BELL’S PALSY

Facial nerve

Facial nerve

• CN 7

• Somatic fibers: Skin of the EXTERNAL EAR

• Sensory (Special): Taste from ant. 2/3 of the tongue

• Motor fibers: Mm of facial expression, Stapedius, post belly of digastric mm

• Parasympathetic: Lacrimal, Sublingual, Submandibular, Minor salivary, Mucous glands of oral and nasal cavity;

  • others: partly subserves parotid gland

BELL’S PALSY

• aka FACIAL NERVE PARALYSIS or IDIOPATHIC FACIAL NERVE PARALYSIS

• most common pathologic condition involving cranial nerve VII.

• most affected CN bcoz superficially located

• Considered LMNL

• affects mm funx: orbicularis oculi, risorious, corrugator supercilii

Bell’s palsy: Etiology

• unknown/ idiopathic

• Well accepted reason: VIRAL EXPOSURE or prob along the PATHWAY

• Others: Prolonged exposure to dec temp —> dec blood flow (vasoconstriction) —> ischemia —> palsy

Bell’s Palsy: Manifestation

1. Hemifacial Paralysis (most obv)

2. Crocodile tears

3. Salivary glands: underproduction/overproduction

4. Hyperacusis

5. Difficulty in smiling

Nuclei of facial nerve: location

• below the pons / pontine level

  • considered = LMNL

Incidence: Bell’s

• Most common age = 10-40 yrs old

  • curve = middle aged (25-40yrs old)

• 20 cases per 100,00

Specific Etiologic Cause:

1. Viral infections

   1. HSV (Herpes Simplex Virus)

   2. Epstein-Barr Virus

   3. Varicella Zoster Virus

   4. Intranasal inactivated influenza vaccine

2. Bacteria

   1. Borrelia Burdorferi

3. Anatomic

   1. Small sytlomastoid foramen d/t:

      1. Edema

      2. Otitis Media

      3. Swelling of inner ear d/t infection

4. Gestational diabetes

5. Any cond that can lead to ischemia

   1. Traumatic, non, secondary to viral exposure

Can impair neural conduction:

1. Inflammation

2. Demyelinating (dec nutrient and o2)

3. Ischemic

4. Compressive forces

Facial nerve: Structures passed thru

1. Stylomastoid foramen

2. Chora Tympani

3. Stapedius

4. Geniculate Ganglion

5. Internal Auditory Meatus

6. Pons

Manifestations: STYLOMASTOID FORAMEN (4)

• Level 1 lesion

  • Facial asymmetry

  • Outpouching (accumulation of saliva)

  • Drooling of saliva on affected side

  • Doll’s eye phenomenon

Doll’s eye phenomenon

upward rolling of the eyeball upon attempted eye closure; stylomastoid foramen

Manifestations: CHORDA TYMPANI

• lvl 2 lesion

  • dryness of mouth

  • loss of taste sensation of the ant. 2/3 of the tongue

Manifestations: Stapedius

• lvl 3 lesion

  • Hyperacusis

Hyperacusis

inc sensitivity to sound; Stapedius mm

Manifestation: Geniculate Ganglion

• lvl 4 lesion

• d/t RAMSAY HUNT SYNDROME

  • Exposure to varicella zoster, increases affinity on geniculate ganglion where the synapse of the facial nerve is located.

Manifestations: INTERNAL AUDITORY MEATUS

• lvl 5 lesion

  • Sensorineural deafness

Sensorineural deafness

results from damage to the hair cells within the inner ear, the vestibulocochlear nerve, or the brain's central processing centers

Manifestations: PONS

• lvl 6 lesion

• highest lvl of lesion

  • PATHOLOGIC REFLEX

GENERAL MANIFESTATION (4)

1. FACIAL SYNKINESIS

2. EIPIPHORA / CROCODILE TEARS

3. PSEUDOPTOSIS

4. LAGOPTHALMOS

FACIAL SYNKINESIS

• common consequence of Bell’s palsy d/t aberrant regeneration of the facial nerve

• twitching/fasciculation of face

• “Bell’s Palsy is self limiting”

EIPIPHORA

• crocodile tears

• d/t problem with the lacrimal glands

• the leaking of tears while eating or drinking in Bell palsy patients

• gustatory lacrimation

Pseudoptosis

Involves the reduction in the opening of the upper eyelid

Lagopthalmos

• incomplete eye closure

Specific Manifestations

• Facial nerve: sensory and motor impairment

• Pt may c/o

  • Dysgeusia

  • Ageusia

  • Hyperacusis

• Bell’s Phenomenon (Doll’s eye)

• Marcus-Gunn Phenomenon

• Marin-Amat Phenomenon

Dysgeusia

Impairment of taste

Ageusia

loss of taste

Hyperacusis

inc sensitivity to sound

Marcus Gunn Phenomenon

• pontine lvl

• Involuntary eye opening upon attempted lateral deviation of the jaw

Marin-Amat Phenomenon

• pontine lvl

• EYE CLOSURE upon attempted mouth opening or deviation of the jaw on one side

DIAGNOSIS CRITERIA

• There is a diffuse facial nerve involvement manifested by paralysis of the facial muscles,

• with or without loss of taste on the anterior two-thirds of the tongue or

• altered secretion of the lacrimal and salivary glands

BELL’S PALSY: timeline

• Acute = 1-2 days

• within 3 weeks or less = reach max weakness/paralysis

• Complete recovery = 6 months

• Prodrome(early) symptom = ear pain, dysacusis

RED FLAGS

1. Bilateral BP

2. Recurrent BP

3. Assocation c rash elsewhere or with feeling generally unwell (SARCOID OR LYME DSE)

4. Previous episode = demyelination

TREATMENT

1. Medications

   1. Corticosteriod = prednisone, prednisolone

   2. Vit. B

2. Physical Therapy

   1. IRR (Luminous IRR)

   2. ES

   3. Exercises

      1. PNF/Facial nerve exercises

      2. Candle blowing exercises