Superior orbital

fissure syndrome

Never involving V2, other than that similar to cavernous sinus syndrome. Exophthalmos and

blindness can be present

V1: Bilateral

corneal

anesthesia

Diabetic neuropathy

V2: Numb cheek

syndrome

Infraorbital nerve

Distribution: Squamous cell carcinoma, skin and LASIK

V2: Trumpet

player’s

neuropathy

Anterior superior alveolar nerve

V3: Tongue

numbness

Lingual nerve in temporal

Arteritis

V3: Numb chin

syndrome/roger’s

sign

Mental neuropathy: Cancer of breast and lung, giant cell arteritis, Burkitt lymphoma, and

sickle cell disease

FACIAL NERVE

Motor (70%) Sensory Parasympathetic

Muscles of facial

expression

Scalp

Ear

Buccinators

Platysma

Stapedius

Stylohyoid

Posterior belly of

digastrics

Taste: Anterior 2/3

Exteroceptive:

Eardrum

EAC

Proprioception: From the muscles

supplied by it

GVS:

Salivary glands

Mucosa of nose and pharynx

Submandibular

Sublingual

Lacrimal

Mucous membrane of oral and nasal

mucosa

(EAC: external auditory canal)

Note:

There is anatomical segregation of motor component from sensory and autonomic fibers.

Sensory root (nervus intermedius of Wrisberg)—contains both sensory and autonomic

fibers.

Examination of Motor Function

Inspection:

Facial asymmetry, nasolabial fold with forehead wrinkles, and movements during spontaneous facial expression

Tone of the muscles of facial expression

Atrophy and fasciculations

Abnormal muscle contractions and involuntary movements

Spontaneous blinking for frequency and symmetry

Testing the temporal branches of the facial nerve: Patient is asked to frown and wrinkle his or her forehead

Testing the zygomatic branches of the facial nerve: Patient is asked to close their eyes tightly

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Testing the buccal branches of the facial nerve:

Puff up cheeks (buccinator)

Smile and show teeth (orbicularis oris)

Tap with finger over each cheek to detect ease of air expulsion on the affected side

Muscle tested Instruction Response in palsy

Frontal belly of

occipitofrontalis

(Fig. 6D(iii).50)

Ask the patient to wrinkle his/her

forehead

Asymmetry as he/she cannot wrinkle his

forehead on the side of palsy in lower motor

neuron (LMN) palsy

Orbicularis oculi [Fig.

6D(iii).51]

Ask the patient to close his/her

eyes forcibly while you try to open

the eyelids with your fingers

In LMN palsy, eyelids do not close completely.

Instead the eyeball rolls up. This is known as

Bell’s phenomenon. In healthy individuals,

eyelids cannot be opened with mild force

against patient’s resistance

Levator anguli oris,

zygomatic major and

minor, depressor anguli

oris, buccinator, and

risorius [Fig. 6D(iii).52]

Ask the patient to show his/her

teeth or smile

Angle of mouth deviates toward normal side

Orbicularis oris and

buccinators [Fig.

6D(iii).53]

Ask the patient to blowout cheeks

with mouth closed, i.e. puff the

cheeks and assess power by your

attempt to deflate the cheek. Ask

the patient to whistle

Patient cannot blowout his cheek as air

escapes from affected side

Platysma [Fig. 6D(iii).54] Ask the patient to clench his/her

teeth and simultaneously depress

the angles of mouth

Folds of platysma is seen in the neck as flat

Fig. 6D(iii).50: Examination of frontal belly of occipitofrontalis.

Fig. 6D(iii).51: Examination of orbicularis oculi.

Fig. 6D(iii).52: Examination of levator anguli oris.

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Fig. 6D(iii).53: Examination of buccinator.

Fig. 6D(iii).54: Examination of platysma.

Fig. 6D(iii).55: Examination of taste

sensation.

Examination of Sensory System

Anterior two-thirds of tongue [Fig. 6D(iii).55]

Tongue protruded

Hold with soft gauze

With applicator’s tip apply over the dorsum of the tongue

Rinse after each test with water

Sensations from the tip to deep—follow sweet → salt → sour → bitter (last)

Fifth modality—umami appreciated with compounds of some amino acids

Normally taste is appreciated within 10 seconds

Artificial sweeteners make better test substances than ordinary sugar.

Aguesia Complete inability to perceive taste

1.

2.

Hypogeusia Blunted or delayed taste

Parageusia Perversions of taste

Impaired taste Lesion is proximal to junction with chorda tympani

Not affected Lesion is at or distal to stylomastoid foramen

Secretory Function

Lacrimation: Schirmer’s test→10 mm is normal

Nasolacrimal test: By diluted solution of ammonium and formaldehyde—trigeminal nerve → greater superficial petrosal nerve.

Reflexes

Orbicularis oculi reflex

Percussion causes reflex contraction of the eye muscle. The reflex is known as the supraorbital, glabellar, or

nasopalpebral reflex, depending upon the site of the stimulus. Both eyes usually close, with the contralateral

response being weaker. The trigeminal nerve is the afferent side and the facial nerve the efferent side of the

reflex. Light and sound can also produce the reflex, with the optic and acoustic nerves providing the afferent side

The response is weak or abolished in nuclear and peripheral lesions, and present or exaggerated in supranuclear

lesions. It is exaggerated in Parkinsonism and cannot be voluntarily inhibited

Palpebral oculogyric reflex

The eyeballs deviate upward when the eyes are closed, both when awake and asleep. The afferent arc is

proprioceptive impulses carried through the facial nerve to the medial longitudinal fasciculus. The oculomotor

nerve to the superior rectus muscles forms the efferent side

In peripheral and nuclear lesions, an exaggeration of this reflex is known as Bell’s phenomenon

Orbicularis oris reflex

Percussion on the side of the nose or the upper lip causes ipsilateral elevation of the angle of the mouth and

upper lip. The reflex arc is composed of the fifth and seventh nerves. Synonyms: nasomental, buccal, oral, or

perioral reflex

This reflex disappears after about the first year of life, recurring with supranuclear facial nerve lesions and with

extrapyramidal diseases, such as Parkinsonism

Snout reflex

Tapping the upper lip lightly with a reflex hammer, tongue blade, or finger causes bilateral contraction of the

muscles around the mouth and base of the nose. The mouth resembles a snout

This is an exaggeration of the orbicularis oris reflex. It is present with bilateral supranuclear lesions and in diffuse

cerebral diseases, such as various causes of dementia

Sucking reflex

Sucking movements of lips, tongue, and mouth are brought about by lightly touching or tapping on the lips. At

times, merely bringing an object near the lips produces the reflex

Occurs in patients with diffuse cerebral lesions. The snout reflex occurs in similar circumstances

Palmomental reflex

A stimulus of the thenar area of the hand causes a reflex contraction ipsilaterally of the orbicularis oris and

mentalis muscles

A number of normal individuals have this reflex, and also patients with diffuse cerebral disease. It is significant

when other similar reflexes are also present

Corneal reflex

Stimulation of the cornea with a wisp of cotton produces reflex closure of both ipsilateral (strongest) and

contralateral eyelids. The fifth nerve carries the afferent impulses, and the facial nerve the efferent impulses

Site of cranial nerve 7 lesion and associated manifestatio n

Lesion location Manifestations

Above the facial nucleus

(supranuclear lesion)

Contralateral paralysis of lower facial muscles with relative preservation of upper

muscles. Lesion located cortex, internal capsule or midbrain

Pons (nuclear or fascicular

lesion)

Ventral pontine lesion (of Millard–Gubler): Ipsilateral facial monoplegia, lateral

rectus palsy (VI), and contralateral hemiplegia (corticospinal fibers). Pontine

tegmentum lesion (of Foville): Ipsilateral facial monoplegia; contralateral

hemiplegia (corticospinal fibers); paralysis of conjugate gaze to side of lesion

(pontine paramedian reticular formation)

Cerebellopontine angle

(peripheral nerve lesion)

Ipsilateral facial monoplegia, loss of taste to anterior two-thirds of tongue,

impairment of salivary and tear secretion, hyperacusis (if VIII is not affected).

Additional cranial nerves may be involved: deafness, tinnitus, and vertigo (VIII):

sensory loss over face and absence of corneal reflex (V); ipsilateral ataxia

(cerebellar peduncle)

Facial canal between

internal auditory meatus

and geniculate ganglion

(peripheral nerve type

lesion here and

subsequently)

Same as above except cranial nerves other than VII are not involved

Facial canal between

geniculate ganglion and

nerve to stapedius muscle

Facial monoplegia; impaired salivary secretion; loss of taste; and hyperacusis

Facial canal between nerve

to stapedius and leaving of

chorda tympani

Facial monoplegia; impaired salivary secretion; and loss of taste

After branching of chorda

tympani

Facial paralysis, distribution related to site of lesion

Fig. 6D(iii).56: Facial nerve pathway.

FACIAL NERVE PALSY

Peripheral Facial Palsy

There is flaccid weakness of all the muscles of facial expression on the involved side, both

upper and lower face, and the paralysis is usually complete.

Signs in Lmn Facial Palsy

Bell’s

phenomenon

Attempting to close involved eye causes a reflex upturning of the eyeball

Levator sign of

Dutemps and

Céstan

Patient look down, then close the eyes slowly; because the function of levator palpebrae

superioris is no longer counteracted by orbicularis oculi, upper lid on the paralyzed side

moves upward slightly

Negro’s sign Eyeball on the paralyzed side deviates outward and elevates more than the normal one when

the patient raises her eyes

BergaraWartenberg sign

Loss of the fine vibrations palpable with the thumbs or fingertips resting lightly on the lids as

the patient tries to close the eyes as tightly as possible

Platysma sign

of Babinski

Asymmetric contraction of the platysma, less on the involved side, when the mouth is opened

House–Brackmann grading system of LMN facial palsy

Grade I Normal

Grade

II

Mild dysfunction, slight weakness on close inspection, and normal symmetry at rest

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