Bell’s Palsy

Overview:  In this topic we covered –

1. Facial Nerve branches
2. Bell’s Palsy
3. Bell’s Phenomenon
4. Lagophthalmos
5. Exposure Keratopathy
6. Corneal Ulcers
7. Epiphora or Watering Eye
8. Paralytic Ectropion
9. Treatment

Facial Nerve: Branches Overview

1. Greater Petrosal Nerve: Join Deep Petrosal Nerve ( from Sympathetic nerve plexus around Internal Carotid Artery ) and form Nerve of Pterygoid Canal
2. Br. to Stapedius Muscle ( Muscle present in Middle Ear Cavity and supply by Facial Nerve )
3. Chorda Tympani Nerve ( CTN ): Carry Taste Sensation ( Special Sensory / Afferent ) from Anterior 2/3 of Tongue
4. Posterior Auricular Nerve: Supply to Occipitofrontalis Muscle ( Occipital Belly )
5. Br. to Diagastric Muscle: Supply Posterior Belly of Digastric Muscle
6. Br. to  Stylohyoid: Supply Stylohyoid Muscle
7. Terminal Branches: Temporofacial Nerve ( Temporal, Zygomatic branches ) and Cervicofacial Nerve ( Buccal, Marginal Mandibular and Cervical branches ): Supply Facial Muscles

You can easily remember Bell’s Palsy in below 14 Point

[ Point 3 to 12: Denotes Symptoms and Sign of Bell’s Palsy from up to down on the face ] * for detail see the image

1. Infra nuclear or LMN ( Lower Motor Neuron ) lesion of the facial nerve or 7th Cranial Nerve ( as result facial muscles are paralyzed and facial expressions are lost )
   • [ You will also read it in NeuroAnatomy and ENT: Cranial Nerve and its Disorder ]
2. The Upper and lower quarter of the face on the same side ( Right upper and lower / Left Upper and lower ) are paralyzed, as result affected parts of the face are motionless ( due to facial muscles palsy )
   • [ You will also read it in Anatomy: Head and Neck: Facial Muscles: SCALP and Around Eye, Nose, Mouth ]
3.  Forehead wrinkles absent
   • Reason: Occipito frontalis muscle paralysis ( Supply by Temporal and Posterior Auricular branch of the facial nerve )
4. The patient is unable to close his eye
   • Reason: due to paralysis of Orbicularis oculi muscle
     1. When the patient closes his eye forcefully: Eyeball turn up and out Called: Bell’s Phenomenon
        • [ You will also read it in Ophthalmology: Eyelid ]
     2. Lagophthalmos: the patient is unable to close eyelid completely
        • [ You will also read it in Ophthalmology: Eyelid ]
     3. Exposure Keratopathy: Due to corneal surface of eyeball not fully covered by Eyelid ( as result corneal surface damage )
        • [ You will also read it in Ophthalmology: Cornea ]
     4. Drying of Cornea: lead to Corneal Ulcers
        • Reason: Corneal surface of eyeball not fully covered by Eyelid as a result Cornea remains intact with the environment for a long time cornea dry
        • + Use Lubricating Eye drops / Artificial Tear: It keeps the corneal surface wet. ( See point 14. )
        • [ You will also read it in Ophthalmology: Cornea ]
5. Tear overflow on the cheek: Called Epiphora / Watering Eye
   • Reason: due to Paralytic Ectropion ( Out rolling of the eyelid margin ) tear drainage decreases and tear flow on the cheek
   • [ You will also read it in Ophthalmology: Eye Lid ]
6. Hyperacusis
   • Reason: due to paralysis of stapedius muscle ( Supply by Facial Nerve )
7.  Nasolabial fold absent ( present between nose and mouth )
8. Sagging of angle of mouth
9. Drooping of Saliva from the angle of the mouth ( due to palsy of Orbicularis Oris Muscle )
   • Reason: due to paralysis of Orbicularis Oris Muscle ( for more detail read 10. point )
10. Articulation of labial is impaired: as a result air leak between two lips
    • Reason: due to paralysis of Orbicularis Oris Muscle ( Supply by Facial Nerve )
11. During Mastication food accumulate between teeth and cheek ( Vestibule )
12. Taste sensation loss from Anterior 2/3 of tongue
    • Reason: because taste sensation from Anterior 2/3 of the tongue are carried out by Chorda Tympani Nerve ( branch of the facial nerve )
13. Paralyzed upper and lower quarter of face pulled towards health side: Facial Asymmetry
    • Reason: Paralysed side of the face is pulled by the muscle of the health side of the face.
14. Treatment :

• Lubricating eye drops or Artificial tears: It keeps the corneal surface wet. ( see point 4. )
• Steroids: Prednisone ( decrease inflammation and oedema)
• Steroids: Prednisone ( decrease inflammation and oedema)

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