| Bell's (Facial Nerve) palsy
|Ramsay Hunt syndrome
|Facial nerve anatomy
Lower motor neuron VII palsy can be due to Bell's palsy
- Developmentally derived from the second pharyngeal arch, or branchial arch.
- Arises from the lateral border of the lower pons
- Has a large motor component, sensory and parasympathetic (nervus intermedius)
- Passes into the internal auditory meatus with the vestibulocochlear nerve
- Facial nerve exits the skull at the stylomastoid foramen
- Passes deep within the parotid salivary gland
- Supplies motor to muscles of facial expression through temporal, zygomatic, buccal, mandibular and cervical branches
Upper motor neuron VII palsy can be due to Stroke
- The eye closure is unaffected
- The patient can raise eyebrows
- The mouth drops on the affected side
- Intracranial Component of Nerve
- Greater petrosal nerve
- Parasympathetic to lacrimal gland (tears)
- Sensory fibres to geniculate ganglion
- Nerve to stapedius
- Involved in controlling amplitude of sound.
- Damage leads to hyperacusis
- Chorda tympani
- Taste anterior 2/3rd of tongue
- Parasympathetic to submandibular and sublingual salivary glands (salivation)
- Extracranial Component of Nerve
- Supplies Muscles of facial expression. Splits within the parotid gland
- Temporal branch.
- Zygomatic branch.
- Buccal branch.
- Marginal mandibular branch.
- Cervical branch.
- Nerve supplies muscles to
- Muscles of facial expression
- Posterior belly of the digastric