophy occurs later.

Facial nerve disorders

TRAUMA: birth trauma, temporal bone fractures,

skull base fractures, facial injuries middle ear injuries, surgical trauma.

Nervous system disease: Opercular syndrome, Millard-Gubler syndrome.

Infection: of the ear or face,

Herpes zoster of the facial nerve (Ramsey-Hunt syndrome).

Factors causing Facial Nerve Disorders

Metabolic: diabetes mellitus Tumors: acoustic neuroma schwannoma, cholesteatoma, malignant parotid tumors, glomus tumors. Toxins: alcoholism carbon monoxide poisoning.

Bell's palsy: Also called idiopathic facial nerve paralysis

Facial nerve disorders in children

Bell’s palsy

Sudden occurrence of a flaccid facial paralysis in a apparently healthy individual

(1774-1882)

Bell’s phenomenon:

DRUG DOSE PREDNISOLONE Adults: 60 mg daily for five

days, then 40 mg daily for five days

Children: 2 mg per kg daily for seven to 10 days

ACYCLOVIR (ZOVIRAX) Adults: 400 mg five times daily for seven days

Children older than two years: 80 mg per kg daily divided every six hours for five days

Treatment plan

recent research shown that no added benefit of acylovir compared to prednisolone alone for treatment of bell’s palsy

Eye protection Lubricating eye drops, such as artificial tears eye ointments or gels eye patches Facial massage and exercises

Moist heat

Surgical decompression & cosmetic reconstructive surgery

To preventExposure keratitis

About 80% of patients recover spontaneously within 12 weeks

Syndromes associated with Bell’s Palsy

JamesRamsayHuntSyndrome

MelkerssonRosenthalSyndrome

Moebius Syndrome

Gullian barre syndrome

James Ramsay Hunt Syndrome

Melkersson Rosenthal SyndromeFacial palsy

cheilitis

Fissured tongue

Moebius Syndrome

Facial diplegia

Bilateral paralysis of ocular muscles.

Glossopharyngeal nerve

Contents:IntroductionNucleiFunctional componentsCourse Branches & DistributionGanglia AssociatedApplied Anatomy

INTRODUCTIONNinth cranial nerve

3rd arch

Mixed nerve

o Branchio Motor…

o Preganglionic secretomotor…

o general somatic Sensation….

oSpecial visceral (taste) sensation ….

o general visceral sensory…baro n chemo

nuclei

COURSE & RELATIONS

Intra cranial

Attached to lateral side of upper part of the medulla between olivary body & the inferior cerebellar peduncle

It leaves the cranial cavity ….

Extra Cranial Course

Branches

communication

distribution

TympanicCarotid

PharyngealMuscularTonsillarlingual

OTIC GANGLION

Located in…

Topographically…..

Functionally ……

Glossopharyngeal Nerve Testing 1.Taste sensation

2, gag reflex

Afferent – 9th

Efferent – 10th

On tickling the posterior wall of the pharynx ,there is reflex contraction of the throat muscles.

No such contraction occurs when ninth nerve is paralysed

Transient or sustained hypertension : may follow surgical section of nerve reflecting involvement of carotid branch.

Isolated lesions of the nerve are ………

Glossopharyngeal neuralgia:

• bohm & strang

•Middle age

•M = F

• etiology : ……..

Applied anatomy

• Sharp & shooting Pain in the ear, the pharynx, nasopharynx,

tonsil

• Almost invariably unilateral

• Trigger zone - posterior oropharnx, tonsillar fossa

Treatment

Carbamazepine, gabapentin

Surgical : Microvascular decompression Rhizotomy

Cervical plexus

Contents:

1.Formation

2.Branches & relations

3.Ansa cervicalis

4.Applied anatomy

Formation of Cervical plexus

Formed by union of……

Each of cervical nerve divides into…….

Ascending branch of the second nerve joins the first nerve

Descending branch of second nerve joins the ascending branch of the third nerve

branches

Cutaneous branch1, lesser occipital nerve

2, greater auricular nerve

3, transverse cutaneous nerve

4, supraclavicular nerve

Muscular branch1, branches to prevertebral nerve

2. Branches to muscle forming boundaries of the posterior triangle

3, pherenic nerve

4, branches to infra hyoid muscle

Course and distribution

muscular branches

Pherenic nerve

•Arises from the…..

•Descends vertically through the lower part of neck and then through the thorax to reach the diaphragm & it enters abdomen also

Formation of Ansa cervicalis

It formed by…….

Superior root is derived from….

Inferior root derived from …..

Two roots join in front of CCA

Applied anatomyAn effective cervical plexus block produces anesthesia over the • neck, • occipital region, • shoulder region• upper pectoral region.

Analgesic solution is infiltrated subcutaneously around the midpoint of the posterior border of sternocleidomastoid

Occasional inadvertent injections into the phrenic and vagus nerves

Miosis (constriction of pupils)Ptosis (drooping of eyelid)Anhydrosis (affected side)enopthalmos

Horner’s syndrome

1. Gray’s anatomy– The anatomical basis of clinical practice, 39th

edition

2.Textbook of anatomy- Inderbir singh, 4th edition

3.B.D. Chaurasias human anatomy, vol 3, 4th edition

4.Cunningham’s Manual Of Practical Anatomy. Vol 3: Head & Neck

& Brain. 15th ed.

5.Clinically oriented anatomy – Moore 6th edition

6.Clinical anatomy by regions – Snells 9th edition

7.The facial nerve – Mays 2nd edition

8. Textbook of human neuroanatomy – Inderbeer Singh 8th edition

9. Head and neck anatomy for dental medicine – Baker

References

Thank you…..